Heating SystemsHeating Systems

Thermal Energy on the Move:Thermal Energy on the Move: Conduction:Conduction: the transfer of energy through matter the transfer of energy through matter

by direct contact of particlesby direct contact of particles Pans on a stove transfer the heat by conduction to the food.Pans on a stove transfer the heat by conduction to the food.

Convection:Convection: the transfer of energy by the bulk the transfer of energy by the bulk movement of matter.movement of matter. used withused with fluids:fluids: any material that flows (liquids & any material that flows (liquids &

gases)gases) Ocean and wind currents are a global form of convection Ocean and wind currents are a global form of convection

Radiation:Radiation: the transfer of energy in the form of the transfer of energy in the form of waves.waves. The sun and a camp fire the side of you that faces the heat The sun and a camp fire the side of you that faces the heat

source is warmed but the other side can be cold.source is warmed but the other side can be cold.

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Conventional Heating Conventional Heating Systems:Systems:

All heating systems must have a source All heating systems must have a source of energy.of energy.

- Electricity - Electricity

-Fuels Fuels -Fossil FuelsFossil Fuels: Oil, Natural Gas, LP: Oil, Natural Gas, LP-Biomass:Biomass: Wood, Sawdust, Vegetable oil, etc Wood, Sawdust, Vegetable oil, etc

- Solar (Active & Passive Systems)- Solar (Active & Passive Systems)

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Electric Heating SystemsElectric Heating Systems

Radiant Electric HeatRadiant Electric Heat electricity passes through a electricity passes through a wire called a heating wire called a heating element. The wire has a lot element. The wire has a lot of resistance to electron of resistance to electron flow so it gets extremely flow so it gets extremely warm.warm.

Radiant Electric can beRadiant Electric can be baseboard units or in the baseboard units or in the floor, walls or ceiling.floor, walls or ceiling.

Advantage: Low cost to install, individual control toAdvantage: Low cost to install, individual control to each room.each room.Disadvantage: Higher cost to operate.Disadvantage: Higher cost to operate. 5 - 6

Central Heating Systems:Central Heating Systems: A A central heatingcentral heating system generates heat for system generates heat for

an entire building or group of buildings an entire building or group of buildings from one location: from one location:

A furnace or boiler is used to convert fuel into heat.A furnace or boiler is used to convert fuel into heat.

Most common heat Most common heat

distribution systems.distribution systems. Forced hot water Forced hot water Forced hot airForced hot airSteam heatSteam heat

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Hot Water Heating System:Hot Water Heating System:Forced-Water Systems:Forced-Water Systems: Common fuel sources – Common fuel sources –

Natural Gas and OilNatural Gas and Oil

Water is heated in the furnace an a Water is heated in the furnace an a pump is used to move hot water pump is used to move hot water through a series of pipes from the through a series of pipes from the furnace to the areas to be heated.furnace to the areas to be heated.

The heated water will go to baseboards The heated water will go to baseboards to obtain convection currents in the to obtain convection currents in the room or use radiant heating in a floor, room or use radiant heating in a floor, wall or ceiling.wall or ceiling.

Advantage: More even heat, Furnace can Advantage: More even heat, Furnace can supply domestic hot water, zone heating, often supply domestic hot water, zone heating, often easier to adapt to solar hot water.easier to adapt to solar hot water.

Disadvantage: Slower to warm a space.Disadvantage: Slower to warm a space.

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BaseboardsBaseboards Both Electrical and Both Electrical and

Hydronic baseboards have Hydronic baseboards have the heating element or the heating element or copper pipe in the center of copper pipe in the center of metal fins. metal fins.

What is the purpose of the What is the purpose of the fins?fins?

Answer: Allow for more surface area to dissipate the heat from the heating element or the copper pipe full of hot water.

Cool air near the floor gets warmed as it passes by the fins. As the air warms it will rise to the ceiling as part of convection currents that will circulate in the room.

Forced Air Heating Systems:Forced Air Heating Systems: Common fuel sources – Common fuel sources –

Natural Gas, Oil, LPNatural Gas, Oil, LP

A blower (fan) is used to move A blower (fan) is used to move warmed air through a series of warmed air through a series of large ducts to vents in each large ducts to vents in each roomroom

Warm air circulate by Warm air circulate by convection, cool air returns to convection, cool air returns to the furnace to be reheated.the furnace to be reheated.

Advantage: Fast acting heat, Air ducts Advantage: Fast acting heat, Air ducts make it easier to install A/C, easy to make it easier to install A/C, easy to add humidifiers and filters.add humidifiers and filters.

Disadvantage: Heat tends vary Disadvantage: Heat tends vary frequently, tends to be dustier if not frequently, tends to be dustier if not maintained.maintained.

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Steam Heating Systems:Steam Heating Systems: Common fuel sources – Common fuel sources –

Natural Gas and OilNatural Gas and Oil Water is heated to above 100 Water is heated to above 100 C at which C at which

it turns to steam in a boiler not a furnaceit turns to steam in a boiler not a furnace Steam, is under pressure, is forced to the Steam, is under pressure, is forced to the

convector in the rooms of the building. convector in the rooms of the building. This causes convection currents.This causes convection currents.

As the steam gives off its heat as it As the steam gives off its heat as it condenses and gravity returns water to the condenses and gravity returns water to the boiler.boiler.

Advantage: Used often in larger building or Advantage: Used often in larger building or campus. A large quantity of heat with little campus. A large quantity of heat with little water (steam)water (steam)

Disadvantage: Higher temperatures are Disadvantage: Higher temperatures are required this results in higher pressures in required this results in higher pressures in the pipes which can stress pipes and the pipes which can stress pipes and fittings.fittings.

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Types of Solar Heating:Types of Solar Heating:Passive Solar Heating:Passive Solar Heating: use no fans or use no fans or

mechanical devices to mechanical devices to transfer heat from one transfer heat from one area to another.area to another.

South facing wall is full South facing wall is full of windowsof windows other walls other walls are well insulated with are well insulated with few windowsfew windows

Trombe walls (floors too) Trombe walls (floors too) absorb the heat from the absorb the heat from the sun as the room cools, sun as the room cools, the heat that was the heat that was absorbed is released to absorbed is released to heat the roomheat the room

Advantage: Heat Advantage: Heat source is free, Few or source is free, Few or no mechanical parts.no mechanical parts.Disadvantage: Must Disadvantage: Must have a southern have a southern exposure. North side exposure. North side of the house is cooler, of the house is cooler, installation is costly. installation is costly. Hard to regulate heat Hard to regulate heat in summer.in summer.

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Types of Solar Heating:Types of Solar Heating:Active Solar Heating:Active Solar Heating:

The energy is absorbed from the The energy is absorbed from the sun by the solar collector, warmed sun by the solar collector, warmed liquid* is pumped to a heat liquid* is pumped to a heat exchanger to heat water that is exchanger to heat water that is forced through the house by forced through the house by mechanical devices (Pumps) (Fan)mechanical devices (Pumps) (Fan)◊◊..

solar collectors are usually black solar collectors are usually black help absorb the heathelp absorb the heat and covered and covered with glass to reduce energy loss.with glass to reduce energy loss.

Advantage: Heat source is free, House doesn’t have to have a Advantage: Heat source is free, House doesn’t have to have a

southern exposure. Can heat domestic water and heat building southern exposure. Can heat domestic water and heat building

space.space.

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Disadvantage: installation is $. More maintenance than Passive.Disadvantage: installation is $. More maintenance than Passive.

R-VALUER-VALUE The R-value is the measure of

resistance to heat loss through a material.

Greater the R-value, the more Greater the R-value, the more effective the insulation is. Preventing effective the insulation is. Preventing heat loss in winter and preventing heat loss in winter and preventing heat gain in summer.heat gain in summer.

Two materials that have the same Two materials that have the same

R-value indicates similar insulation R-value indicates similar insulation performance The amount of material performance The amount of material may vary.may vary.

TYPES OF INSULATIONTYPES OF INSULATION

BattsBatts Rolls Rolls Loose-fillLoose-fill Rigid foam boardsRigid foam boards BlanketBlanket ReflectiveReflective

www.kyanite.com/newimages/insulation.jpg

www.rsarecycle.com/images/insulation.jpg

www.hamiltonsupply.com/images/JM%20Roll%20Insulation.gif

starbulletin.com/2001/05/19/features/artc.jpg

Climate Map w/ Recommendations for R-Values URL

Vapor BarriersVapor Barriers A vapor barrier is a material A vapor barrier is a material

that reduces the rate at which that reduces the rate at which water vapor can move through water vapor can move through a material. a material.

Warm air tends to hold water Warm air tends to hold water vapor. vapor.

The moisture that is in the air The moisture that is in the air condenses on the first cold condenses on the first cold surface it encounters. If this surface it encounters. If this surface is within an exterior surface is within an exterior wall cavity, wet insulation and wall cavity, wet insulation and framing will be the result. framing will be the result.

Forced Air Heating Systems:Forced Air Heating Systems:

Hydronic Perimeter Heating Hydronic Perimeter Heating SystemSystem

oikos.com/esb/48/ radiantheat.html www.butlerrec.com/

Baseboard - ConvectionRadiant - Floor Installation

www.h2oplumbing.com/services/ services.htm

Recommended Recommended InsulationInsulation