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A Guide to Residential Wood Heating

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Natural Resources Canada Ressources naturelles Canada Residential Wood Heating Residential Wood Heating A Guide to
Page 1: A Guide to Residential Wood Heating

Natural ResourcesCanada

Ressources naturellesCanada

ResidentialWood Heating

ResidentialWood Heating

A Guide to

Page 2: A Guide to Residential Wood Heating

A Guide to Residential Wood Heating

This guide is distributed for information purposes only and does not necessarily reflect the views of the Government of Canada or constitute an endorsement of any commercial productor person. Neither Canada nor its ministers, officers, employees or agents make any warrantywith respect to this guide or assumes any liability arising from this guide.

© Her Majesty the Queen in Right of Canada, 2002

Cat. No. M92-23/2002EISBN 0-662-31793-9

Aussi disponible en français sous le titre : Le Guide du chauffage au bois résidentiel

Page 3: A Guide to Residential Wood Heating

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Chapter 1 Safety Tips – Burn It Smart! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Chapter 2 Wood Burning in Canada . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Chapter 3 Wood Burning and the Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Chapter 4 Advanced Wood-Heating Technologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Chapter 5 Heating Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Chapter 6 Wood-Heating Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Chapter 7 Installation Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Chapter 8 Your Installation Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Chapter 9 The Chimney . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Chapter 10 Preventing Smoke, Smells and Cold Hearths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Chapter 11 Maintaining Your Wood-Heating System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Chapter 12 Burning Wood Efficiently . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Chapter 13 Purchasing and Preparing Your Fuel Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Chapter 14 Comparing Annual Heating Costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Chapter 15 The Future of Residential Wood Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

For More Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59


Table of Contents

Page 4: A Guide to Residential Wood Heating

If you are thinking about buying awood-heating appliance or alreadyheat your home with wood, youmay be one of 3 million Canadianhouseholds that appreciate theambience and warmth of woodheat. Wood heating has a longhistory in Canada and, with newavailable technologies, morehouseholds are returning towood for renewable energy.

Wood-heating technologies havechanged a lot in the past decade.Today’s advanced combustionsystems burn more cleanly andefficiently than ever.

If you are shopping for a wood-heating appliance or areplanning to replace or upgradeyour current unit, consider onlya highly efficient combustionappliance. You can identify theseadvanced systems by looking forproof of certification to the per-formance standards set by bothCSA International, formerly theCanadian Standards Association,(“CSA B415.1 PerformanceTesting of Solid-Fuel-BurningHeating Appliances”) and theU.S. Environmental ProtectionAgency (EPA 1990). Certified systems will give you a cleaner,more efficient burn.

If you are already enjoying thebenefits of wood heat in yourhome, use this guide to help you make informed decisions onsuch matters as the following:

• consulting wood-heating professionals;

• how to maintain your systemfor safety and peak efficiency;

• how to purchase and storeyour fuel wood;

• how to use fire managementtechniques for cleaner, virtually smokeless fires; and

• many other useful tips.

This guide is part of a series ofbuyer’s guides on renewableenergy systems for residential use.More documents on residentialwood heating include these titles:

• All About Wood Fireplaces

• An Introduction to HomeHeating With Wood

• Buying a High-Efficiency Wood-Burning Appliance

• Getting the Most Out of YourWood Stove

For electronic versions of theseguides, visit the Web site athttp://www.nrcan.gc.ca/es/erb/reed/public_e.htm. You can alsoorder copies free of charge bycalling 1 800 387-2000 toll-free.



Page 5: A Guide to Residential Wood Heating

Enjoy the benefits of your woodfire in comfort just by taking a few simple precautions.Otherwise, in the blink of aneye, those warm friendly flamesin your fireplace or wood stovecould turn into a devastatingfire. You can easily prevent dangerous situations such aschimney fires by taking theproper safety measures.

Here are some good tips on waysto burn cleaner wood fires.

SafetyKeep creosote at bayCreosote, a crusty deposit leftbehind by the smoke that driftsup your chimney, can ignite intoa dangerous fire when it buildsup. To reduce it:

✔ Burn only clean, well-seasoned wood that has beensplit and dried properly. Drywood lights faster, burns bet-ter and produces less smokethan “green” wood – a majorculprit in creosote buildup.

✔ Think twice before you chopup that old coffee table andtoss it into your wood stove.Burning garbage, plastic, parti-cleboard, plywood, salteddriftwood or any otherpainted or treated woodreleases a toxic cloud ofchemicals and can build up creosote.

Don’t let a small sparkignite a big blaze✔ The best way to start your

fire is with newspaper anddry kindling. Never try to geta blaze roaring with gasoline,kerosene or charcoal starter –you will get more firepowerthan you bargained for.

✔ Remove ashes from yourstove or fireplace regularlyand store them in a coveredmetal container in a safe areaaway from the side of yourhouse. The sparks in hotashes can easily start fires.

✔ Keep all household items –drapes, furniture, newspaper and books – away from theheat and the stray sparks ofyour woodstove or fireplace.

✔ Protect floors from sparkswith a properly fitted screenaround your fireplace. A decorative screen does notprovide protection.

Detection devices save lives✔ Install carbon monoxide

detectors and smoke alarms,as required by the NationalFire Code of Canada, and keepa fire extinguisher nearby.You should never smellsmoke in your house. If you do, it usually meansyour wood stove or fireplacesystem isn’t venting properly –perhaps the chimney isblocked, a damper is faulty or the fireplace is competingwith your range hood. Notonly are these fire hazards,but they could also lead todeadly carbon monoxide poisoning.

A hot new stove✔ If you are using an open fire-

place or your wood stove ispast its prime, you might consider buying a new modelwith improved safety and efficiency features. The bestchoice is a high-efficiencystove or fireplace approved for safety by the Underwriters’Laboratories of Canada (ULC)or another testing body, andcertified as low-emission bythe U.S. EnvironmentalProtection Agency (EPA).

Go to the professionals✔ Any new stove or fireplace

should be professionallyinstalled. Make sure yourexisting unit is inspected andcleaned at least once a yearby a technician certifiedunder the Wood EnergyTechnical Training (WETT)program or, in Quebec, theAssociation des profession-nels du chauffage.


1 Safety Tips – Burn It Smart!

Page 6: A Guide to Residential Wood Heating

Healthier Wood Heat The hottest pollution preventer✔ The best way to reduce wood

smoke is by using a high-efficiency wood stove or fireplace, certified low-emission by the EPA. Usedproperly, these products cutemissions by up to 90 percent,and you will see virtually nosmoke coming from yourchimney.

✔ More efficient than conventional models, high-efficiency products use up to one third less wood –meaning less smoke, lesswork and hearty cost savings.

Burn small and burn smart✔ Keep the fire hot and small.

Feed it regularly with splitwood and never let it smoul-der. A smouldering firecreates more smoke.

✔ Don’t overload your stove or fireplace. Air should move around inside for a cleaner burn.

Where there’s smoke…there’s pollution ✔ Burn dry, well-seasoned wood

that has been split properly.Green wood producesunhealthy smoke because it is too wet.

✔ Burning garbage, plastic, par-ticleboard, plywood or anyother painted or treatedwood releases a toxic cloudof chemicals – don’t tossthese items into your fire.

Be energy efficient✔ Make sure your home is

energy efficient by insulatingwalls, caulking windows andrepairing weatherstrippingaround the doors. Don’t letyour heat slip through thecracks!

Local Air Quality Advisory✔ Under certain weather condi-

tions, you will notice thatthe smoke is slow to thin out and hangs in the air forlonger than usual. SometimesCanadian municipalities willissue local air quality advi-sories in which people areasked not to burn wood duringthis time. It’s important torespect these advisories.


Page 7: A Guide to Residential Wood Heating

Wood was Canada’s originalheating fuel. Wood burning continues to be an effective andeconomical way to heat yourhome – as a primary heatingsource or as a secondary heatingsource to complement conven-tional oil or gas furnaces, orelectric baseboards.

Advances inWood Burning Major advances in the 1990shave made wood burning cleanerand more effective, efficient and convenient than ever. Thefollowing are some of theseadvances:

• combustion designs that canburn more of the wood – andburn it more cleanly and athigher efficiencies;

• performance standards (CSA B415.1 and EPA 1990)that identify newer, cleaner-burning units;

• technology that providesmore efficient heating whileallowing you to view theflame from behind a specialceramic glass door that willstay clear for long periods;

• pellet stoves that use com-pressed wood and otherbiomass wastes, capable ofproviding at least 24 hours of unattended, automatedheating;

• standards that provide clearguidelines for safe installa-tion; and

• professional training programsfor installers and inspectors toensure that you get depend-able advice and service.

As recently as the mid-1970s,basement wood furnaces or sim-ple box stoves burned most ofthe wood in homes. Then camethe evolution to airtight stoves,which were more efficient butcreated more air pollution.Pressured by environmentalobservers over the issue of smokepollution, stove designers began to develop cleaner-burning products. By the early 1990s,Canadian manufacturers led the way, and new productsreached the market.

Today, the efficiency ofwood-heating systems hasimproved significantly. Mostof the new wood-heatingappliances are attractivestoves and fireplaces designedfor the main living areas of a home. They use advancedtechnology and are cleaner-burning. Such appliances,properly installed in the rightplace, can provide primary or secondary heat for yourhome – while offering thebeauty of a visible fire.

Our houses have also becomemore energy efficient, with moreinsulation, more effective air barriers, and sealed doors andwindows. These changes makehouses easier to heat. But theyalso mean that wood-burningsystems must be better designedand sized and their installationcarefully planned so that theyfunction properly within atightly sealed house.

The Keys to Safeand SuccessfulWood BurningThe keys to safe and successfulwood burning are good planning,carefully selecting a high-efficiencyappliance, installing and properlyoperating the appliance and prac-tising clean-burning habits. Thisguide is intended to help you plan and use your wood-burningsystem in the safest, cleanest andmost effective way.

Scientific research and the co-operative efforts of govern-ments and industry make woodburning safer, cleaner, moreconvenient and more efficientthan ever.


2 Wood Burning in Canada

Page 8: A Guide to Residential Wood Heating

Any fuel you choose to heat yourhome will affect the environ-ment. When wood is not burnedproperly, it can have negativeimpacts on both outdoor andindoor air quality. Smouldering,smoky fires that produce a plumeof blue-grey smoke from thechimney are the main cause ofair pollution related to woodburning. You can reduce theamount of smoke from woodheating in many ways.

• If possible, upgrade to a new,cleaner-burning stove or fireplace. Cleaner-burningappliances are certified to CSAInternational’s CSA B415.1smoke emissions standard orto U.S. EnvironmentalProtection Agency rules. Theseappliances reduce smoke emis-sions by as much as 90 percentcompared with conventionalwood stoves, fireplaces andfurnaces. Ask your hearthproducts retailer for details.

• Select an appliance that is the right size for your home’sheating needs, and place it inthe main living area to makethe best use of the heat it produces.

• Use a modern chimneymatched to your appliance.

• Avoid smouldering fires byusing the clean-burn tech-niques covered in Chapter 10,“Preventing Smoke, Smells andCold Hearths.” Burning woodcleanly reduces up to half theamount of smoke produced.

• Use well-seasoned, dry, cleanfirewood that is split to theright size for your appliance.

• Make your house moreenergy efficient so that youuse less fuel to heat it. Usingless fuel wood means lessenvironmental impact andless work on your part.

Wood Burning,Climate Changeand the Carbon CycleNearly every day, we read newsreports about the need to reduceemissions of greenhouse gases(GHGs) to prevent climatechange and related problems.The main source of GHGs is theburning of oil, gas and coal toproduce the energy we use. These fuels are called fossil fuelsbecause they are taken from deepbeneath the earth’s surface,where they have been formedover millions of years. When fossil fuels are burned, GHGs are released. The main GHG is carbon dioxide (CO2). Increasedconcentrations of these gases inthe atmosphere trap the sun’sheat close to the earth and causethe average global temperature to rise.

Wood, however, differs from fossil fuels such as oil and gasbecause it is carbon neutral. Theterm “renewable” refers to thefact that trees recycle CO2. As atree grows, it uses CO2 from theair as a source of carbon to buildits structure. This carbon makesup about half of the weight ofwood. When wood is burned, itdecomposes rapidly, and CO2 isreleased into the atmosphereagain. A similar amount of CO2

would be slowly released if thetree died and was left to rot onthe forest floor. As a result, woodheating doesn’t contribute to theproblem of climate change theway fossil fuel use does. Butwood fuel is truly renewable only if it is produced by usingsustainable forestry practices.Canada’s forests can be a perpet-ual source of fuel – as long asthey are cared for and managedproperly.

Wood is a renewable energyresource. And because treesrecycle carbon dioxide, woodburning doesn’t contribute tothe problem of climate change.As well, advanced combustiontechnologies mean more heatand less smoke from the woodyou burn.


3 Wood Burning and the Environment

▲The Carbon Cycle

Page 9: A Guide to Residential Wood Heating

In the mid-1980s, researchersand appliance designers began to develop new technologies to significantly reduce the amountof smoke and other pollutantsthat wood-burning appliancesproduce. Complete combustionneeds three simultaneous condi-tions: high temperature, enoughoxygen (air) and time for thecombustion gases to burn beforebeing cooled.

Today, these highly efficienttechnologies come in three categories: advanced combustion,catalytic, and densified pelletsystems.

AdvancedCombustionSystemsHighly efficient combustion systems create the conditionsneeded to burn the smoke beforeit leaves the appliance. The technology has the followingcharacteristics:

• firebox insulation to keeptemperatures high;

• primary combustion air thatis preheated so that it doesn’tcool the fire;

• preheated secondary air thatis fed to the fire through sets of small holes in the gas-burning zone, above andbehind the fuel bed; and

• internal baffles that give thegases a long and hot enoughroute so that they can burn completely.

When wood in a combustionstove or fireplace is burning well,you may see nearly transparentflames swirling above the woodin addition to the normal flamescoming from the wood.

Canadian manufacturers have an international reputation asdesigners of some of the mosteffective wood-burning appli-ances in the world. Ask yourhearth products retailer to point these appliances out.


4 Advanced Wood-Heating Technologies

▲Advanced combustion system

Page 10: A Guide to Residential Wood Heating

Catalytic StovesCatalytic stoves rely on a catalystto help burn smoke before itleaves the appliance. The catalystin a wood-burning appliance is a coated ceramic honeycomb-shaped device through which theexhaust gas is routed. The catalyticcoating lowers the ignition temperature of the combustiongases as they pass through it.This allows catalytic appliancesto burn cleanly at low heat outputsettings. The performance of the catalyst deteriorates overtime and emissions rise accord-ingly, so you need to replace the catalyst now and then.

Because the catalyst restricts gas flow through the appliance, catalytic stoves always include a bypass damper into the flue.The damper is opened when fuelis loaded and is closed when you get a hot fire. This forces the gases through the catalyst for an extended, cleaner burn.The restriction of gas flow canalso cause draft problems.

Densified PelletSystemsDensified pellet systems burnfuel made from dried groundwood or other biomass wastecompressed into small cylindersabout 6 mm (1/4 in.) in diameterand 25 mm (1 in.) long. Thepressure and heat created duringtheir production binds the pellets together with the ligninin the wood without using additives.

Pellet burners include a hopperto hold 20–60 kg of fuel and ascrew auger to automaticallymove the pellets from the hopper into the combustionchamber. Pellets burn cleanlybecause they are fed to thechamber at a controlled rate and are matched with the rightamount of combustion air. Ifthey are properly adjusted, pellet-burning stoves can operateat lower emissions levels thannatural firewood appliances.

Since pellet stoves have three oreven four motors, they can use a lot of electricity. If possible, try to get a pellet stove that usesefficient electric motors. DCmotors use the least amount ofenergy – only 40–120 watts intotal. To ensure that your pelletstove is efficient and clean-burning, buy one that has been tested to CSA B415.1 or EPA 1990 standards.


▲Densified pellet system

▲Catalytic stove

Page 11: A Guide to Residential Wood Heating

You have many options for heat-ing your home with wood. Theseoptions, discussed below, includespace heaters such as woodstoves and fireplaces, as well ascentral heating systems.

SPACE HEATERSMost wood-burning appliancesfunction primarily as spaceheaters. A space heater is intendedto heat a space directly, unlike acentral heating furnace or boiler,which supplies heat to the housethrough a system of ducts or pipes.In the past, when houses werepoorly insulated and drafty, aspace heater could be expectedonly to heat the room it wasinstalled in and possibly an adjacent space. Modern housesconserve energy more effectivelyand need less heat to stay warm.Now a single space heater can provide most of the heat for awell-insulated, average-sized home.

Like any effective heating sys-tem, installing a space heatertakes careful planning. If youintend to supply most of yourhome’s heating needs with aspace heater, consider these twoimportant factors:

1) The heater should be locatedwhere household membersspend most of their time.

2) The heat must be able to circulate to other parts of the house.

These conditions aren’t difficultto meet, but they do need to beplanned.

Space heaters come in several dif-ferent forms. They include woodstoves, cookstoves, pellet stoves,conventional fireplaces, high-efficiency fireplaces, fireplaceinserts and masonry heaters.

Wood StovesThe wood stove is the most com-mon wood-heating appliance. It can be safely located almost anywhere as long as there isenough space and a chimney can be properly routed. The idealplace for the space heater is inthe centre of the main-floor living area of the house, with the flue pipe running straight up from the stove flue collar into the chimney. This type of installation provides the best performance and requires theleast maintenance. However,keep in mind that all wood-heating appliances need regularupkeep for safety, efficiency andcleanliness. Wood stoves come ina wide range of sizes and designs.

Heat OutputWood stoves range from verysmall units, designed to heatonly a small area, to large stovesthat can heat large houses.However, large-output stoveswork well only if your house hasan open-plan design, where theheat can readily circulate toother areas.

Selecting a stove with the correctheat output range can be trickybecause the stove’s appearancedoesn’t always reflect its perfor-mance. If the stove’s output istoo large for the space to beheated, it will be turned downlow much of the time, producinga smoky fire. An undersizedstove, meanwhile, may deterio-rate because of constantover-firing. What is the best wayto find a stove that is sized foryour needs? Get advice from anexperienced wood stove retailer.Since these retailers know theperformance of each of theirstoves, they can help you chooseone that has the right output forthe space you want to heat.

Most Canadian homes areheated by a central system,either a furnace or boiler (usuallylocated in the basement). Theheat is distributed around thehouse through ducts (hot air) orin pipes (hot water). Spaceheaters tend to heat the area inwhich they are located.


5 Heating Options

Page 12: A Guide to Residential Wood Heating

Design The exterior designs of woodstoves owe more to aestheticsand personal preference than toperformance. For example, thereare no clear differences in perfor-mance between cast iron andplate steel constructions orbetween painted and enamelledfinishes. The real difference isthe technology inside the con-ventional wood stove as opposedto the technology in the high-efficiency wood stove.

Means of Heat Transfer Various stove designs heat the room in different ways.Depending on its design, a wood stove may deliver most of its heat by direct radiation, by the convection flow ofwarmed air, or both.

Radiation is the direct transfer ofheat from the hot stove surfaces to walls, furniture and people thatare in direct line of sight from thestove. Radiant energy will makeyou feel warm, even though the air around you is cool. Theceramic glass in the new woodstoves has special properties thatallow direct radiation from theflame to pass through it. So youget heat through the glass, as wellas from the hot metal surfaces ofthe stove.

Convection is the transfer ofheat through the motion of air.In wood stoves that deliver heatby convection, the body of thestove is surrounded by an outercasing, usually made of sheetmetal. Heat from the stove cre-ates a current of air in the spacebetween the body and the outercasing. This way, much of theheat from the stove is deliveredto the room as warmed air,rather than direct radiation. The outer surfaces of convectionstoves (and the shielded portionsof other stoves) don’t get as hotas unshielded surfaces.

When you shop for a stove, youwill notice that most new woodstoves deliver heat to a room bya combination of direct radia-tion and convection. The sidesand rear of many stoves areshielded so that they can beinstalled close to walls, and theseshields create convection flow ofwarm air. The fronts of all stoves,either with glass panels or solidmetal doors, deliver heat directlyto the room.


You may find that a cookstove isa desirable addition to your ruralhome. However, cookstovesaren’t designed for use as stand-alone home-heating devices. Andeven though their manufacturershave been developing efficient,clean-burning products, smokyfires can still be a problem.


▲Generations of rural Canadians usedwood-burning cookstoves not onlyfor preparing meals and heatingwater, but also for heating theirhomes.▲CAST-IRON WOOD STOVES – Cast-iron

wood stoves deliver much of theirheat to the room by direct radiation.Rear heat shields, however, are often used to reduce installationclearances. These shields create convection air flow.

Page 13: A Guide to Residential Wood Heating

Pellet StovesStoves that burn pellet fuels –made from wood, corn or otherbiomass wastes – have beenwidely available in Canada forseveral years. Pellet stoves havesome advantages over woodstoves that burn firewood:

• The automatic operation isconvenient.

• One hopper-load of fuel canlast 24 hours or more.

• The fuel is supplied in com-pact bags that store neatly.

• Most can use a special ventthat costs less than wood-stove chimneys.

• They can offer low emissionsand high efficiency.

Balancing these advantages aresome limitations that you shouldconsider:

• Pellet stoves tend to cost more.

• Pellet fuel is more expensivethan firewood in many areas.

• Most pellet stoves need electricity to drive augermotors and fans.

• Flames produced by pelletstoves don’t look as naturalas wood fires, although thisfeature has improved.

At the same time, pellet stovesusually have three motorized systems that require electricity.

1) a fuel feed auger to move thefuel from the storage hopperto the combustion chamber;

2) an exhaust fan to move theexhaust gases through theappliance and into the vent-ing system while drawing incombustion air; and

3) a circulating fan to force airthrough the heat exchangerand into the room.

A few pellet stoves can operateduring electrical power failuresby using batteries to operate the motors.

Although stoves are the mostcommon pellet-burning appli-ances, you may also findfireplaces and central heatingfurnaces that burn pellet fuel inyour area. Depending on yourcircumstances, a pellet-burningappliance could be a very practical heating option.


▲Pellet stoves have a more complexinterior than wood stoves. A motor-ized auger feeds the pellets to thecombustion chamber, and a fanforces the exhaust into the ventingsystem. An air circulation fan is also standard equipment on pelletstoves. On the other hand, they areeasier to use and you can control the temperature.

Page 14: A Guide to Residential Wood Heating

ConventionalFireplacesConventional fireplaces have along history in Canadian homeheating. They are built frommasonry materials such as brick,block and stone. More recently,factory-built models are con-structed mainly of steel. Thesefireplaces were designed for, andare only useful for, your enjoy-ment of the fire.

Conventional wood-burning fireplaces don’t heat a homeeffectively. Tests show that theycan cause major heat loss bydrawing heated air out of thehouse while delivering little heatto the room. This problem canactually make the house feeldrafty while the fireplace is oper-ating and can result in a near- orbelow-zero efficiency when it iscold outside. Conventional

fireplaces perform poorly becausethey don’t have the characteristicsneeded to convert the fuel touseful heat – such as tight-fittingcasketed doors, well-designedcombustion chambers and anadequate heat exchanger.

Not only are conventional fire-places inefficient and drafty, theycan create two other problems.First, their simple fireboxes don’tburn the wood completely, so airpollution can be high. Second,their large air consumption, poorcombustion and widely varyingdraft make them more likelythan other types of wood-burn-ing systems to spill smoke intothe room. These days, Canadiansare more concerned about indoorair pollution than ever. If youshare that concern, avoid using a conventional fireplace in your home.

If you already have a con-ventional fireplace andwould like to upgrade it, be a little sceptical aboutthe claims made for manyfireplace products. Whilemanufacturers advertisemany options that claim toimprove the performance of a conventional fireplace,in reality most do little toincrease efficiency ordecrease pollutants.

For example, to reduce thecold draft, you could installtempered-glass doors on thefireplace. The doors won’timprove energy efficiency,but they may reduce theleakage of air when youaren’t using the fireplace.

Note, too, that the temperedglass used in most fireplace doors(unlike the ceramic glass used fornew wood stoves) blocks muchof the radiant heat coming fromthe fire.

You may think that installing atubular grate or special fireboxliner will improve the fireplace’sheating efficiency. However, thisoption isn’t recommended becauseit makes only a minor improve-ment. And continuous use of thefireplace could dangerously overheat the surrounding area.

Installing an outside combustionair duct to the firebox is unlikelyto improve performance and can become a fire hazard undercertain wind conditions. Air fromthe outdoors can reverse flowdirection, sending hot exhaustgases through the duct.

If you use your open-pit fireplaceonly occasionally to view a fire,artificial fire logs made of waxand sawdust are a good alterna-tive to natural firewood. Efficiencywon’t be high, but pollutantswill be reduced.

However, if you want to useyour fireplace on a regular basisand want better all-round per-formance, your best option is to upgrade it with an advancedcombustion fireplace insert orhearth-mount stove. By upgrad-ing your system, you will noticemore heat, much fewer pollutantsand fewer cold drafts whileenjoying your fireplace. Moreover,you will still be able to view anattractive fire.


▲Conventional open-pit fireplace

Page 15: A Guide to Residential Wood Heating

High-EfficiencyFireplacesIf you are looking for a new fire-place installation, you can nowcombine the beauty of a fireplacewith the heating power of awood stove by selecting one ofthe new breeds of advanced factory-built fireplaces. Advancedcombustion, high-efficiency fire-places are becoming as effectivefor space heating as the new,advanced wood stoves. They usethe same internal combustionfeatures to reduce smoke emis-sions and boost efficiency.

The firebox and heat exchangerof these fireplaces are surroundedby an insulated sheet-metal casing. This means they can beinstalled within a combustibleconstruction without overheat-ing it. A lumber or steel-studframe is constructed and sheathedwith drywall or other materialsto enclose the sides and rear ofthe fireplace. The enclosure canthen be decorated with tile, brickor stone slices and a mantel tocreate either a traditional- ormodern-style fireplace. In mostcases, the fireplace and its deco-rative facing materials can beinstalled without a foundation or floor reinforcement.

These fireplaces provide heat tothe room by drawing air througha grille (below the firebox) into the circulation chamber(between the firebox and casing),where it is heated. This heatedair is directed back into the roomeither through another grilleabove the fireplace opening orthrough one or more ducts.

Some advanced fireplaces areapproved for additional ductrouting to any part of the house.

These new fireplaces, approvedto CSA International or EPA per-formance standards, can meetboth heating and aesthetic objec-tives. Their only real drawback isthe complex installation, which you should leave to trained professionals.

Fireplace InsertsA fireplace insert is like a woodstove, but designed to be installedwithin the firebox of an existingmasonry fireplace. Inserts are usedto convert masonry fireplaces intomore effective heating systems.An insert consists of a firebox surrounded by an insulated con-vection shell. Air flows throughthe shell to be warmed beforebeing returned to the room. Theouter shell ensures that most ofthe heat is delivered to the roominstead of being trapped behindthe insert in the masonry structure.


▲Factory-built fireplaces featureadvanced combustion systems,tight-fitting ceramic glass doorsand heat exchangers. Some haveoptional duct kits to distributewarm air to other parts of the home.

▲You can retrofit an existing masonry fireplace with an insert to improve its efficiency and reduce the amount of air exhausted from the house.

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A decorative faceplate covers thespace between the insert bodyand the fireplace opening.

Fireplace inserts used to have areputation for being unsafe, ineffi-cient and expensive to maintainbecause the exhaust wasn’t prop-erly vented to the outdoors. Manyolder installations allowed theexhaust gas to exit the insert fluecollar and find its way up thechimney. In an attempt to correctthis problem, homeowners some-times used a short length ofstainless steel liner to connect the flue collar to the base of thefireplace chimney. However, expe-rience has shown that, even witha direct chimney connection,inserts didn’t work properly. Asidefrom poor combustion, manyinserts did a poor job of trans-ferring heat from one room toanother. They were also hard toclean and generated a high levelof creosote. Creosote is an oily liquid with a penetrating odour,obtained by distilling wood tar.When your chimney is caked withcreosote, your risk for chimneyfires increases significantly.

Municipal installation codes nowrequire that a properly sized,stainless-steel chimney liner be

installed from the insert flue col-lar to the top of the chimney.The result is better performanceand a safer system.

The liner reduces the flue size tomatch the insert. It also isolatesthe exhaust gas from the masonrystructure of the fireplace and itschimney. Your new insert shouldbe certified for low emissions sothat you get the full benefits ofthe advanced technologies. Thisdesign evolution and technologyhave increased performance to

the extent that today’s best fire-place inserts, with ceramic glassdoors and insulated outer casing,are nearly as efficient as free-standing wood stoves.

Perhaps you already have aninsert installed in a masonry fire-place. Adding a stainless-steelchimney liner would greatlyimprove performance and safety.

A few special inserts can beinstalled in factory-built fire-places. If you are consideringusing an insert to improve theperformance of your conventionalfactory-built fireplace, be surethat it is certified for this use.

Hearth-MountStovesA hearth-mount stove is analternative to a fireplace insert. A hearth mount is a wood stoveinstalled in front of a fireplace.Or, if you have a large fireplace,it can be mounted partiallyinside its firebox and ventedthrough the fireplace chimney.Like inserts, hearth mounts mustbe vented through a liner that iscontinuous from the flue collarto the top of the chimney. It isusually more efficient than an


▲Municipal installation codes now require that a properly sized,stainless-steel chimney liner beinstalled from the insert flue collar to the top of the chimney. The result is better performance and a safer system

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insert, as heat from the casingcomes directly into the room. Youcan use only certain wood stovesas hearth mounts. The certificationlabel and installation instructionsindicate if the unit can be ventedthrough a fireplace.

High-Thermal-Mass MasonryHeatersHigh-thermal-mass masonryheaters operate on a differentprinciple from high-efficiency, factory-built fireplaces. Masonryheaters take advantage of tonnesof mass – in the form of bricks or stone – to absorb and laterrelease the heat from the fire.

These heaters also have a com-pletely different interior fromconventional masonry fireplaces.The core of the heater, consistingof the firebox and heat exchangechannels, is built from high-tem-perature firebrick and/or precastmasonry components. To com-plete the fireplace, the core isthen surrounded by brick, tile or stone.

With a masonry heater, youneed only one or two hot fireseach day to provide all of theheat that your home needs.The wood is burned quicklyand the fire is allowed to goout. But the heat stored in themasonry structure continuesto radiate warmth for manyhours thereafter.

The Masonry HeaterAssociation of North Americahas developed guidelines for the efficient design andinstallation of these heaters.Be sure that your unit meetsthese requirements. Since amasonry heater represents a considerable investment, con-sult a professional installerexperienced in its design, construction and installation.


▲Unlike conventional fireplaces,masonry heaters burn more cleanlyand are a more efficient source ofheat. The heat from the fire is trans-ferred to the mass of the masonrybefore being slowly released to theroom. Masonry heaters aren’t ratedfor emissions, but you can achieveequivalent performance by followingguidelines from the Masonry HeaterAssociation of North America.

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CENTRAL HEATINGA central heating system uses anetwork of air ducts or waterpipes to distribute heat to allareas of the house. For example,furnaces heat air that is thenforced through ducts with a fan.Boilers heat water that is forcedthrough pipes with a pump. Mosthouses in Canada have centralheating systems that use oil, gasor electricity as energy sources.

Central heating with wood-firedfurnaces and boilers is less com-mon than it used to be. Houses are now more energy efficient andeasier to heat with wood-burningspace heaters and advanced fireplaces, which also offer the aesthetics of fire viewing. As well,furnace and boiler-combustiontechnology has lagged behind theadvances in wood stoves. Presently,no commercial units come close to achieving the low emission levels – or the higher efficiencies –of advanced wood stoves.

However, central heating with awood-fired furnace may still bean option under the followingconditions:

• the house is old, large andnot energy efficient;

• the house has many smallrooms with no large open areas;

• there is no suitable place toinstall a fireplace or woodstove;

• fire viewing is a low priority;

• you have ready access tolarge amounts of low-costwood fuel; or

• you clean your furnace andventing system frequently.

Add-On Wood Furnace InstallationWood furnaces and boilers canbe installed to work automati-cally with appliances that useother fuels, such as oil, naturalgas and electricity. Combinationfurnaces (such as wood-oil orwood-electric) have two energysources in a single packaged unit.Add-on furnaces and boilers canbe installed beside existing fur-naces and boilers that use otherfuels. In general, wood-burningfurnaces must have greater clear-ances from combustible surfaces(e.g. ceiling joists, frame walls)than oil, gas or electric furnaces.All units must be safety testedand certified.

Because wood furnaces lackadvanced combustion features,they produce more smoke anddeposit more creosote in theirchimneys. If you choose a wood-burning central furnace, beprepared to service the chimney,flue pipes and furnace heatexchanger regularly during the winter.


▲The add-on is placed beside the existing furnace, and special ducts are installed toconnect the two units. The air passes through the original furnace, then throughthe add-on and into the ducts to be distributed throughout the house. Note thatonly an experienced professional should install an add-on.

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Outdoor BoilerAn outdoor boiler is contained ina small structure that looks like agarden shed. Heated water fromthe boiler is pumped through apipe underground to the house.Here it either passes through aheat exchanger, releasing its heat to a forced air stream, or is distributed to various areas sup-plying heat to baseboard or wallregisters or through floor-heatingcoils. The water is then sent backto the boiler through a secondunderground pipe to be reheated.

Uncertified outdoor boilers havebecome more popular in the pastdecade. These boilers confine themess of chips and bark fromwood storage and handling tothe outdoors. You can use theboiler to heat tap water, as wellas your home. Another advan-tage is that you can use one ofthese units to heat more thanone building.

There are many problems withoutdoor boilers that make themcontroversial and, in many cases,undesirable. Most outdoor boilerscreate a lot of smoke during oper-ation for the following reasons:

• they lack internal featuresthat promote complete combustion of the wood;

• the relatively cool boiler surfaces quench the flames;

• the units are inefficient;

• the units selected are oftentoo large for the heat load,which results in smouldering;

• their large fireboxes encour-age owners to use large piecesof unsplit, unseasoned fire-wood that burn inefficiently;

• few municipalities authorizepermits for their installation;

• their on/off operating cyclemeans excessive combustion,which creates high creosotepollution during the offcycle; and

• they smoulder for long periods when used to produce domestic hot water during the summer,producing high levels ofsmoke emissions.

Some outdoor boilers make somuch smoke and air pollutionthat many neighbours complain.Numerous rural municipalities inCanada have either consideredbanning them or are proceedingto do so.


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You might consider buying someaccessories to enhance yourwood-heating system. Some ofthe options discussed below canmake wood burning more pleas-ant and convenient, while otherscan create problems.

Tool Set There are standard sets of toolsfor managing a wood fire to heatyour home. You will use thesetools several times a day duringperiods of regular heating, so geta set that is more practical thandecorative. Tool sets for wood-heating appliances are differentfrom the more decorative setsused with conventional fire-places. Stove tool sets haveshorter handles and have an ashrake instead of a poker. Anyretailer that specializes in hearthaccessories can help you identifywhich sets are best suited foryour appliance.

Ash ContainerYou will want to set an effectiveroutine for dealing with ashes.Following are three ways toavoid creating dust as youremove the ashes:

• if your stove has an ash pan,empty it regularly (don’t letit over-fill) and transfer theashes from the pan to alarger, covered metal bucketoutdoors (never indoors);

• use an accessory ash scoopwith a sliding lid to reducethe dust in your home; and

• if you use a shovel andbucket, remove ashes fromthe stove slowly and neverdrop ashes from the shovelinto the bucket. Warm splat-tered ashes are a fire hazard.

Double-bottom ash buckets andash scoops are available fromwood-heating retailers.

Fire ScreenFor safety and performance reasons, you must operate mostwood stoves with their doorsclosed. However, a few stovemodels are safety certified for use with their doors open and aspecial fire screen in place. Thescreen is offered as an optionwith these models. Be aware that stoves operating this wayare less efficient and producemore smoke emissions than theywould with their doors closed. Atany rate, never use a fire screenthat isn’t specifically certified foruse with your stove. Screens usedonly for decoration are no substi-tute for a safely closed stove door.


6 Wood-Heating Accessories

▲Ash bucket

▲Fireplace tool set

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Domestic Hot-Water Coil or TankHeating household tap waterwith a wood stove may seem likean attractive idea, but it is rarelyfeasible because such systems are complicated and expensive.Poorly designed systems can alsobe hazardous. Without properdesign and pressure-relief devices,steam can become trapped andcause a violent explosion. Thehot-water coil or tank must besafety certified for use with yourstove. If you decide to have ahot-water system installed, getadvice from an experienced stoveretailer. Also, make sure that themanufacturer’s instructions forinstalling it are followed exactly.Such coils may also degrade theperformance of a clean-burning,advanced combustion appliance,resulting in high emissions and creosote.

HumidifierDoes the air in your house tendto be dry in winter? Do younotice too much static electricityand have a dry nose and mouth?If so, consider adding humidityto your air. The simplest form of humidifier is a cast-iron pot of water left to evaporate on the stove. Decorative cast-ironhumidifiers designed for thispurpose are available from woodheat retailers. However, youdon’t need humidification if you see any sign of condensationon windows during cold weather.Also, in new, energy-tight houses,problems can arise from too muchmoisture indoors. Experiment tofind the best moisture balancefor your home.


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Support for SafeWood BurningUntil the 1990s, stoves were nottested for safety, and homeown-ers had little or no guidance oninstallation. The result was housefires that were avoidable. Today,after years of co-operative effortsby all levels of government, thewood-heating industry andgroups such as Fire PreventionCanada, several measures are in place to help you heat withwood – safely. These safety measures include the following:

• a reliable installation code(“CSA B365 Installation Codefor Solid-Fuel-BurningAppliances and Equipment”);

• safety-testing standards forstoves, inserts, fireplaces, furnaces, chimneys and fluepipes (almost all equipmentfor sale carries a certificationlabel indicating that it con-forms to safety tests); and

• a thorough training programfor retailers, installers, chim-ney sweeps, municipal fireand building inspectors, andinsurance inspectors (pro-fessionals in every part ofCanada have completed theWETT or APC programs).

Today, wood-heating technologyand its safe installation are morecomplicated. It isn’t safe to sim-ply hook up a wood stove to anexisting chimney and beginusing it for heating. You shouldget reliable advice from a trainedprofessional and consider havingthe wood-burning system profes-sionally installed. This way, youwill get the best performancefrom the system and be assuredof its safety. Before starting theinstallation, get a building per-mit from your municipal officeand inform your insurance agentof your intentions.

The safest and most effectivewood-heating system consists of a high-efficiency stove or fireplace certified by the EPA or CSA B415.1 and a suitable modern, certified venting systemsized to match the appliance.When such a system is installedaccording to the manufacturer’sinstructions and safety codes, it will be as safe as any otherhome-heating option. At first, itwill cost a little more than theolder, out-of-date system. But its higher efficiency and lowermaintenance costs mean yousave every year and get a fasterreturn on your investment.

When installed and used correctly, certified clean-burningappliances significantly reducethe risk of chimney fires. Theiradvanced combustion systemsburn the smoke inside the firebox, so less creosote forms in the chimney. As a bonus, yousave on chimney-cleaning costs,which can be significant for conventional systems that needcleaning two or three times eachheating season.


7 Installation Safety

Look for these symbols as yourassurance of reliable information,advice and services.

The Wood Energy TechnicalTraining (WETT) programis a comprehensive seriesof courses covering instal-lation codes, properinstallation, maintenanceand inspection procedures.

Graduates of the program receivecertificates and wallet cards. WETT-certified retailers can also display theWETT logo in their stores, on their

service vehicles and in advertisingmaterials. When you want reliableinformation, advice or installation ormaintenance services, look for theWETT logo.

Similarly, l’Association desprofessionnels du chauf-fage (APC) is certified to provide the same

assurances in Quebec. Look for the APC logo.

It is worth getting the job done rightthe first time. Your effort will pay off inpeace of mind in the years to come.

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Product Testingand CertificationAgenciesThese three agencies test wood-burning appliances for safety in Canada:

CSA International (formerly the CanadianStandards Association)

Underwriters’ Laboratories of Canada

Intertek Testing Services, Ltd. (formerly WarnockHersey ProfessionalServices Ltd.)

Certified appliances carry a labelwith the logo of the certificationagency. They are your assurancethat the product has been testedand conforms to safety standards.

As part of the certificationprocess, the manufacturer’sinstallation instructions arechecked and approved. Theymust also contain certain basicinformation and messages. You can rely on these certifiedinstallation instructions to beaccurate. When followed, theywill result in a safe installation.Look for these logos when you are shopping for a wood-burning appliance.

Planning a Space HeaterInstallationIf you want your wood-burningspace heater to make a large con-tribution to your home’s totalheating needs, do some planningbefore you select the heater anddecide on its location. Whetheryou choose an advanced combus-tion wood stove, a pellet stove, a high-efficiency fireplace, a fireplace insert or a masonryheater, you should consider the same issues.

Put the Appliance Where You LiveChoosing the right location forthe space heater may be the mostimportant installation decisionyou make. Put the heater in thepart of the house that you want tobe the warmest. This is usually themain floor area – kitchen, livingroom and dining room – wherefamily members spend most oftheir time. By locating the spaceheater here, you will be warm andcomfortable while you eat mealsand relax in the evenings.

Don’t Put the Appliancein the BasementThe basement isn’t usually agood place for space heatingunless you are living there.Although some of the heated air from the stove does rise tohigher levels of the house, itdoesn’t do so effectively. And usually, in an effort to keep themain-floor living spaces warm,the basement becomes over-heated. This wastes fuel, and theconstant high firing can damagethe stove’s internal components.

An unfinished basement withpoorly insulated walls and flooris a particularly bad location fora wood-burning space heater.The walls and floor absorb muchof the heat, which is lost to the outside.

Also, space heaters operating in basements may over-fire orsmoulder without anyone notic-ing. Finally, putting a stove inthe basement can cause ventingand indoor air quality problems.

The basement is a good locationfor a space heater only if yourfamily spends a lot of time in arecreation room there. A base-ment space heater should haveits chimney inside the houseenvelope.


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Balance Stove OutputWith Room SizeThe layout of your house canaffect your choice of an appli-ance. If the house has small andseparate rooms, you probablycan’t heat it well with a singlespace heater. A stove that is toolarge for the room where it isinstalled can make the roomuncomfortably warm. A smallspace heater, however, can supplement your heating needs,while avoiding overheating the area.

Houses of open-plan design withfewer separations between roomsare the easiest to heat effectivelywith a space heater. In this situa-tion, you can use a somewhatlarger appliance without over-heating the space, and the heatcan flow to other rooms.

An experienced wood-burningappliance retailer is often yourbest source of advice on appli-ance sizing for your home. Whenyou visit a store to look over theoptions, take along the blue-prints or a floor plan of yourhouse. This will save time andhelp the salesperson give youbetter advice.

Consider the Chimney LocationThe chimney type, location andarrangement have a lot to dowith how effectively a wood-burning system functions. Whenyou are planning where to putthe space heater, consider whereyou can route the chimney. Ifpossible, avoid running thechimney up the outside wall ofthe house. A chimney alwaysworks best when it runs straightup from the appliance throughthe warm house interior. You can learn more about chimneylocation and performance inChapter 9, “The Chimney.”

Consider HeatDistributionWhether or not a stove or fire-place has an internal fan, theheat from a space heater eventu-ally rises to the ceiling of theroom in which it is located. Heatcollecting at this level tends toflow gradually through openstairwells to higher levels of thehome. If there is no opening, theheat can stay close to the ceiling,while your feet are left cold.

A ceiling fan, slowly circulatingair toward the floor, helpsimprove the overall effectivenessof the space heater. At the sametime, it distributes the heat moreevenly throughout the house.Fans are particularly effective inrooms with cathedral ceilings orin homes without central forced-air heating systems.


CLOSED FLOOR PLAN – Ahouse with many enclosedrooms can be hard to heatwith a single space heater.However, a properly locatedsmall space heater can heatmuch of the house if there is a way to move heat toother areas.

OPEN FLOOR PLAN – A house with an open

design has few walls to separate rooms on the mainfloor. You can usually heatit effectively with a wood-

burning space heater, if youput it in the right place.

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One of the best ways to distrib-ute heat from a wood stove is touse the air-circulating fan of acentral furnace. By running thefurnace fan on low speed, the airis gradually mixed and distrib-uted throughout the house.

If you plan to build a new home,consider having your heatingcontractor install extra cold airreturn grilles on the wall at ceil-ing level in the room with thestove. Since the heated air fromthe stove will rise to the ceiling,the grilles don’t need to be closeto the stove in order to pick upand circulate the heated airaround the house. It is, however,important to balance the flow ofair into and out of the roomthrough the ducts and registers.This way, when the furnace fan

operates, the room will notbecome depressurized; this vacuum-type effect sucks air out of the house, pulling indoorair elsewhere.

In any case, most furnace fansuse a lot of electricity on lowspeed. A better way is buying afurnace with a high-efficiencyelectronically commutated motor (ECM).

Another useful fan is the smallaccessory fan designed to hangin the upper corner of an opendoorway. It helps move heatdown a hallway or into the nextroom. Finally, installing grilles infloors and walls to allow air toflow passively into other roomsor levels helps distribute heatfrom a wood stove.


▲USING A FURNACE FAN TO DISTRIBUTE HEAT – A central furnace fan on low speed slowly circulates the air in the house and distributes the heat from the wood stove to other areas. ▲CAUTION – Never try to use a wood

stove as a central furnace by puttinga hood over the stove and connect-ing a furnace duct to the hood. Thisviolates building codes and disrupts the air-circulating system. It canalso cause the stove to spill smokeby depressurizing the room. Thebiggest danger? The chimney flowcan reverse, filling your house with smoke and posing the risk of asphyxiation while you and your family are sleeping.

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Installing WoodStovesThe guidelines for installing woodstoves can be grouped into twocategories. The first category is forstoves that have been tested andcertified as meeting Canadiansafety standards. The tests deter-mined the lowest clearances andother installation guidelines forthe specific appliance. You canfind this information in the man-ufacturer’s instructions. All newadvanced wood stoves for sale inCanada today have been safetycertified, and most insurancecompanies will accept only certi-fied appliances.

The second category is for appli-ances that haven’t been testedand certified. These include usedor antique stoves, most stovesbuilt before the early 1980s andstoves built by small, informalwelding shops. There are severalgood reasons to avoid uncertifiedappliances.

• They are less efficient thannew, certified appliances, soyou will burn more wood toget the same amount of heat,which will produce high levels of smoke and creosote.

• They require larger installa-tion clearances than newcertified stoves, making themmore difficult and expensiveto install.

• Installation rules for uncerti-fied stoves are so complicatedthat you will need an experi-enced professional to interpretthem or to install your stove.

• The construction quality andconvenience features of newcertified stoves are superiorto older, uncertified stoves.

• Uncertified stoves may con-stitute a serious fire hazard.

• You may not be able to get insurance, even at a high rate.

You can find guidelines forinstalling these uncertified stovesin the solid-fuel-burning installa-tion code, CSA B365. The lowestclearances to combustible materialsfor uncertified stoves are large –1200 mm (48 in.) for radiantstoves and 900 mm (36 in.) forstoves surrounded by jacketsbehind which convection air can flow.


▲ SIDE AND REAR WALL CLEARANCE FOR AN UNCERTIFIED STOVE –The manufacturer’s installation instructions specify the rightclearances for the appliance. The clearances for certified appli-ances vary, but are less than those shown in the followingtable (from CSA B365) for uncertified appliances. Many of the new, certified appliances have heat shields on the sidesand rear, reducing clearances by as much as 90 percent.

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Reduce MinimumClearances SafelyLike most homeowners, youprobably want your wood stoveto take up as little floor space aspossible. As a result, heat shieldsare often used to reduce clear-ances and protect walls andceilings. Some stove manufac-turers offer certified accessoryshields with their products toprovide reduced wall clearance. If you aren’t offered accessoryshields for your stove or if youwant to reduce the clearanceeven further, you can buy effec-tive wall and ceiling shields orhave them built.

You can safely reduce the clear-ances for both certified anduncertified stoves by followingthe rules set out in standardCSA B365. The common featureof the clearance reduction rulesis air space behind the shield material. This space sets up a

convection flow of air when thestove is operating and preventsthe stove’s heat from reachingthe wall. (The percentage shownin the table on page 26 is theamount by which you can reducethe lowest clearance with theparticular shield system listed.)By using heat shields, you canreduce wall and ceiling clearances.

Clearance-reducing shields aremade from various materials,from simple sheet metal to moredecorative brick, stone slices orceramic tiles. Although CSA B365allows you to make shields fromsolid brick, this isn’t practicalbecause they are expensive andhard to build. You can achievethe same visual effect for lessmoney by using brick slices,rather than full bricks. In addi-tion, shields must be permanentlymounted to walls – free-standingpanels aren’t acceptable as clearance-reducing shields.

Rules for constructing heatshields

• Minimum space betweenshield and combustible material: 21 mm ( 7/8 in.).

• Minimum clearance alongbottom of shield: 25 mm (1 in.).

• Maximum clearance alongbottom of shield: 75 mm (3 in.).

• Minimum clearance alongtop of shield at ceiling: 75 mm (3 in.).

• Shield extension beyond each side of appliance: 45 cm (18 in.).

• Shield extension above appliance: 50 cm (20 in.).

• Edge clearance for ceilingshields: 75 mm (3 in.).

• Glues used in shield con-struction must not ignite or lose adhesive qualities at temperatures likely to be reached.

• Mounting hardware mustallow full vertical ventilation.

• Mounting hardware must notbe located closer than 200 mm(8 in.) from the vertical centre line of the appliance.

• Mounting hardware thatextends from the shield sur-face into combustibles maybe used only at the lateralextremities of the shield.


Clearances to Combustible Material for AppliancesUsing Solid FuelSource: CSA International B365-01, Table 2

Minimum clearance, mm (in.)Sides, rear Fuelling and ash

Application Top and corner removal side(s)

Appliances with 1500 (60) 1200 (48) 1200 (48)no shielding*

Appliances with 1500 (60) 900 (36) 1200 (48)shielding*

* Shielding consists of protection such as external jacketing or a metal heatshield attached to the sides and rear of the appliance and spaced out at least50 mm (2 in.) by non-combustible spacers, with provision for air circulation atbottom and top.

Note: Clearances shall be measured from the outer surface of the appliance to the combustible material; a non-combustible covering applied over the combustible material shall be disregarded.

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You can also reduce minimumclearances by using commercialshields. They are tested to deter-mine how effectively they canreduce clearances. The shields arecertified and carry a label thatconfirms they have passed thetests and provides details onclearance reduction. Some com-mercial shields can be attacheddirectly to combustible wallswithout needing an air space.

The first step in reducing clear-ances is to determine the lowestclearance, from either the stovelabel or the Table of Clearancesfor Uncertified Stoves (from theCSA B365 installation code).Then calculate the amount theclearance will be reduced withthe type of shield you plan touse (from the table on clearancereduction).


Reducing Clearances with ShieldingSource: CSA 365-01, Table 3, Reduction in Appliance and Ductwork Clearance from Combustible Material with Specified Forms of Protection

Clearances may be reduced by these percentages

Type of protection (shield) Sides and rear % Top %

Sheet metal, a minimum of 29 gauge in thickness spaced out at least 67 5021 mm (7/8 in.) by non-combustible spacers

Ceramic tiles or equivalent non-combustible material on non-combustible 50 33supports spaced out at least 21 mm (7/8 in.) by non-combustible spacers

Ceramic tiles or equivalent non-combustible material on non-combustible 67 50supports with a minimum of 29 gauge sheet metal backing spaced out at least21 mm (7/8 in.) by non-combustible spacers

Brick spaced out at least 21 mm (7/8 in.) by non-combustible spacers 50 n/a

Brick with a minimum of 29 gauge sheet metal backing spaced out at least 67 n/a21 mm (7/8 in.) by non-combustible spacers

▲CUT-AWAY OF WALL SHIELD ASSEMBLY – By allowing air to flow between theshield and the combustible surface, a wall shielding assembly can safelyreduce minimum clearances. The shield must extend at least 50 cm (20 in.)above the top of the appliance and 45 cm (18 in.) beyond each edge of theappliance.

45 cm(18 in.)

50 cm(20 in.)




wall shield

Page 29: A Guide to Residential Wood Heating

Channel spacers are the mosteffective type because they givegood support to the shield anddon’t transmit heat through the mounting hardware to the combustible wall. Metal wallstrapping, available from mostbuilding supply stores, is made of light steel channels that workwell as shield spacers. Note thatthe bottom of the channel isnotched to allow cooling air toenter. The shield must extend45 cm (18 in.) beyond each edgeof the appliance and 50 cm(20 in.) above the top of theappliance.

Parts of the Wood Stove InstallationA typical wood stove installationconsists of the following compo-nents, starting at floor level:

• a non-combustible floor padto protect flooring or carpetsfrom embers that might fall from the stove duringloading or ash removal;

• a wood stove;

• a flue pipe that connects the flue collar of the stove to the chimney; and

• a chimney system that pro-duces the draft that drawscombustion air into the stoveand expels the exhaust gasesto the outside.

Each part of the space heater system deserves careful attentionduring installation in order toproduce effective heating.

Protect the floorCertified wood stoves will notoverheat a combustible floor.During safety testing, the floortemperature is checked and mustnot exceed safe limits. Althoughthe floor won’t overheat duringnormal operation, you still needto protect it from live embersthat might fall from the stove as you tend the fire or removeashes. The floor pad must be adurable, non-combustible mater-ial, such as sheet metal, groutedceramic tile or mortared brick.Floor pads must normally extendnot less than 45 cm (18 in.) infront of the loading door and20 cm (8 in.) beyond the othersides and the back. Don’t installthe floor pad on a carpet unlessthe pad is struc-turally supported so that it doesn’tmove, crack or distort.

Uncertified stoves haven’t passedsafety tests, so heat from the bot-tom may overheat floors or cause a fire. These appliances have different rules for floor protection,depending on the height of thestove legs and any bottom protec-tion the stove might have. If you are installing an uncertifiedappliance, contact a qualified professional for details. Better yet, choose a new, certified stove –especially a highly efficient model.


▲NON-COMBUSTIBLE FLOOR PAD SIZE AND TYPE – Thefloor pad protects flooring from hot embers or ashesthat might fall from the stove as you fill it or tendthe fire. The pad must extend at least 20 cm (8 in.)beyond the sides and rear, and 45 cm (18 in.) infront of the loading door. Also, the floor pad mustbe a continuous, non-combustible surface. Do notmount the floor pad on carpet, unless the pad isstrong enough to resist bending or cracking.

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Installing flue pipesFlue pipes carry the exhaustgases from the stove flue collarto the base of the chimney. Theyhave been called the weak link in the wood-burning system,because they are often improp-erly installed. As you will seefrom the list below, several rulesexist for safely installing fluepipe assemblies. They apply toflue pipes connected to all wood-burning appliances, includingcentral heating systems.

Flue pipe assemblies should be as short and as direct as possiblebetween the stove and theentrance to the chimney. Thisreduces heat loss and promotes a strong and reliable chimneydraft. The ideal assembly risesstraight up from the stove fluecollar and fits directly into thechimney without elbows orcurves. A straight flue pipeassembly allows the most gasflow and results in a strongerdraft. Straight assemblies alsoneed less maintenance becausethere are no corners where cre-osote deposits can accumulate.

Rules for single-wall fluepipe assemblies

• Minimum clearance fromcombustible material: 45 cm (18 in.).

• The minimum clearance maybe cut in half to 22.5 cm(9 in.) if suitable shielding isinstalled either on the pipeor the combustible surface.

• Maximum overall length ofstraight pipe: 3 m (10 ft.).

• Maximum unsupported horizontal length: 1 m (3 ft.).

• Maximum combined changein direction: 180 degrees (i.e. not more than two 90-degree elbows).

• Minimum upward slopetowards the chimney:2 cm/m (1/4 in. per ft.).

• The crimped ends (male) ofthe sections must be orientedtoward the appliance.

• Each joint in the assemblymust be fastened with at leastthree screws, including theconnections at the applianceflue collar and chimney.

• Flue pipes that are 15, 17.5and 20 cm (6, 7 and 8 in.) indiameter must have at least24 gauge thickness.

• Don’t use galvanized fluepipes – the coatings vaporizeat high temperatures andrelease dangerous gases. Useblack-painted flue pipes.

• The assembly, including theelbows, must have allowancefor expansion: straightassemblies should includeeither an inspection wrapwith one end unfastened or a telescopic section.

Certified double-wall flue pipesystems are also available. Thesesystems are tested to determinethe minimum clearance at whichthey can be installed. You willfind the clearance informationon the labels attached to thepipe and in the manufacturer’sinstallation instructions.



ASSEMBLY – When the flue gas pathis straight, the system produces astronger draft and needs less mainte-nance than an assembly withelbows. The ideal flue pipe assemblyrises straight from the appliance fluecollar into the chimney. A straightsingle-wall flue pipe assembly needsan inspection wrap or telescopic section so that you can install andremove it without having to movethe appliance. The wrap also allowssome movement for expansion when the flue pipe gets hot.

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The lowest clearances forinstalling certified double-wallflue pipes are less than those forsingle-wall pipes. Also, the maxi-mum length of a double-wallpipe assembly may be greaterthan is permitted for a single-wall pipe. This extra length isuseful for installations in roomswith cathedral ceilings, becausethe distance to the base of the chimney may exceed3 m (10 ft.).

The two general types of double-wall flue pipes are sealed andvented. A sealed double-wall flue pipe retains heat in the flue gases because the air spacebetween the inner liner andouter shell acts as an insulator. A sealed pipe is a good choice formost installations, particularly if the assembly must be long or if the appliance is expected to produce low flue gas tempera-tures. These pipes can improvethe draft and reduce creosotedeposits.

Vented double-wall flue pipesrelease more heat into the roomas the gases flow through, byallowing cooling air to passbetween the inner and outer layers, removing heat from theinner surface. This can cause toomuch creosote to form and cre-ate a poor draft. You may need to put the flue pipe a bit closerto a combustible surface.Partially shielded flue pipes,which have a curved shield atthe back towards the wall andexpose the single-wall liner tothe room, are a simple solution.

InstallingAdvancedCombustion,High-EfficiencyFireplacesAdvanced combustion fireplacesare installed within the structureof the house and surrounded bycombustible building materials.The fireplace and its heating flow paths, chimney and othercomponents are safety testedtogether as a unit. Therefore, youcan install only the chimney andthe other components that thefireplace was tested with. Nogeneral instructions exist forinstalling such fireplaces; eachfireplace design has its owninstallation guidelines, whichyou can find in the manufac-turer’s instruction manual.

Once you find an advanced fire-place you like, ask the retailer fora copy of the installation instruc-tions. Study them at home soyou can become familiar withthe fireplace before making yourdecision. The manual will tellyou about safe clearances, mantel heights, limitations ondecorative finishing materialsand guidelines for routing andinstalling remote heating ducts.Spending some time getting toknow the product is worthwhile,even if you plan to hire profes-sional technicians to install thefireplace.


▲DOUBLE-WALL FLUE PIPE ASSEMBLIES –Certified double-wall flue pipes havea stainless-steel inner liner and asealed or ventilated outer shell. Theycost more than single-wall pipes, but last longer and produce a morestable assembly. You can place dou-ble-wall pipes closer to combustiblematerials than single-wall pipes.

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The back of the fireplace and its heating paths and chimneywill be enclosed and out of sight once the installation iscompleted. So it is important to follow the manufacturer’sinstructions exactly to ensurethat clearances are adequate.Installing an advanced factory-built fireplace is complicated andnot a do-it-yourself job – unlessyou have plenty of carpentryexperience and are willing toinvest the time to ensure you get every part of the installationjust right. A better option is tocontract an experienced wood-heat technician to install theunit for you.

InstallingFireplace Insertsand Hearth-Mount StovesOne rule that applies to all fireplace inserts is that a full,stainless-steel chimney liner must be installed from the insertflue collar to the top of thechimney. The liner reduces thesize of the chimney flue tomatch that of the insert collarand isolates the flue gas from themasonry structure. This retainsheat and produces a strongerdraft. The liner also makes clean-ing and servicing easier, since itcan be cleaned from the top ofthe chimney, and the depositscan be removed from inside the insert. With a full liner, youdon’t have to remove the insertfor cleaning, a costly procedurethat can damage the hearth.

A fireplace insert or hearth-mountstove and its full chimney linerare, in effect, permanentlyinstalled. Usually, you must alterthe structure of the masonry fire-place to complete the installation,and it may not be possible toreturn it to its original condition if you change your mind later.

When an insert or hearth mount isinstalled in a fireplace, you almostalways need to extend the hearthat least 45 cm (18 in.) beyond thefront of the appliance to protectthe floor. This hearth extensionmust be permanently mounted tothe floor. Fire-retardant hearthrugs aren’t considered adequatefloor protection. The installationinstructions may also specify aminimum mantel height abovethe insert. If your fireplace mantelis lower, you may need to shieldit so that it doesn’t overheat.

Although installing a fireplaceinsert may appear straightforward,it isn’t a simple do-it-yourself job.Before installation, the existingfireplace and chimney must becleaned thoroughly so that nocombustible deposits remain.Installing the liner can be chal-lenging, and the correct materialsmust be used. The connections to the insert and between linersections must be secure, and allmaterials must be corrosion-resistant. Look for a dealer withyears of experience installinginserts. Professional installersknow the trouble spots and howto avoid future problems.

InstallingMasonry HeatersMasonry heaters are entirely dif-ferent in design, construction andoperation from conventionalmasonry fireplaces. The core ofthe heater, consisting of the fire-box and heat exchanger, has aseries of precast componentsmade of high-temperature brickmaterials. They are assembled by a mason and surrounded bythe finish material (brick, tile or stone). The clearances of amasonry heater from combustiblematerials must meet the standardsfound in building codes for conventional fireplaces.

Someone without specializedtraining and plenty of experiencewould find it difficult to build amasonry heater that would per-form well and last a long time. Amasonry heater is not only costlybut also a lifetime investment, soselect your heater mason care-fully. Ask for references fromprevious customers, and call themfor their comments. Qualifiedheater masons are certified by theMasonry Heater Association ofNorth America.


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Installing Pellet-BurningAppliancesYou can find the installationguidelines for certified pellet-burning appliances in themanufacturer’s instructions. The manual provides details of clearances, the materials used to vent the exhaust and the arrangement of vent components.

Almost all pellet stoves use asmall fan to force the exhaustthrough the venting system, so they do not rely on naturalchimney draft for normal opera-tion. Also, since the fuel and airmixture can be adjusted and setonce the unit is burning cleanly,the fire in a pellet stove is unlikelyto smoulder and produce creosote.For these reasons, pellet stovesdon’t need the high-temperaturechimneys that wood stoves do.Instead, they can use a light-weight double-wall pipe called apellet vent. Some pellet stovescan be vented horizontally outthrough a wall, so you don’tneed a chimney.

However, there are some draw-backs to straight horizontalpellet vent installations. First,the vent must be far from win-dows and doors to keep theexhaust smell from getting intothe house – a location that maybe difficult to find. Second, pelletstove exhaust fans aren’t power-ful. If a strong wind blowsagainst the vent wall, exhaustcan be forced back into thehouse. And third, the stove

may smoke into the house if thepower fails, because there is nonatural draft to draw it outside.

Experienced pellet-stoveinstallers often recommend venting the stove vertically upthrough the roof. At the least,they install some vertical rise, so that you have enough naturaldraft to draw the smoke outsideduring a power failure.

Since the exhaust fan puts pelletstove vents under positive pres-sure, seal each joint carefullywith high-temperature sealant.This will prevent fine ash andsoot particles from leaking intothe room. It is a good idea tohave a new pellet stove profes-sionally installed and adjusted toburn properly. Annual servicingby the dealer to ensure that thesystem is reliable is also a goodinvestment.

Installing CentralHeating Furnacesand BoilersWhen considering central heat-ing with wood, a reputableheating retailer or contractor isyour best source of informationon available systems and theirsuitability for your home. Sinceinstalling central heating appli-ances is complicated and requiresseveral specialized skills, youmust hire professionals to do the work.

Combination wood-oil, wood-electric and add-on furnaces arethe most popular central wood-heating options installed inbasement furnace rooms. Thecontrols and duct systems arelinked, so the heat distributionsystem is shared by both energysources. A certified wood-burningadd-on furnace can share a chim-ney with an oil furnace, providedthe chimney is suited for usewith a wood-burning furnace.However, if coupled with a gasfurnace, the add-on must have aseparate chimney.

All wood-burning furnaces andboilers must be certified to meetthe CSA International safety teststandard. Installation details aredetermined during testing. As aresult, the installation rules foreach make and model of centralheating furnace or boiler differsomewhat. The specific infor-mation can be found in themanufacturer’s installationinstructions.

If you do decide to go with anuncertified outdoor boiler, theinstallation should be done by anexperienced dealer. Get referencesand speak to other owners of out-door boilers before making thedecision and choosing the dealer.With an installed cost as high as$10,000, an outdoor boiler is abig investment. Make sure yourdealer has plenty of experienceand a good reputation.


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Before theSystem IsInstalled• Call your municipal building

department to discuss your plans and find out if youneed a building permit. Insome municipalities, youneed a permit to exchange an old stove for a new one.

• Contact your insurance agentto find out if the installationwill affect your policy. Manyinsurance companies add sur-charges to policies on houseswith wood-burning equip-ment. If you think the quoteis high, shop around – especially if you are having ahigh-efficiency combustionunit installed by a WETT- or APC-certified technician.Some insurance companiesreduce or eliminate surchargesif the system is installed by a certified professional and the appliance is an advancedtechnology model.

• Make sure the installer hasgeneral liability and errorsand omissions insurance.

• Review the installation planswith your retailer, installer or contractor. Make sure youunderstand what is involvedand what all the costs willbe. If you are installing thesystem yourself, get advicefrom a trained professional so that you don’t misinter-pret or overlook any keysafety issues.

• Read the manufacturer’sinstallation instructions carefully.

While the SystemIs Being Installed• Make sure that the manufac-

turer’s instructions are beingfollowed exactly. If theinstaller deviates from theinstructions, ask why. Anyvariation from the installa-tion guidelines should bereviewed by a third partysuch as a building inspector.

After theInstallation Is Completed• Check the installation to

be sure that it meets coderequirements.

• Have your municipal buildingor fire department inspect theinstallation. Some departmentsare reluctant to inspect wood-heating systems. In somecases, these departments willrefer you to a local WETT- orAPC-certified retailer, installeror chimney sweep for theinspection.

• Notify your insurance agent.Your insurance company maysend someone to inspectyour installation.

• Install smoke detectors on ornear the ceiling at the exitsto the room where the appliance is installed. Replacethe batteries annually, and consider installing a carbonmonoxide detector.

• Buy a labelled and approvedABC-type fire extinguisher,and store it near the installa-tion. Follow the instructionson the extinguisher label formaintenance procedures.

• Read and follow the manufacturer’s operatinginstructions.


8 Your Installation Checklist

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How ChimneysWorkAn effective chimney is an impor-tant part of any successfulwood-burning system. Many ofthe reported problems with theperformance of wood-burningappliances can be traced to thechimney. Knowing how chimneyswork is not only necessary inselecting the correct type anddesigning the installation, but alsouseful in operating your wood-burning system from day to day.

Chimneys operate on the princi-ple that hot air rises above coldair – thus, the hot gas in a chim-ney rises because it is less densethan the air outside the house.The rising gas creates a pressuredifference called draft, which

draws combustion air into theappliance and expels the exhaustgas outside through the chimney.The hotter the gas comparedwith the air outside, the strongerthe draft. In this chapter, youwill also learn that a chimneyshould produce a small amountof draft even when no fire isburning. In fact, some of themost serious flaws in chimneyperformance are revealed whenthe appliance is not being used.

The chimney’s function is to produce the draft that drawscombustion air into the appli-ance and safely exhaust the gasesfrom combustion to the outside.To fulfil this role, the chimneymust do the following:

• isolate nearby combustiblematerials from flue gas heat;

• tolerate the high gas temper-atures caused by overfiringand chimney fires;

• conserve flue gas heat to produce a strong and consistent draft;

• resist corrosion and weathereffects; and

• be well sealed to preventleakage.

Guidelines for InstallingChimneys 1) Install the chimney within the

house envelope, rather than up an outside wall. Chimneysalong an outside wall areexposed to wind and low tem-peratures; this chilling effectcan reduce the available draftto the appliance and causecondensation. Outside chim-neys also tend to create a cold backdraft when no fire isburning. This allows cold airand odours to enter the houseand makes it hard to light afire without getting smoke inthe house. On the other hand,chimneys that run up insidethe house benefit from beingenclosed within a warm envi-ronment. Inside chimneysproduce stronger draft andaccumulate less creosote whena fire is burning. They usuallyproduce a small amount ofdraft, even when there is no fire.

2) Building codes require that the top of the chimneyextends at least 1 m (3 ft.)above the point where it exitsthe roof. It should also be at


THE ROOF – The top of a chimneyshould be high enough to beabove the air turbulence causedwhen wind blows against thehouse and its roof. The chimneymust extend at least 1 m (3 ft.)above the highest point of con-tact with the roof, and at least60 cm (2 ft.) higher than anyroof line or obstacle within a hori-zontal distance of 3 m (10 ft.).

Modern, efficient appliances needmodern, efficient chimneys. Theselection, location and installa-tion of the chimney are asimportant as the type of wood-burning appliance you choose. Aproperly designed and installedchimney will provide many yearsof reliable service and allow yourappliance to perform correctly.


9 The Chimney

60 cm (2 ft.) minimum

3 m (10 ft.)

1 m (3 ft.) minimum

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least 60 cm (2 ft.) higher thanany roof, building or otherobstacle within a horizontaldistance of 3 m (10 ft.). Theserules are intended to place thetop of the chimney higherthan any areas of air turbulencecaused by wind. In practice,chimneys must sometimes beraised even higher than theseminimums in order to avoidair turbulence caused bynearby obstacles, such as treesor other houses.

3) The most important factor inchimney draft is temperaturedifference. If you experiencedraft problems, increase fluegas temperature by doing oneor more of the following:

• burn smaller, hotter firesto avoid smouldering;

• keep the flue pipe assem-bly as short and straight aspossible (try not to useright angles);

• use a sealed double-wall flue pipe;

• re-line a masonry chimney;

• re-install the chimneyinside the house; or

• construct an enclosure orchase around an outsidechimney.

4) The chimney flue should bethe same size as the applianceflue collar. In the past, manychimneys were too large forthe appliance they served. Butbigger is not better when itcomes to chimney size. Fluegas flows faster and has lesstime to lose heat in a smallerchimney flue. In planning

wood-heating systems, someexperienced installers evenchoose a chimney that has asmaller inside diameter thanthe appliance flue collar. Theyusually do this when thechimney runs inside the houseand is fairly tall. Chimneystaller than 8 m (about 26 ft.)sometimes produce more draftthan the appliance needs, so a smaller-diameter chimneydoesn’t reduce performance.Only an experienced techni-cian should decide whetherthe flue should be smallerthan the appliance flue collar.

5) Taller chimneys producestronger draft. A rule ofthumb is that the entire sys-tem (from the floor on whichthe appliance is mounted tothe top of the chimney) mustbe at least 4.6 m (15 ft.) high.Most installations are tallerthan this, but those in cot-tages with shallow-pitchroofs or in single-storeybuildings with flat roofs maynot. If you experience draftproblems with a short sys-tem, consider adding to thechimney’s height. However, if your chimney runs up theoutside wall of the house,making it taller may notimprove draft, because theextra heat loss cancels outany benefit.

Suitable ChimneyOptionsTwo general categories of chim-neys are approved for use withwood-burning appliances: the650°C factory-built chimney and the masonry chimney.

The 650°C Factory-Built Chimney

Specific types of factory-builtmetal chimneys can be used withwood-burning appliances. Woodstoves, wood-burning centralheating furnaces and some fac-tory-built fireplaces must use the650°C metal chimney, approvedto Underwriters’ Laboratories ofCanada (ULC) standard S629.The 650°C refers to the continu-ous gas temperature for which itis designed; it is higher than forchimneys intended for otherfuels. Most, but not all, 650°Cchimneys have 5 cm (2 in.) ofinsulation between the innerliner and outer shell.

The 650°C chimneys were devel-oped in the early 1980s becauseearlier chimney designs couldn’twithstand the heat from a

This type of chimney was devel-oped to withstand the hightemperatures produced by achimney fire. It features betterinsulation than other factory-built chimneys to isolate nearbycombustible material from thehigh gas temperatures in theflue when a fire is burning. Atthe same time, this increasedinsulation keeps flue gases andinner flue surfaces warmer. As aresult, less creosote forms in thechimney, reducing the risk ofchimney fire significantly.


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chimney fire. The 650°C chim-ney has better insulation and astronger, more corrosion-resis-tant inner liner than the oldertypes. This improved insulationisolates nearby combustiblematerials from high gas tempera-tures in the flue. The insulationalso makes a chimney fire lesslikely to occur. By keeping fluegases warmer, less creosote formsin the chimney.

Most new factory-built fireplacesare approved for use with a spe-cial metal chimney that has a25 mm (1 in.) wall thickness, but has the same upgraded linerfound in the 650°C type. Yourwood-heating retailer can showyou the differences betweenthese chimney types and whichone you will need. All factory-built chimneys must have theproper chimney cap installed toproduce reliable draft, to preventwater from leaking in and tocomply with the manufacturer’sinstallation instructions.

The Masonry ChimneyA conventional masonry chim-ney consists of a clay tile linersurrounded by a structure ofbrick, block or stone. Stainless-steel liners can be installed inmasonry chimneys to correctinternal damage caused by achimney fire. A qualified chim-ney sweep should inspect yourexisting masonry chimney beforeyour wood-burning appliance isinstalled.

Masonry chimneys that are built according to the guidelinesfound in all building codes maybe used with wood-burningappliances. If you are planningto have a masonry chimneybuilt, get a building permit. Andmake it clear to the mason whowill be doing the work that thechimney must conform to thebuilding code.

Your masonry chimney will per-form better if you build it withnew materials rather than tradi-tional ones. For example, youmay wish to specify round fluetiles instead of the standardsquare or rectangular tiles. Roundclay flue tiles with shiplap jointsare also available. These jointsgive a better fit and help preventsmoke and moisture from leakinginto the surrounding masonry.Alternatively, some brands of certified stainless-steel chimneyliners are now approved for use in new chimney construction.Specialized, poured-in-place chimney liners are also availablein some areas. A local chimneysweep can tell you if there is acontractor near you.


▲Factory-built chimney

▲Masonry chimney

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One important feature oftenmissing from masonry chimneysis a proper rain cap. The namemay imply that it just keeps rain out of the flue, but it hasanother key role – it helps pre-vent smoking and other draftproblems caused by the wind.When wind flows down towardthe open top of a chimney, itproduces a positive pressurezone. This works against chim-ney draft and forces the exhaustback down the chimney. Evenwhen wind flows horizontallytoward a chimney, its normalturbulence can produce pressurethat opposes or increases chimney draft. Every chimney,regardless of its design or materi-als, should have a cap to reducewind-related venting failures ordisruptions.

To have your existing masonrychimney checked, your bestoption is to hire a qualifiedchimney sweep. If you see anydeterioration of the bricks ormortar joints near the top of thechimney, dark stains or whitedeposits on the brick work,pieces of tile or liquid stains atthe chimney clean-out, or brickfaces splitting off outside, havethe chimney inspected andrepaired immediately.

Masonry chimneys that havebeen damaged by a chimney fire,or that are too large for yourappliance, can be re-lined with acertified, stainless-steel liner. Theliner can have either a rigid orcorrugated flex design.

UnsuitableChimneysType A Chimneys – This type of metal chimney, used before1983, is not suitable or accept-able for wood-burning appliancesunder building code guidelines.This chimney was designed foroil furnaces, which is how it ismainly used today. Type A chim-neys cannot withstand the hightemperatures of chimney fires.

Type A chimneys normally had a25 mm (1 in.) wall thickness andwere available with either roundor square outer casings. If yourwood-burning system uses a Type Achimney, consider upgrading to the new 650°C chimney assoon as possible. If it cannot bechanged right away, have yourchimney cleaned and inspectedby a certified chimney sweep todetermine if it is still safe to use.Deteriorated metal chimneys canbe hazardous.

Bracket Masonry Chimneys –The term “bracket chimney”refers to masonry chimneys thatrest on wooden or brick supportswithin the wall of a house, ratherthan being supported on properconcrete foundations. Don’t use bracket chimneys. They are potentially hazardous andcannot be upgraded to meetbuilding code requirements. Tocomply with the codes, masonrychimneys need a foundation that extends below the frost line, which is a few metres below grade in most of Canada.

Unlined Masonry Chimneys –Masonry chimneys must have aliner made of clay tiles, firebrickor stainless steel to be suitable.You can upgrade some old,unlined chimneys by installing a certified stainless-steel liner.

Air-Cooled Chimneys – Somedecorative factory-built fireplacesare approved for use with chim-neys that use air flow, instead ofsolid insulation between innerand outer layers, to keep theouter surface cool. Never connectwood-burning heating appliancesto air-cooled chimneys, or fluegas will cool excessively.


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Creosote andChimney FiresWhen wood burns slowly – as itoften does in a conventional, air-tight stove or furnace – it makes a smoky fire and produces morecreosote deposits than a quick,hot fire does. Creosote is a highlyflammable material. If it ignitesnear the base of the chimney, itcan produce a raging fire thattravels up the chimney, creatingextremely high temperatures as itspreads. The high temperaturecan damage the clay liners in amasonry chimney or the metalliner in a factory-built chimney.Although 650°C chimneys canwithstand these temperatures,the heat causes extreme stress inthe chimney.

Chimney fires result from poorfiring techniques combined witha lack of maintenance. If unsea-soned wood (wood that hasn’tbeen dried enough) is burnedslowly in an old “airtight” heater,creosote can build up quickly and the risk of a chimney fireincreases.

When you operate wood-burningappliances properly, some cre-osote may still be deposited, but it will be less combustible.Instead of the black, tarry, highlyflammable creosote from smoul-dering fires, proper firing maycreate small amounts of soft,flaky and dark brown deposits.

You can prevent chimney fires.Have your chimney checked for creosote deposits regularly,until you find out how quickly it builds up in the system.Conventional wood heaters canproduce creosote quickly becausethey can’t burn the wood as com-pletely as advanced combustiondesigns. In severe cases of smoul-dering, it may take only a fewdays for enough creosote to buildup to sustain a chimney fire. Thenew, low-emission wood stovesburn the wood so completelythat, when operated properly,their chimneys normally needcleaning only once a year.

Never assume that the chimneyis clean. Check it regularly to besure, especially during the springand fall. If you do have a chimneyfire, have the chimney inspectedand repaired, if necessary, beforeusing the system again. A chim-ney fire is a clear sign of a problemwith the appliance, the fuel or theway the system is operated. Makechanges to avoid chimney fires inthe future.

Using an energy-efficient wood-burning appliance, coupled withgood installation and properburning techniques, dramati-cally lowers the chance of achimney fire.


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The smell of wood smoke insideyour home is a sign that thewood-burning system isn’t work-ing properly. Smoke containsharmful air pollutants, whichcan be irritating or even danger-ous in high concentrations.Wood-burning systems that areproperly designed, installed andoperated will not spill smokeinto the house. If you have beenusing proper burning techniques,burning only dry wood, and stillsmell smoke in your home, haveyour system inspected.

Three ReasonsWhy Smoke SpillsFrom Wood-Burning SystemsPoor System DesignCertain design characteristics can make a wood-burning systemmore likely to spill smoke. Mostof them result in low flue tem-peratures and low draft. Forexample, chimneys that run upthe outside wall of the house lose heat and produce weakdraft. Long, single-walled fluepipe assemblies give up toomuch heat before the gases evenreach the chimney. Each 90°elbow in the flue pipe assemblyrestricts and slows down the flowof gases. More than one elbowcan restrict the flow enough tocause smoke spillage. Any ofthese characteristics may or maynot cause smoke spillage on itsown. However, when an outsidechimney is combined with along flue pipe assembly with several elbows, you will almostcertainly have smoke spillage.

Negative Pressure in the HouseEnergy efficiency practices andnew building codes are makingnew houses more and more airtight. The reduced air leakagemakes houses more comfortableand easier to heat. But it can create problems if you use high-volume exhausts. For example, a powerful downdraft kitchen-range exhaust can force more air out of a new house than what leaks in through its tightlysealed walls.

Appliances such as high-gradebathroom or kitchen fans,clothes dryers and central vac-uum cleaners can cause similarproblems. When this happens,the pressure inside the housebecomes negative compared tothe outside, which works againstchimney draft. In severe cases,this pressure draws smoke backdown the chimney into thehouse. This reverse flow is mostlikely to happen as the fire diesdown to a coal bed, when chim-ney draft is weakest.

You can avoid negative pressureproblems in your new home bylimiting the number, size and useof exhaust fans. Avoid runningpowerful fans such as a down-draft range exhaust while thewood-burning system is operat-ing. If you can’t avoid using thefan, link the exhaust system to a make-up fan that forces air into the house to replace theexhausted air. This keeps thehouse pressure close to neutral.Contact your wood-heatingretailer or heating contractor fordetails on make-up air systems.

Building codes cover the poten-tial for excessive depressurizationof airtight new houses. Twooptions are normally permittedto ensure good indoor air quality:

• installing a make-up air sys-tem to compensate for the airexhausted from the house; or

• installing a carbon monoxidedetector in the room con-taining the wood-burning system to detect and warn of spillage.

Your wood-heating retailer ormunicipal building departmentcan explain the local rules.

Improper Appliance-Firing TechniqueOne of the most common reasons for smoke spillage is asmouldering fire. A wood firethat is starved for air will smoul-der, and the exhaust temperaturewill fall too low to produceenough draft. If you open theloading door during a smoulder-ing fire, smoke will spill into theroom. Even when the loadingdoor is closed, severe smoulder-ing can produce smoke spillage,which can be hazardous when ithappens during the night. Byusing the suggestions on properfiring techniques found inChapter 12, “Burning WoodEfficiently,” you will be able tobuild effective fires and preventsmouldering.


10 Preventing Smoke, Smells and Cold Hearths

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Does Outdoor Air ReduceSmoke Spillage?It has been widely believed thatyou could reduce or eliminatesmoke spillage by supplying out-door air through a duct, eitherdirectly to the appliance’s com-bustion chamber or indirectly tothe room in which the applianceis located. However, researchshows that outdoor air suppliesmay not work. Smoke spillageoccurs at the same level of roomdepressurization, whether or notan outdoor air duct is installed.The same research shows thatwind effects around the house canreverse the flow in these ducts,which may create a fire hazard ifthe duct is connected directly tothe combustion chamber.

Some building codes require thatyou provide wood-burning fire-places with outdoor combustionair. You must comply with thisrequirement, but be aware thatperformance will not improve.And take steps to protect com-bustible materials around theduct from overheating if the gasflow reverses.

Is Your HouseActing Like aChimney?An operating chimney is anenclosed column of warm air orgases surrounded by colder out-side air. The warm air or gas inthe chimney is more buoyantthan the dense, cold outside airso it rises. This produces thedraft in the chimney.

In winter, your house is also anenclosed column of warm, buoy-ant air creating a form of draft. Ineffect, the warm air creates higherair pressures as it pushes towardthe top of the house. At the sametime, the pressure in the base-ment is lower than the pressureoutside. This is why the basementof a leaky house feels drafty andthe rooms on the second floor aremore comfortable – the cold out-side air is drawn into the area oflower pressure. The difference inpressure at various levels of thehouse is called stack effect. Itcan cause venting problems andsmoke spillage when it competeswith a chimney that serves awood-burning appliance in thebasement.

Some houses act more like chimneys than others. Two- orthree-storey houses produce moreof a stack effect than bungalowsbecause they have a taller columnof warm air. A house with most of its leaks or open windows atthe upper levels tends to producemore of a stack effect because theleaks offer a ready path for warmair to escape (like the open top ofa chimney). Outside chimneysconnected to heating appliancesin the basement can backdraft ifthe stack effect is strong enough.This allows cold outside air – orsmoke and/or carbon monoxide ifthere is a smouldering fire in theappliance – to spill into the house.

The stack effect is particularlytroublesome when an applianceserved by an outside chimney is installed in a single-storey section of a two-storey house (as shown in the illustrationbelow). When no fire is burningin the stove, the chimney can’tproduce as much standby draftas the house produces in thestack effect because the chimneyis shorter and colder.


PROBLEM INSTALLATION – The wood stove in this house willlikely cause problems. Note that the chimney top is lower

than the ceiling of the second storey – meaning that thehouse is a more effective stack than the chimney. Fires

will be difficult to light because the system will produce aweak draft until the chimney is thoroughly warmed.

Smoke may spill from the stove door when it is opened for loading wood. And there will be some risk of smoke

spillage as the fire dies down to a coal bed.

You could improve this installation by moving the appliance and chimney to the wall that is next to

the two-storey section of the house. The chimney would runinside the house and be protected from the cold. You could

also make it tall enough to clear the roof of the taller sectionof the house (without it being unsightly). However, it might

lose a lot of heat if it is too exposed, resulting in flue gas con-densation, perhaps creosote deposits, along with a poor draft.

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You can expect chimney draftand smoking problems if thewood-burning stove or fireplacein the basement is installed withan outside chimney. Avoid thisform of installation, if possible.

Chimneys that run up throughthe house and exit at or near theroof peak can overcome the stackeffect because they always pro-duce a stronger draft than thehouse’s stack effect. Stack effectis always present in houses, butyou can minimize its influenceby installing the chimney insidethe house and placing it where it can penetrate the roof near the peak.

The Cold-Backdraft-at-StandbySyndromeIf you heat with wood, you mayhave experienced this situation:You go to the basement to builda fire in the wood stove. Whenyou open the door to put in thenewspaper and kindling, you aregreeted by a blast of cold air.Then you light the kindling andthe smoke comes into the roominstead of going up the chimney.

This is the “cold-backdraft-at-standby” syndrome. Negativepressure in the house producedby operating a powerful fan like a kitchen exhaust fan can causethis reverse flow. Most often, itcomes from the combined effectof an outside chimney and a base-ment location for an appliance.

Here’s how it works. When thereis no fire in the appliance, the airin the chimney cools to the out-side temperature. The chimneyproduces no draft whatsoever.The slight negative pressure inthe basement, caused by thehouse’s stack effect, is enough to pull the cold air down thechimney and out through anyopenings in the stove.

Homeowners with installationsthat are susceptible to the syn-drome have found ways to getthe fire started. For example,they open a window on the samelevel, on the windward side ofthe house to relieve the negativepressure. Then they light somenewspaper in the base of thechimney to get enough heat intothe flue to produce some draft.But this and other techniquesonly mask the problem; theydon’t correct it.

To ensure that you never experience the cold-backdraft-at-standby syndrome, don’t combine an outside chimneywith a basement stove. Instead,install the stove on the mainfloor where you spend most ofyour waking hours, and use aninside chimney.


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Maintaining your wood-burningsystem ranges from simple, fre-quent tasks such as removingand disposing of ashes to more complicated jobs such as replac-ing parts that have worn fromusage and heat stress. Regularupkeep also helps the systemoperate efficiently and safely,since one of the most importantmaintenance tasks is removingcombustible deposits from theflue pipe and chimney.

Wood-burning systems operateunder a variety of conditions dur-ing each heating season, whichcreates the need for many main-tenance tasks. In the spring andfall, heat demand is relativelylow. So slow burning may causecreosote to build up in the fluepipe and chimney more rapidly.This is a common problem withconventional wood-burningstoves that can’t burn at low heatoutputs without smouldering.

During the colder months, wood-burning systems operate closer totheir maximum heat output forlong periods, creating stress oninternal components. Manymodern wood heaters have inter-nal components, includingbaffles and catalytic combustors,that wear out from exposure tohigh temperatures. Replace thesecomponents when necessary.

One of the best ways to ensurethat your wood-heating system is safe, clean and effective is tohire a trained, insured and certi-fied chimney sweep to conduct a thorough maintenance checkeach year. Professional chimneysweeps will clean the entire system and report any problems.They might suggest that it is

time to replace the flue pipes,baffles, catalytic combustor (ifyou have one) or door gaskets –and may even be able to do thework for you when the timecomes. Your wood-heatingretailer may also offer sweepingand maintenance services.

Summer is a good time to sched-ule maintenance, before youlight the first autumn fire. It can also be done in the spring,following the winter wood-heating season.

ImportantMaintenanceTasksHere are the most importantmaintenance tasks to consider as you look over your wood-heating system.

Clean and Inspect theChimney and Flue Pipes Check the chimney and fluepipes regularly until you deter-mine the rate of creosotebuildup. Chimney fires usuallyoccur because users don’t knowhow quickly the deposits developand neglect to clean them.Check often and clean off thecreosote when it is visible andclinging to the liner surface. Dry,flaky deposits are less dangerousthan black, shiny creosote. Olderor smouldering systems mayneed cleaning as often as everythree weeks.

During a maintenance inspec-tion, check the chimney and fluepipes for signs of deterioration.Check the flue pipes for corro-sion that can weaken the joints.Look for corrosion or rust stains

on the outer shell of a metalchimney, and check for bulges or corrosion in its inner liner.

When inspecting a masonrychimney, look for black or whitestains on the outer bricks andcracks. Look for missing pieces in the chimney liner as well.Locate the clean-out door for thechimney – it is usually in thebasement, below the point wherethe flue pipe enters the chimney(however, in some installations,it is outside the house). Open theclean-out door at the base of the chimney and check for tile fragments and liquid stains.Remove any deposits. Make sure the door is tightly sealedafterwards.

Check the condition of thechimney in hidden spaces –including the attic, wall andchimney chase areas – where corrosion and other deteriorationcan occur. Do the most thoroughcleaning and inspection of thesystem in the spring, just afterthe heating season is over. Anydeposits left in the system, combined with warm, humidsummer air, may corrode thesteel parts. Cleaning and inspect-ing the system in the spring alsogives you time to order replace-ment parts and do any repairsbefore the heating season beginsin the fall. If you see any prob-lems during your cleaning andinspection and aren’t sure howto handle them, have a qualifiedtechnician inspect and repair thesystem before you use it again.


11 Maintaining Your Wood-Heating System

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Adjust Door TensionMany modern wood heaters haveadjustment screws on their load-ing doors. They are designed tokeep tension on the door gasketto prevent smoke leakage. Theseadjustments are usually simpleand keep the heater working.Adjust the door, for example,when you see a haze of soot onpart of the door glass. You will be able to tell where the leak isfrom the shape of these streaksof haze.

Replace Door Gaskets and Other SealsAppliance designers use gasketsto prevent unwanted air fromentering the firebox. Leaky gas-kets reduce efficiency and maydisable the combustion system of an advanced wood burner.Gaskets are located around theloading door, the glass panel andmost ash-pan openings. You mayneed to replace some gaskets asoften as once a year; others maybe fine after several years of use.Check all gaskets at least once a year during a thorough mainte-nance inspection and occasionallyduring the heating season.

Check and ReplaceCatalytic Combustors If you have a catalytic stove, youcan test the catalytic element’sfunction by watching the smokeas it exits the chimney top. Witha well-established fire burning,open the bypass damper andobserve the top of the chimney –you will likely see some smoke.Then close the bypass damper,wait 10 minutes and check the

chimney top again. If you stillsee smoke, remove the catalyticelement and check it.

Examine the catalytic combustorand its mount during your main-tenance checks. The combustor is fragile, so use a clean, softpaintbrush to remove ash dust.You may see cracks in the honey-comb of the catalyst, but theywill not necessarily affect opera-tion. If pieces are missing, replacethe catalyst. A leaking bypassdamper seal can dramaticallyincrease emissions from a catalytic stove. Therefore, makesure you check the bypass gasket.

The catalyst in a high-efficiencywood stove is certified by theEPA or CSA B415.1 and is usually guaranteed for up to sixyears. Under heavy use, however,it may last only one to two years. If in doubt about when to replace these parts, ask your hearth products retailer.

Examine Baffle PlatesComponents inside the combustion area of advancedwood-burning stoves and fire-places are exposed to extremelyhigh temperatures and may dete-riorate with use. Internal bafflesmay last as long as 10 years or as little as two, depending on the design and on how you usethe appliance.

Internal air channels and tubesmay become disconnected oreven fall into the firebox. Correctany such change to your stoveimmediately because perfor-mance will suffer and otherinternal components will likelybe damaged.

Maintain Door GlassThe glass door in a modernwood-burner isn’t glass at all, buta transparent ceramic materialthat can withstand very hightemperatures. It is unlikely thatthe “glass” will break because ofheat, but it could be damaged ifstruck with a hard object. If youneed replacement glass, visit thestore where you bought yourstove or fireplace to get the rightsize, shape and material.

The door glass will need cleaningperiodically – wait until theappliance has cooled beforecleaning. A damp cloth or papertowel should remove any ashdust or light brown stains. Fordarker, more stubborn stains, buy special stove glass cleanerthat will not scratch the surface.Check the special gasket aroundthe glass and replace it when itgets worn or leaky.

Many of the new, high-efficiencystoves feature a forced-air mecha-nism that helps to keep the doorglass clean.


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Owners must learn and practisethe skills needed to operate theirwood-burning system effectively.By mastering the techniquesoffered here, you will

• reduce the amount of woodyou need to burn to heatyour home;

• reduce outdoor and indoorair pollution from woodsmoke;

• reduce the frequency ofchimney cleaning; and

• increase the convenience andpleasure of wood burning.

The Basics: WhatHappens WhenWood BurnsAs firewood burns, it goesthrough three phases.

Boiling off the water – Up tohalf the weight of a freshly cutlog is water. After proper season-ing, the water content is reducedto about 20 percent. As the woodis heated in the firebox, thiswater boils off, consuming heatenergy in the process. The wetterthe wood, the more heat energyis used to boil the water. That iswhy wet firewood hisses and sizzles and is hard to burn, while seasoned wood ignites and burns easily.

The emission of smoke – As thewood heats up and passes theboiling point of water, it starts tosmoke. The smoke is the visibleresult of the solid wood decom-posing as it vaporizes into acloud of combustible gases andtars. If the temperature is highenough and oxygen is present,the smoke will burn. When it

does, it produces the brightflames that are characteristic ofwood combustion. If the smokedoesn’t burn in the firebox, itexits the appliance into the fluepipe and chimney. Here it eithercondenses – forming creosotedeposits – or is expelled as airpollution. Unburned smoke alsorepresents a less efficient appli-ance because smoke containsmuch of the wood’s total energy.Advanced combustion systemsare designed to burn the smokebefore it leaves the stove, whichis one reason they are more efficient than older models.

The charcoal phase – After thewater has boiled off and most ofthe gases and tars have vaporizedout of the wood, charcoalremains. Charcoal is almost 100-percent carbon. It burnswith a red glow and some flameor smoke when enough oxygenis present. Charcoal is a goodfuel that burns easily. However, burning charcoal often producescarbon monoxide, a seriousindoor air pollutant.

By firing your wood-burning system correctly, you improve effi-ciency and reduce air pollution.


12 Burning Wood Efficiently

▲PHASE 1Evaporation of water

▲PHASE 2Emission of smoke

▲PHASE 3Charcoal

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In practice, all three phases ofwood combustion usually occurat the same time. The wood gasescan flame and the edges of thepieces can glow red as charcoalburns, while water in the core ofthe piece is still evaporating. Thechallenge in burning wood effec-tively is to boil off the water inthe wood quickly, while makingsure the smoke burns with brightflames before it leaves the firebox.

With the new, advanced combus-tion designs, two flame zones areoften visible: the primary flamethat rises from the wood and thetransparent secondary flame thatswirls above the wood. Once agood fire is established and youturn down the air control, youcan see the primary flames slowdown and become smaller. To geta clean, efficient burn, make surethat there is always a secondaryflame. A welcome feature ofthese advanced wood-burningdesigns is that the better thecombustion and the cleaner theburn, the more interesting theflame looks.

Starting a FireYou need the following ingredi-ents to build and maintain agood wood fire:

• a properly designed andinstalled wood-burning system;

• newspapers (do not usecoloured or coated paper);

• dry, finely split kindling in a variety of sizes; and

• dry cord firewood split into a range of sizes.

The first step in building a fire isto find out where the combus-tion air enters the firebox. Inmost advanced stoves and fire-places, some air enters thefirebox through a narrow stripabove and behind the glasspanel. This air wash flows downacross the glass to the front ofthe fire. (It flows downwardbecause it is cooler and heavierthan the combustion gases.)Most models also have the primary air inlet near the bottomfront of the firebox, usually justinside and below the loadingdoor. This is where you light thefire, so that it gets plenty of air.

Next, crumple fouror five sheets ofnewspaper and putthem in the fire-box. You may needmore newspaper ifyour firebox islarge or your kin-dling isn’t dry orfinely split. Manypeople make themistake of usingtoo little newspaper– be generous andyou will have moresuccess.

Hold the paperdown with

10 to 15 pieces of dry kindling.Softwoods, such as cedar andpine, make good kindling (ofcourse, use the species availablein your region). Place the kindling on and behind thenewspaper, so that the combus-tion air reaches the newspaperfirst where you light it. It is alsoa good idea to add one or twosmall pieces of dry firewood tothe kindling load before lighting.

Open the air control fully, lightthe newspaper and close (butdon’t latch) the door. When thepaper is flaming brightly and thekindling catches, latch the door.Some appliances have morerestrictive air supplies than others, so you may have to leave the door ajar for as long as15 minutes – until there is a hotkindling fire and the chimney is producing strong draft. Sinceleaving the door unlatched oropen even slightly for extendedperiods may cause dangerously


▲ TO BUILD A KINDLING FIRE – Useplenty of crumpled newspaper anddry, finely split kindling. Never useglossy paper or coloured advertisingflyers. Open the air control fully.Light the newspaper near where thecombustion air enters the firebox.When a kindling fire is built properly, you should expect rapidignition with no smouldering. Never use liquids to start a fire.

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high temperatures, NEVER leavethe stove unattended in this condition.

When starting a wood fire, yourgoal is to light it once and makesure the fuel ignites rapidly.Practise this procedure a fewtimes – you might be surprised athow quickly you can establish ahot, bright fire. When the flamesfrom the kindling load begin tosubside, gradually add severalsmall pieces of wood. Avoidsmothering the fire with the newwood. Place the pieces on andbehind the burning kindling.

NoteThe suggestions offered here are general and apply to manywood-burning appliances. However,some combustion designs – notablysome of the new advanced combus-tion stoves, catalytic systems andmasonry heaters – may require special firing techniques. In thiscase, you should follow any detailedfiring instructions in the operator’smanual that came with your stoveor fireplace.

An Alternative –Building a Top-Down FireYou may find it convenient to build a wood fire using thetop-down method. To build a top-down fire, reverse the proceduredescribed in the “Starting a Fire”section above – that is, place twoor three firewood pieces at theback of the firebox and lean 10 to15 pieces of kindling against thelogs. Then place several crumpledsheets of newspaper on andaround the kindling. Open the air control fully, light the news-

paper and close the loading door.The fire will start reliably andprogress to the large pieces ofwood without any further pokingor adjustment.

There are several advantages to the top-down fire buildingmethod:

• there is less visible start-upsmoke at the top of thechimney;

• there is little chance that thefire will collapse and smotheritself; and

• you do not need to open theloading door to add largerpieces once you establish thekindling fire.

The top-down fire techniqueisn’t appropriate for every typeof wood-burning appliance, butit can be effective in some cases.

Rekindling a Firefrom CharcoalIn many wood-burning stovesand fireplaces, there will be livecoals toward the back of the fire-box, furthest from the air supply,after the fire has burned down.To rekindle them, first removethe ashes from the front of thefirebox, then rake the live coalsforward until they are just insidethe loading door. If only a smallamount of charcoal remains, youwill have to start with kindling.If you have a good quantity ofglowing charcoal to work with,place the new load of firewoodon and behind the charcoal.Open the air inlets fully andclose the door.

With some of the new, high-efficiency combustion stoves, you have to alter the procedureslightly. Read the manufacturer’sinstructions and experiment a little. For example, some designsrequire you to make a channelthrough the ash pit from front to back, underneath the wood.

Once you have added new woodto the charcoal, expect it toignite almost instantly. The bottom pieces may even startflaming before you get the doorclosed. Allow the fire to burnwith bright, turbulent flamesuntil the wood is charred. Thisusually takes between 10 and20 minutes, depending on thesize of the pieces and the mois-ture content of the wood.


▲TO REKINDLE A FIRE FROM HOT COALS –Rake the charcoal toward the frontof the stove where the combustionair enters. Place the pieces of woodon and behind the coals. Open theair inlet fully and leave it open untilthe wood pieces are well charred.This illustration shows how piecesare arranged for an extended fire.

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When the wood is charred, grad-ually reduce the air setting toproduce the amount of heat andlength of burn you desire. Youmay want to try reducing the aircontrol setting in two or threestages. The result will be lesssmoke because the fire won’thave to recover from a single,large reduction in air supply.

Remember the most importantrule: Never let the fire smoulder.As long as there is solid wood in the firebox, there should beactive flames. Without flames,smoke will escape unburned,reducing efficiency and increas-ing pollution. With advancedsystems, you can achieve a reliable overnight burn whilemaintaining flaming combustionand still have enough charcoal in the morning to kindle a new fire.

Other Useful TipsArranging the Firewood – Smallpieces of firewood arrangedloosely in a crisscross patternburn quickly because the com-bustion air can reach all of thepieces at once. Larger pieces in acompact pile burn more slowlybecause there are fewer spaces forthe air to penetrate the load. Tryto add more than one piece ofwood to a fire – you need threeor more pieces to form a shel-tered pocket of glowing coalsthat reflect heat toward eachother and sustain the fire.

Firing in Cycles – Don’t expectthe fire to provide perfectlysteady heat output. A wood fireburns best in cycles. A cyclestarts when a new load of woodignites from a charcoal bed andends when that load is consumedand becomes another bed. Eachcycle provides three to eighthours of heating, depending onhow much wood you use, howmuch heat you need and howlarge your firebox is. Plan the firing cycles around your house-

hold routine. Be cautious aboutleaving the stove unattendedwhen you are away.

Using a Flash Fire – A flash fireis a small amount of woodburned quickly. Use it in springand fall when you just want totake the chill off the house. Theflash fire technique eliminatesthe smouldering fires that arecommon in the spring and fall.To build a flash fire, rake thecharcoal toward the air inletsand place several small pieces of


▲A small, loosely stacked fuel load isgood for short-duration flash fires.

▲A compact fuel load is good forextended firing cycles.

LOADING FOR A FLASH FIRE – Use afew small pieces of wood for shortfires to “take the chill off.” Loadthe wood loosely in a crisscrossarrangement. Let the fire burnbrightly until most of the solidwood is burned, then reduce theair setting. Flash fires are effectivein spring and fall when the heat-ing load is modest. By using theflash fire technique, you avoidsmouldering fires.

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wood on and behind it. Stack the pieces loosely in a crisscrossarrangement. Open the air inletto produce a hot, bright fire. You may reduce the air supplyslightly as the fire progresses, but never enough to extinguishthe flames.

Extending a Fire – To achieve alonger-lasting fire – to heat thehouse overnight or while you areaway – rake the coals toward theair inlet and use larger pieces ofwood placed compactly in thefirebox. Placing the pieces closetogether prevents the heat andflame from penetrating the loadand saves the buried pieces forlater in the burn cycle. Open theair inlets fully for five to 20 min-utes, depending on load size andfuel moisture content. When theouter pieces have a thick layer ofcharcoal, reduce the air controlin stages to the desired level.

Removing Ashes – Someadvanced combustion stoveshave ash pans as standard equip-ment or as an option. Some use a simple grate through whichashes drop into the pan. Othershave a plug in the stove floorthat, when lifted, allows ashes tofall into the pan. Make sure thatthe ash door is well closed andsealed. If your stove doesn’t have an ash pan, ask your localretailer for an ash handler intowhich you can scoop ashesthrough the loading door.

The ashes may contain live coalsthat can stay hot for days. If youdon’t dispose of them carefully,they can pose a fire hazard. Placeashes in their own metal con-tainer and keep that containeron a non-combustible floor,preferably outside the house.Special double-bottom ash con-tainers – with tight-fitting lidsdesigned to hold ashes until theyare cool – are available in stoveand fireplace stores.

Using a Thermometer – A ther-mometer helps you use yourwood burner more effectively,particularly if you can’t view thefire through glass doors. There aretwo types of thermometers. Onehas a probe that you put into theflue gas stream through a smallhole in the flue pipe. The secondis a magnetic thermometer thatsticks to the outside of the fluepipe or stove top.

Install the probe-type thermome-ter in the flue pipe about 50 cm(20 in.) downstream from theexit of the appliance – but neveron the appliance. The stack thermometer tells you how hot the flue gases are.

The magnetic thermometer, onthe other hand, measures thetemperature of the flue pipe, soits temperature will be lower thanthe probe thermometer’s.

Some manufacturers recommendthe use of a stove-top ther-mometer, rather than a stackthermometer. It works the sameway, but the temperature rangewill be different since it measuresthe surface temperature of the stove.

There are many ways to use ordispose of wood ashes. Some people use ashes for traction ondriveway ice, to control gardenpests or to reduce soil acidity.Other people simply bury them.Rural municipal waste disposalsites usually have special areas forashes. Consider disposing of yourwood ashes in a safe, clean andenvironmentally friendly way.


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When you fire the stove at a hightemperature to drive moisture outof the fuel, use a thermometer totell you when you can reduce theair supply. Every wood-heatingsystem behaves differently andthermometers vary, so there areno exact temperatures that youcan follow. However, to avoiddamaging the stove’s internalparts, don’t let the flue gas tem-perature rise above 460°C (860°F)on a stack temperature probe formore than a few minutes. Learnwhich burning connections resultin the stack temperature youmeasure. With experience, youwill be able to tell by the ther-mometer if you have set the aircontrol too low and when youshould reload.

Advanced combustion woodstoves do not need thermometersas much as older equipmentdoes. You can check the condi-tion of the fire visually. If the fire is burning properly, the glassdoor stays clear. If the glassbecomes hazy or develops darkstains quickly, the fire has beenturned down too low or the firewood is too wet. The glassshould stay clear when the firehas a higher heat output and the firewood is of good quality.Another indicator is the flameitself. The more complex theflame, the better the combustionin the stove.

The EfficientWood Fire in anAdvanced StoveWhen you master the techniquesfor efficient wood burning, hereis what you should see.

• When wood burns, it flamesuntil only charcoal remains.(If there are no flames, some-thing is wrong.)

• If there are firebricks in thefirebox, they will be tan,never black.

• Steel or cast-iron parts in thefirebox will be light to darkbrown, never black or shiny.

• If the wood is seasoned andwell split, the air settings are correct and the load isarranged properly, a new loadof wood will ignite rapidlyfrom the charcoal – somepieces will be flaming beforethe door is closed. If theappliance has a glass doorwith an air wash, it will beclear. If the appliance has aglass door without an airwash, it will be hazy, but itshould never be black.

• The exhaust from the top ofthe chimney will be clear or,in winter, white with steam.A plume of blue or greysmoke indicates smoulderingand poor combustion.


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The efficiency and convenienceof your wood-heating systemdepend significantly on the qual-ity of the fuel wood you burn.The four main factors that influ-ence how firewood burns aremoisture content, piece size,wood condition and tree species.

The moisture content of thewood affects the rate at which itburns and the efficiency of com-bustion. When trees are cut, thewood moisture content canrange between 35 and 60 percentby weight. Wood that is this wet is hard to ignite and slow toburn. It also hisses and sizzles inthe firebox. It combusts poorlyand produces large amounts ofair pollutants. Energy from theburning fire is used to boil offthe moisture, which reduces efficiency. Wet wood is the mostcommon problem with woodheating. If you think you have a problem with your stove’s per-formance, check the dryness of your fuel first. Properly seasonedwood ignites readily, flames easily and burns efficiently.

Cut and split firewood in theearly spring. Stack your woodoutside. It dries best if you keepit off the ground and covered.Allow room for the air to flowunder the stack and to circulatebetween the pieces. During thesummer, as warm breezes flowthrough the stacks and carryaway the water, the moisturecontent of the wood falls toabout 20 percent. One sign of

dry wood is checks or cracks inthe ends of the pieces. Properlydried firewood is darker on theends than freshly cut wood andweighs much less.

The size of the firewood piecesaffects the rate of combustion.Large pieces ignite and releasetheir energy more slowly thansmall pieces. Smaller, more finelysplit pieces are better for short,

hot fires, while larger pieces suitextended firing cycles. In gen-eral, the firewood produced bycommercial dealers comes inpieces that are larger across thanmodern wood-burners need. Youmay need to split some of thewood again before using it. Thelargest piece of wood for thenew, advanced stoves should be no more than about 15 cm(6 in.) across. You also need arange of smaller pieces for effective stoking.

Another factor that affects howfirewood burns is the wood’scondition. Wood that has beenlying in a swampy area or hasbeen cut too long ago (morethan three years) will be difficultto burn. It tends to look or feel rotten.

Store two or three days’ supplyof wood indoors, making surethat it is clean and dry. In winter, when you bring wooddirectly in from the cold outdoors and immediately load it into the appliance, it may initially cool the fire and preventproper combustion.

Remember, storing wet woodindoors could create mouldinside the house, so you shouldlimit the amount of wood thatyou store inside.


13 Purchasing and Preparing Your Fuel Supply

Burning wet wood producesmore smoke than heat. Dried,well-seasoned wood will smokeless and give you more heat.One way to verify if a chunk ofwood is dry is to look for checksand cracks at the ends. A cordthat has been stacked to dryover one heating season shouldalso be dry enough to burn.However, if you aren’t sure, youcan test the wood with a mois-ture meter. To use it, merely jabthe prongs into a chunk of woodto get a reading. Ideally, thereading will be between 18 and 22. You can get a moisturemeter at some hardware storesfor between $35 and $60. Youwill also find them at yourhearth products retailer. High-end models, such as those usedin laboratories, are available foraround $240.

▲Look for checks and cracks at the ends.

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Several tree species are used forfirewood, and those you choosewill affect your wood-burningsystem. Below is a list of the treespecies commonly used for fire-wood, according to their relativedensities. Trees at the top of thelist have the hardest wood andthe most energy per cord, whilethose toward the bottom of thelist are the softest and have theleast energy per cord. Regardlessof where you live and whatspecies are available, try to mixthe load as much as possible.This will ensure that you

do not use too much wood ofone species as your primary fuel source.

The energy content of wood perdry kilogram (i.e., per unit ofweight) is similar regardless ofspecies. However, the energy output from each piece of wood(weight per unit volume) of various species differs widely.Wood is generally sold by volume(cords), which means the energyper cord can differ widely amongdifferent species of wood. In gen-eral, hardwoods like maple, oakand beech are denser and havemore energy per piece than soft-woods such as pine, spruce andcedar. Softwoods and hardwoodstend to burn differently due to differences in density andresin content.

In most cases, when and where it is available, hardwood is the preferred firewood because ittends to produce a longer-lastingburn. Softwood can also be usedsuccessfully for fires, even insome of the coldest areas of thecountry. Softwoods are also byfar the most common trees onCanada’s coasts and northernareas. If you use softwood, youmay need a wood stove with alarger firebox to handle thelarger volume needed for thesame amount of heating power.Even in areas where hardwoodsare plentiful, softwood is a goodfuel in the spring and fall whenthe heat demand is lower. Thenew high-efficiency stoves andfireplace designs burn both hard-wood and softwood equally well.

Buying Firewood

Try to buy your wood fromsomeone who uses good forest management practices.Environmentally sound woodlotmanagement involves thinningout dying and damaged trees andless desirable species. To supportsustainable forestry practices, usewood from a blend of species;burn the softer woods – such aspine, poplar and aspen – in thespring and fall. This way, youhelp ensure that wood remains a renewable energy source forhome heating.

When you support woodlot own-ers who manage their lotsresponsibly, thereby providing asustainable mix of trees, you helpensure that wood remains arenewable energy source forhome heating.


Density of CommonFirewoodsHere is a list of the tree speciescommonly used for firewood.Those at the top of the list arehardest and those toward the bot-tom of the list are the softest.

IronwoodRock elmHickory

OakSugar maple

BeechYellow birch

Ash Red elm

Red maple TamarackDouglas firWhite birch

Manitoba mapleRed alderHemlockPoplarPine




Try to mix your wood species asmuch as possible so that you usehardwoods and softwoods whenthey are available. Using a mix ofspecies helps maintain the forest’snatural diversity.

How is firewood measured forsale? As stated in MeasurementCanada’s official brochure BuyingFirewood? Don’t Get Burned!,most firewood in Canada is soldby the cord.

How do you know when a cord isa cord? A cord is a legal unit of measurement defined bythe Weights and MeasuresRegulations as 3.62 m3 (128 cubicfeet) of stacked roundwood(whole or split, with or withoutbark) containing wood and air-space with all bolts of similarlength piled in a regular mannerwith their longitudinal axesapproximately parallel.

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Firewood CordsFirewood is measured and sold inunits called cords. A full cordmeasures 1.2 ✕ 2.4 ✕ 1.2 m(4 ✕ 8 ✕ 4 ft.) and is the officialfirewood measure. However, longlengths, such as 1.2 m (4 ft.), areusually cut into smaller piecesfor home heating. Other terms –such as face cord, stove cord orfurnace cord – are used todescribe a stack of wood measur-ing 1.2 ✕ 2.4 m (4 ✕ 8 ft.), withthe length of the pieces shorterthan 1.2 m (4 ft.). Firewood ismost often sold in face or stovecords made up of pieces 30 or 40 cm (12 or 16 in.) long.

These various cord measures can be confusing. If you want to compare prices from severalsuppliers, take a tape measure to each dealer’s yard and

measure a few pieces to deter-mine an average length. If thedealer doesn’t price the wood inthe standard full-cord measure,convert the price to this basic unit.

Three examples are provided on page 52 to illustrate the conversion.

If possible, avoid buying fire-wood in units that can’t beconverted to the standard fullcord. For example, truckloads ofwood are difficult to measure soyou could be overcharged with-out knowing it. MeasurementCanada’s brochure BuyingFirewood? Don’t Get Burned! highlights some precautions youcan take when you receive yourwood, to ensure that you are get-ting the amount you paid for.

Tips for Buying WoodWhen ordering firewoodWhen ordering your wood, askthe dealer what kind of wood itis and how the cords are mea-sured so that you aren’t surprisedwhen the truck arrives. Also, askfor the wood to be deliveredstacked in the truck, so you canmeasure it before it is unloaded.If this isn’t possible, stack thefirewood immediately followingdelivery. Measure the length,width and height of the stack,and calculate the quantity thatyou received.

When receiving the firewoodBe present when the wood isdelivered. Don’t rely on a neigh-bour to accept delivery on yourbehalf. When the wood arrives,take the time to randomly examine some pieces in front of


▲THE FIREWOOD CORD – Firewood is measured in cords. A full cord measures 1.2 m✕ 2.4 m ✕ 1.2 m (4 ft. ✕ 8 ft. ✕ 4 ft.). Many firewood dealers sell partial cordscalled face or stove cords. Pictured are three face cords with pieces measuring anaverage of 40 cm (16 in.). Together, these three face cords make up one full cordand should equal 3.6 m3 (128 cubic feet).

What to burn?ALWAYS BURN

• Clean, dry wood• Properly seasoned,

split wood • A mix of hard and soft

wood, where possible,depending on what is available in your region


• Wet or green wood • Household garbage

such as plastic orcardboard

• Painted or stained wood• Pressure-treated wood• Particleboard or plywood• Ocean driftwood• Glossy magazines• Any materials prohibited

by local by-laws

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the delivery person to make surethe load isn’t rotten. Then makesure that you get a receipt whichshows the quantity and type offirewood purchased; the seller’sname, address and telephonenumber; and the price paid.

Know your wood, and makesure it is dry if you’ve paid for seasoned woodAlthough you may not be anexpert on various tree species,make an effort to learn about thespecies in your area. Therefore, ifyou are expecting to receive acertain species, you can identifyit. Moreover, if you are paying apremium to make sure the woodhas already been seasoned, lookfor checks and cracks at the endof pieces or jab a few pieces withyour moisture meter.

Before using any firewoodVerify that the quantity receivedis the same as the quantity thatyou paid for. If there is a differ-ence, contact the seller beforeyou use any of the firewood. Ifthe quality of the wood is ques-tionable – if it is rotten, mouldyor soaking wet – you aren’t getting your money’s worth.

Buying Firewood? Don’t GetBurned! is available on-line athttp://www.nrcan.gc.ca/es/erb/reed/public_e.htm.

Where to Get FirewoodYou can usually find firewooddealers listed in the Yellow Pagesof the telephone directory or inthe classified ads of your localnewspaper. Better yet, get a referral from neighbours whopurchase firewood.

You may be able to get a fuelwood permit to cut the treesyourself from the local office ofyour provincial or territorial nat-ural resources ministry. Sawmillsmay also have cut-offs, slabs andcull logs that they sell as fire-wood. You will still have to cutthe wood into pieces, so thatthey fit into your stove properly.If you fill the stove with toomuch wood without leavingenough space around the piecesfor good air and fire circulation,you won’t get an efficient fire.

One way to save money is to buylogs from a local woodlot. Seekout one that is known to practisesustainable forest management.Unprocessed logs usually mea-sure 1.2 to 2.4 metres (four toeight feet) in length. You willneed a chainsaw to cut the logsto length and a splitting ax ormaul to split the wood into theright size of pieces.


Example 1Woody Cutters sells a face cordfor $55. You find that the pile is1.2 m (4 ft.) high and 2.4 m(8 ft.) long, with an averagelength of 40 cm (16 in.). To findthe price for a full cord, divide theimperial length of the logs(16 in.) into the full cord length(48 in.), then multiply it by theprice, as follows:

(48 [full cord length] ÷ 16 [average chunk length]) ✕ $55 (price of face cord)

= $165 (price of full cord).

Therefore, Woody Cutters sellsfirewood for $165 per full cord.

Example 2The Charlebois Sugar Bush sells a stove cord for $45. The pile measures 1.2 m (4 ft.) by 2.4 m(8 ft.), with an average length of30 cm (12 in.). To determine theprice for a full cord, the followingcalculation is used:

(48 [full cord length] ÷ 12 [average chunk length])✕ $45 (price of stove cord)

= $180 (price of full cord).

Therefore, the Charlebois SugarBush sells firewood for $180 perfull cord.

Example 3The Cut Above Woodlot sells a 1.2 m ✕ 2.4 m ✕ 45 cm (4 ft. ✕ 8 ft. ✕ 18 in.) furnacecord for $75. To determine theprice for a full cord, the calcula-tion is as follows:

(48 [full cord length] ÷ 18 [chunk length]) ✕ $75 (price of furnace cord)

= $200 (price of full cord).

Therefore, the Cut Above Woodlotsells firewood for $200 per fullcord.

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How Much is Enough? Only experience can tell you howmuch wood you will need for aheating season. A medium-sizedmodern home, if heated exclu-sively with wood, requiresbetween three and five full cordsper winter – or more if the houseisn’t energy efficient. On the otherhand, the same house with ahigh-efficiency combustion woodstove that is properly located inthe main living area might useonly one or two full cords. Youneed more wood if your area isvery cold; if your house is large,leaky or poorly insulated; or if youonly use softwoods.

Properly stored firewood will lastfor more than one year, so buy alittle extra if you can find goodquality wood at a reasonableprice and if you have a place tostore it outdoors.

Are wood pelletsyour fuel source?Buying wood pelletsYou can purchase bags of woodpellets in the seasonal section oflarge home improvement storesor at local hardware stores. Youcan often buy wood pelletsthrough agricultural co-ops. The bags come in several sizes; the most common is 18.1 kilo-grams (40 pounds), which maycost between $4 and $6. You canhave bulk orders delivered on a wooden pallet for a deliverycharge. Ask your dealer wherethe pellets were stored over thewinter. If they were stored out-doors, make sure that the pelletsthat you purchase are dry, or elseyou will be paying for mushysawdust which you can’t use in your stove.

If your pellet stove is yourhome’s primary or secondaryheating source, make sure thatyou have enough bags on handbefore the heating season begins.

Storing wood pelletsWood pellets are simply com-pressed pellets of sawdust, so you must store them in a dryarea, where they will not take onmoisture or bugs. You can storebags of wood pellets in the base-ment or an attached garage, but they should be kept off theground, preferably on the palleton which they are delivered.Stack them so that the pile won’ttopple over when you reach for abag. Pick a spot to pile your bagsand leave them there. Excessivehandling of the bags could cause

the pellet coating to crack, leav-ing you with miniature handfulsof sawdust.

Buying and storing pellets made of corn and corn kernelsSome stoves are fuelled by cornpellets or corn kernels, whichmay be more difficult to find.Corn-burning stoves have notbeen rated for energy efficiencyor smoke emissions, and someinsurance companies will notinsure them. If you use a cornstove, you still must keep thefuel dry. Corn pellets and kernelsmay be available through an agricultural co-op.

Reuse and recycle your pellet bagsThe pellets come in poly bagsthat can be easily reused and, in some cases, recycled. Yourmunicipality can confirm whichdisposal method is the mostenvironmentally friendly foryour area.

Remember, storing wet woodindoors could create mouldinside the house, so you shouldlimit the amount of wood thatyou store inside.


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You may want to calculate thecost of using wood fuel com-pared with conventional fuelssuch as oil, natural gas, propaneor electricity. The procedure outlined here can provide rea-sonably accurate comparativecosts. You will first need to findout the cost of the fuels in yourarea that you want to compare.

Step 1.Determine thePrice of EnergySources in Your AreaCall your local suppliers to findout the average cost of theenergy sources you are compar-ing. The cost should be the totalcost as delivered to your home.Be sure to get the prices in thesame units for the energysources, as shown in Table 1.

Note that the figures for firewoodare for full cords (1.2 ✕ 2.4 ✕ 1.2 m,or 4 ✕ 8 ✕ 4 ft.). Often, you willbe quoted the price for a face orstove cord, or one third of a fullcord. If so, multiply by three toget the price for a full cord. Theenergy content figures are in met-ric units called megajoules (MJ).

Step 2. Select theType of HeatingSystems You Wishto CompareChoose the types of equipmentyou want to compare from the list of systems in Table 2.Seasonal efficiency figures for theequipment are in the right-handcolumn. Using these efficiency

figures, you can calculate thesavings you can achieve byupgrading an older system to a new, more efficient applianceand/or by changing to a differentenergy source.


14 Comparing Annual Heating Costs

Table 1: Energy Content and Local Price of Various Fuels

Fuel Energy Content Your Local Price

Oil . . . . . . . . . . . . . . . . . . . 38.2 MJ/litre ______/litre

Electricity . . . . . . . . . . . . . . 3.6 MJ/kWh ______/kWh

Natural Gas . . . . . . . . . . . . 37.5 MJ/m3 ______/m3

Propane . . . . . . . . . . . . . . . 25.3 MJ/litre ______/litre

Hardwood (air dried) . . . . . 30 600 MJ/cord ______/cord

Softwood (air dried) . . . . . . 18 700 MJ/cord ______/cord

Mixed Hardwood (air dried) . 25 000 MJ/cord ______/cord

Wood Pellets . . . . . . . . . . . 19 800 MJ/tonne ______/tonne

Table 2: Typical Seasonal Heating System Efficiencies

Fuel Type of System % Efficiency

Oil Conventional Burner 60Retention Head Burner 70–78Advanced Mid-Efficiency Furnace 83–89

Electricity Central Furnace or Baseboard 95–100

Natural Gas Central Furnace – conventional 55–65– powered exhaust 75–82– condensing 88–96

Propane Central Furnace – conventional 55–65– powered exhaust 76–83– condensing 85–93

Wood Central Furnace 45–55Conventional Stove (properly located) 55–70“High Tech” Stove (properly located) 70–80

Wood Pellets Pellet Stove 55–80

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Step 3. Choose Housing Type andAnnual HeatingLoads

From the list in Table 3, selectthe city and housing type thatare closest to yours. The heatingloads are in metric units calledgigajoules (GJ).


Table 3: Typical Annual Heating Loads in Gigajoules (GJ)for Various Housing Types in Canadian Cities

Old New New Semi- New City Detached Detached Detached Townhouse

Victoria/Vancouver 85 60 45 30

Prince George 150 110 80 60

Calgary 120 90 65 50

Edmonton 130 95 70 55

Fort McMurray/Prince Albert 140 105 80 60

Regina/Saskatoon/Winnipeg 130 90 70 50

Whitehorse 155 115 85 60

Yellowknife 195 145 110 80

Thunder Bay 130 95 70 55

Sudbury 120 90 65 50

Ottawa 110 75 55 40

Toronto 95 65 45 35

Windsor 80 55 40 30

Montréal 110 80 60 45

Québec 115 85 65 50

Chicoutimi 125 90 70 55

Saint John 105 75 60 45

Edmundston 120 90 65 50

Charlottetown 110 80 60 45

Halifax 100 75 55 40

St. John’s 120 85 60 45

Note: “New” means houses built after 1990, and “old” means houses built before1990. Due to construction practices, weatherizing and re-insulating (which can bedifferent from house to house), these figures are meant to be used only as generalguidelines; they should not substitute for an accurate heating requirement deter-mination, as discussed in Chapter 6.

Assumptions:New townhouse – inside unit, approximately 93 m2 (1000 sq. ft.)New semi-detached – approximately 139 m2 (1500 sq. ft.)New detached – approximately 186 m2 (2000 sq. ft.)Old detached – approximately 186 m2 (2000 sq. ft.)

Page 58: A Guide to Residential Wood Heating

Step 4. Using the FormulaCalculate the annual heatingcost as follows:

Enter the cost per unit of energyand divide it by the energy con-tent of the fuel (both figures comefrom Table 1). Select the annualheating load for your location andhousing type from Table 3, anddivide it by the efficiency of theproposed heating system fromTable 2. Multiply the results ofthese two calculations, then multiply that result by 100 000.

When doing this calculation,verify the fuel costs in your area, as prices may vary. Also, the energy consumption of your particular house may be significantly different from the nominal houses in Table 3.

SampleCalculationsExample 1The Burnett family has just built an open, detached home in Charlottetown, Prince EdwardIsland. They are thinking about buying a new, 83-percent efficient oil furnace. They wantto determine whether it will beless expensive to heat the housewith a high-efficiency advancedcombustion wood stove at 70-percent efficiency than withtheir good oil furnace. Oil costs45 cents a litre and mixed hard-wood costs $160 per cord.

• from Table 3, for a newdetached house inCharlottetown, annual heating load = 80 GJ

• from Table 1, energy contentof oil = 38.2 MJ/L and energy content of wood =25 000 MJ/cord

The annual cost of oil heatingwith a seasonal efficiency of 83 percent would be

(0.45 ÷ 38.2) ✕ (80 ÷ 83) ✕ 100 000 = $1,135.

The annual cost of wood heatingwith a seasonal efficiency of 70 percent would be

(160 ÷ 25 000) ✕ (80 ÷ 70) ✕ 100 000 = $731.

In this example, if wood dis-placed all of the oil previouslyused for heating, the Burnettswould save $404 per year ($1,135 – $731).


Energy cost/unit ✕

Heat load ✕ 100 000 =

Approximate annualEnergy content System efficiency heating cost

Page 59: A Guide to Residential Wood Heating

Example 2The Laurin family lives in an old,detached, relatively open-planhouse in Sudbury, Ontario. Theypresently heat their house withelectric baseboards at a cost ofeight cents per kilowatt hour(kWh). What would it cost themto heat with a high-efficiencyadvanced combustion woodstove with an efficiency of 70 percent? The cost of a fullcord of hardwood is $150.

• from Table 3, annual heatingload = 120 GJ

• from Table 1, energy contentof electricity = 3.6 MJ/kWhand energy content of wood = 30 600 MJ/cord

• seasonal efficiency of electricity = 100 percent andseasonal efficiency of wood = 70 percent

The annual cost of electric heating would be

(0.08 ÷ 3.6) ✕ (120 ÷ 100) ✕ 100 000 = $2,667.

The annual cost of wood heatingwould be

(150 ÷ 30 600) ✕ (120 ÷ 70) ✕ 100 000 = $840.

In this example, if the high-efficiency wood stove displacedall of the electricity previouslyused for heating, the Laurinswould save $1,827 per year($2,667 – $840).

Example 3The Tran family lives in an oldhouse in Prince George, BritishColumbia. They have an annualheating load of 150 GJ. They aretrying to decide whether to heatthe house with an efficient,direct-vent, freestanding propanefireplace at 72-percent efficiencyor an advanced combustionwood fireplace at 70-percent efficiency. Propane costs 59 centsper litre and a full cord costs $110.

• from Table 1, the energy con-tent of propane is 25.3 MJ/L

• the energy content of soft-wood is 18 700 MJ/cord

The annual cost of heating with propane would be

(0.59 ÷ 25.3) ✕ (150 ÷ 72) ✕ 100 000 = $4,858

The annual cost of heating withwood would be

(110 ÷ 18 700) ✕ (150 ÷ 70) ✕ 100 000 = $1,260

Therefore, it would cost theTrans $3,598 ($4,858 – $1,260)less per year to heat their house with wood instead of propane,given the fuel prices chosen.


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The demand for environmentallyacceptable energy alternativesshould ensure that wood heatingwill play an integral part of ourenergy mix for the foreseeablefuture. Many Canadians like you who use renewable energysources to heat their homes wantto make sure that these sourceswill remain sustainable. As well,they usually support model forest management practices.Moreover, with more highly efficient combustion technolo-gies in homes – technologies thatproduce more heat with fewerpollutants – residential woodheating is expected to remain asafe, clean and efficient home-heating option in the future.

Wood stoves have evolved signif-icantly since the late 1980s, andthey are now cleaner-burning,easier to use and provide betterenvironmental performance. Aswe understand more about effi-cient wood-burning techniquesand the need to reduce smokeemissions, wood heating will beamong the methods for improv-ing Canada’s energy security.More Canadian families willenjoy the benefits of advanced,certified clean-burning woodheaters.

Conventional fireplaces, oncecommon in Canadian homes, are declining in popularity. Theirlow efficiency, high levels of pollution, limited use and oftensevere functional problems out-weigh any claims to aestheticappeal. In their place, energy-efficient and low-emissionwood-burning fireplaces andinserts with their beautiful fire-viewing capabilities willbecome the accepted standard.These new fireplaces are as practical as they are attractive –something that can’t be said of older, conventional fireplaces.

As the cost of heating homeswith fossil fuels and electricitycontinues to rise, advanced wood burning offers an effectivealternative. In the future, moreCanadians – especially those living at the urban fringe andbeyond – will return to Canada’soriginal source of fuel. Installingan advanced technology woodstove, fireplace or insert in theprimary living area may reducethe need to directly heat unoccu-pied parts of our homes. As webetter understand the environ-mental and social costs ofenergy, the move to renewable,efficient and self-reliant woodwill make more sense for manyCanadians.


15 The Future of Residential Wood Heating

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Heating your home with woodrequires a serious investment. For more information or tips onhome heating with wood, con-sult the following wood-heatingspecialists:

Fuel Wood• Provincial and territorial

ministries of naturalresources, energy or environment.

• Your local telephone directory, under “Firewood.”

• Classified ads in your localnewspaper.

• Word-of-mouth recommen-dations of owners whomanage environmentallysound woodlots.

Products andServices • Your local telephone

directory, under “Chimneys,” “Chimney Cleaning,”“Heating Contractors,”“Fireplaces and Wood Stoves – Retail.”

• Visit your local hearth products store.

• Hearth Patio and BarbecueAssociation of Canada orAssociation des profession-nels du chauffage.

Hearth Patio andBarbecue Association ofCanada (HPBAC)To find out more about hearthproducts or to locate qualifiedindustry professionals, look forthis logo in telephone directories.

Tel.: (705) 788-2221E-mail: [email protected]

Association desprofessionnels du chauffage(APC)

C.P.170, succursale BeaubienMontréal QC H2G 3C9Tel.: (514) 270-4944Fax: (514) 270-5488E-mail: [email protected]

Contact the APC for fact sheetsand other information on woodheating in Quebec.

CSA International178 Rexdale BoulevardToronto, ON M9W 1R3

Contact CSA International forcopies of standards mentioned in this guide.

SafetyInformation• Your municipal office for

building inspection and fireinspection

• Your provincial or territorialfire marshal’s office

• Fire Prevention Canada (1 800 668-2955 or


Wood Energy TechnologyTransfer Inc.365 Bloor Street EastSuite 1807Toronto ON M4W 3L4Tel.: 1 888 358-9388

Web site: http://www.wettinc.ca

Consumer TipsThe Wood Heat Organization Inc.410 Bank Street, Suite 117 Ottawa ON K2P 1Y8Tel.: (613) 757-2290Fax: (613) 757-0277Web site:http://www.woodheat.org

A comprehensive database onfrequently asked questions isavailable on the Wood HeatOrganization’s Web site.

Hearth, Patio & Barbecue Association of Canada

a n I n t e r n a t i o n a l A f f i l i a t e o f H P B A


For More Information

Page 62: A Guide to Residential Wood Heating

Publications on ResidentialWood-Heating A Guide to Residential WoodHeating is part of a series ofbuyer’s guides for renewableenergy systems for residentialuse. Other documents on resi-dential wood heating include the following:

• All About Wood Fireplaces

• An Introduction to HomeHeating With Wood

• Buying a High-Efficiency Wood-Burning Appliance

• Getting the Most Out of Your Wood Stove

Visit the Renewable andElectrical Energy Division (REED) Web site for these on-line publications or others at http://www.nrcan.gc.ca/redi.

Call 1 800 387-2000 toll-free to get your copies of these free guides.

For additional copies of A Guideto Residential Wood Heating orother publications on energy efficiency, write to

Energy PublicationsDLSOttawa ON K1A 0S9Tel.: 1 800 387-2000

In the National Capital Region,call 995-2943Fax: (819) 994-1498

Canada Mortgage and Housing CorporationCanadian Housing

Information Centre700 Montreal RoadOttawa ON K1A 0P7Tel.: (613) 748-2367Fax: (613) 748-4069

For a copy of Buying Firewood?Don’t Get Burned!, contactMeasurement Canada, anIndustry Canada agency, athttp://strategis.ic.gc.ca/sc_mrksv/meascan/engdoc/homepage.html.

Call the ministry of energy or natural resources in yourprovince or territory.


Page 63: A Guide to Residential Wood Heating

www.burnitsmart.org www.chauffageaubois.org

Burn it Smart!Enjoy the fire, not the smoke.