Habitat Studio has built over 40 houses with Energuide Ratings of 86 or better
Our minimum energy specification results in a Energuide rating of 82
Net Zero Energy
• Produces all of its own energy for Heating, DHW, Lighting and Appliances on site over the course of a year.
• Next to impossible without aggressive conservation
!
• 54000 C Heating Degree Days
• -340 C Design Temp
Habitat Studio NetZero Energy Houses so far
Riverdale NetZero Mill Creek NetZero
Belgravia NetZero Parkland NetZero
South Windsor Park NetZero Holyrood Near
NetZero Retrofit
Edmonton
Winnipeg
• 59000 C Heating Degree Days
• -350 C Design Temp
Parkland NetZero• LEED Platinum 4000 sqft two story with
finished basement, complex shape. 6 occupants
• 16,800 watts of PV, ground mounted with 2 way tracking
• 55% passive solar heated, 12% south glazing with 2 1/2” concrete floor
• Electric boiler with in floor distribution.
• Good solar site for house and array
net-zero.ca/
Habitat Studio Net Zero houses this year
Allen Residence
Shute Salvalaggio Residence Kennepohl Franchuk Residence
Kosowan Ferrero Residence
• Panelized factory built 2x8 Filled with 5" 2lb Spray foam & 2.25" fibreglass
• East west facing site
• Air source heat pump heating
• Air source heat pump hot water
• 16.3 kW photovoltaic system
• Landmark builds over 1000 homes per year
Landmark Group of Builders Ltd.
Net Zero in 10 easy steps
• Model the energy performance of your preliminary design
• Use the modelling results to optimize the building envelope and passive solar gain
• Reduce base loads
• Domestic hot water
• Lighting and appliances
!
• Evaluate air source heat pumps or geothermal and other renewables
• Size PV to meet remaining total loadEnergy Reduction
Renewable Energy Collection• Site assessment
• Preliminary design
• Optimize passive solar if available
• Finish detailed architectural and system design
Using modelling to optimize the cost of conservation measures
For Net Zero Energy at the Lowest Cost
Cost per kWh/year of energy collection*=Cost per kWh/year of energy
conservation
Cost per kilowatt-hour/year (kWh/a) of any energy conservation measure
Cost of the measure divided by energy saving in kilowatt-hours per year(kWh/a)=
*Current cost of PV in Edmonton is $3.00 to $3.50 for the capacity to generate
1 kWh/year
N.B. This works until you run out of roof space and it ignores the fact that there are primary energy consequences to exporting large amounts of energy
to the grid in summer and drawing it back in winter
• Conservation is the simplest, most economical and most reliable route to energy and greenhouse gas reduction - better than solar PV, solar hot water, better than geothermal
• Without aggressive conservation there’s not much point in planning for renewable energy collection
• The most benign energy available is the energy you don’t ever need.
Building a Better Building Envelope
• Very hard to fix the building envelope later
Preliminary Design
• Usual home design considerations- Job #1 is to build a great place to live.
• Keep living spaces on the south side to make best use of passive solar potential
• Try to accommodate space for PV generation
• Keep the shape simple and compact
Site Assessment
• Evaluate the Solar Potential
• Consider potential shading from buildings, trees, etc.
• Potential for renewable energy collection
• Passive solar is not often available on urban lots, but when it is, it makes net zero a lot easier.
S
January 15
Belgravia NetZero• 1900 sq. ft. with basement suite (TFA 1981sqft /184 m2 ),
currently one occupant
• Excellent solar site
• 7740 watts of PV- 5160 watts moveable, 2580 watts fixed
• 12.6% south glazing area, 2 1/2” concrete on floors
• Dead simple, very low cost electric baseboard heaters and DHW
• Incremental investment in conservation was partially paid for by savings on the mechanical system
• Has used ~5600kWh/a for heating, lighting, appliances, and DHW and generated 9600 kWh- a 4000 kWh surplus for two years in a row. (30kWh/m2 all in).
19°
53°
885 square feet
375 square feet
Roof shape and orientation
• When PV costs were $6.00 to $7.00 per installed peak watt we angled the roof to get as much output as possible from each module.
• Now with PV costing $3 to $3.50 per installed peak watt it makes more sense to accommodate as many modules as possible and accept lower output per module.
Modelling
• Good modelling is everything. Designing for net zero at an optimum cost is almost impossible without it. You're shooting in the dark
• Model early in the design process while it is still easy to make changes and before people get attached to particular configurations
• Model in house if possible, but if you can’t you can still learn a lot by playing with the input values in a model set up an expert evaluator.
• It seems like a lot of work, but can be done in a couple of hours after you’ve done it a few times.
Modelling Tools
• HOT2000 is tested, tried, and true. It is the basis for most Canadian labelling and rebate programs
• Passive House Planning Package (PHPP) is excellent. It gives very detailed feedback and lets you dial in the important details
Envelope Modelling/Optimization
• Determine Current PV cost or other benchmark energy price.
• Evaluate envelope upgrades with respect to cost per kWh/year of energy saved.
• Optimize envelope specifications: foundation,walls, roof, windows, air tightness.
• Extra conservation cost can often be offset by simpler mechanical systems
Net Zero in 10 easy steps
• Model energy performance of preliminary design
• Use the modelling results to optimize the building envelope and passive solar gain
• Reduce base loads
• Domestic hot water
• Lighting and appliances
!
• Examine / Model solar domestic hot water and heating
• Consider Air Source Heat Pumps or Geothermal
• Size PV to meet remaining total load
Energy Reduction
Renewable Energy Collection• Site assessment
• Preliminary design
• Finish detailed architectural and system design
Options for walls with better performance than 2x6 16” O.C.• 2x6 @ 24” O.C. (R 17.9 vs R16.5)
• 2x6 or 2x8 with high density foam -
• ICFs (Insulated Concrete Forms)
• SIPs (Structurally Insulated Panels
• 2x6 with 2x3 Strapping
• 2x8 24” O.C. with OVE details
• Double 2x4 walls - 10” to 16” thick
• Saskatchewan Double 2x4 wall
• 2x4 with Larsen trusses
• 2x6 with exterior rigid insulation foam or rigid Roxul-
• REMOTE walls - see CCHRC site for some great pamphlets
Considerations in choosing a wall system
• Lowest cost per effective R value
• Ease of getting ultra air tightness.
• Continuous insulation layer- no thermal thermal bridges
• Durability- vapour openness.
• Ease of construction
• not too disruptive of normal construction sequence
• minimal work from scaffolding
• As walls get thicker and tighter the sheathing gets colder. Moisture that gets into the walls from air leakage or diffusion will condense on cold sheathing.
• OSB is almost a vapour barrier. It slows drying significantly.
• Air leakage from inside the house can deposit lots of water in the wall.
Better insulated walls have a higher moisture risk
Good sources of info• Building Science Corporation http://www.buildingscience.com/documents/
bareports/ba-1316-moisture-management-for-high-r-value-walls/view
• CCHRC report on Moisture in REMOTE walls
• Air tightness of older-generation energy efficient houses in Saskatoon in Journal of Building Physics Volume 36 Issue 3, January 2013 (email [email protected] for a .pdf)
High Density Spray Foam in a 2x6 wall
• R 24.8 (effective) for 2x6 24” O.C
• Less fussy
• Less labour
• Use less space
• Good air tightness with some remedial sealing
!
+!
-• Expensive
• No thermal break
• High embodied energy
• Less environmentally friendly- high GHG emissions from blowing agents
• Hard to renovate
• Not good for some small gaps
• Not as air tight as you would think
Riverdale Deep Wall!
• Lowest incremental cost to get R40+
• Follows normal construction sequence
• Can be very air tight
• Versatile
• Almost the same amount of dimension lumber as standard 2x6 @ 16” O.C.
• Minimal Waste
!
+• Extra labour
• Fussy air sealing
• Takes extra space
• Hard to renovate
!
-
Passive buildings need to have low thermal bridging.
• Both Construction Thermal Bridges and Geometric Thermal Bridges can be significant.
• At some point piling more insulation onto the surfaces doesn’t help much, and the joints and points need to be looked at.
©Passive House Institute US 2013 – Certified Passive House Consultant Training
and points need to be looked at.
7
Picture Credit: David White
Thermal Bridging Control• HOT2000 is responsive to thermal bridging control is a few
areas, but isn’t transparent.
• Effective R values depend on continuous insulation layers.
• Passive House Planning Package (PHPP) requires detailed input and gives good feedback on the consequences of thermal bridging.
• Eliminating thermal bridging will reduce heat loss substantially whether you can calculate it or not.
• Air tightness is by far the cheapest energy reduction investment you can make
• Air test results of 0.6ACH 50 or better are achievable in wood frame buildings.
• Keeping uncontrolled air leakage out wall assemblies enhances durability
• New vapour open air sealing products and techniques are one of the biggest benefits of the Passive House approach.
Windows
Courtesy of the US DOE
Windows and doors are the single biggest source of transmission heat loss - often 40% or more of the total building heat loss.
Window Shopping- features to look for
• Low conductivity (Low U value/high R value) glass
• High solar heat gain coefficient (on the south)
• Low conductivity (Low U value/high R value) frames
• Slim profile frames- typically the glass will have a better U value than the frame
• Low conductivity spacer bars
• Good airtightness- preferably triple weather stripping
• Durable
• A few large windows (less frame and framing) will use less energy and cost less than more small windows of the same total area.
Heat Recovery Ventilators
• Any air tight building requires a continuous supply of fresh air. Heating ventilation air can require up to 20% of the total heating energy
• HRV’s are an essential component of high performance housing
• Most HRV’s have relatively low efficiency. ( ~55 to 65%)
• High efficiency HRV’s (80 to 95%) are a good investment and have a short payback.
Total Annual Heating Energy Reduction(kWh/year)
Domestic Water HeatingCoolingLighting and Appliances*Net Annual space Heating
*Including passive solar and internal gains and heat pump C.O.P.
• Low flow shower heads
• Efficient Hot Water Tanks
• Water conserving dishwasher
• Water conserving clothes washer
• Grey water heat recovery
Domestic Hot-Water Energy Reduction
• Energy Efficient Appliances
• refrigerator
• clothes washer
• No Dryer
• Range/ Pressure cooker
• Energy Efficient Lighting
• compact fluorescents
• LEDs
• task lighting
• day lighting
• Energy Efficient Motors
• ventilation
• heating
• Phantom Load Control
• The Energy Detective(TED) monitor
Electrical Load Reduction
Riverdale NZ Heating Schematic
Solar Thermal Space Heating
7- Zen 28S Collectors
• Can be very expensive if you size it to meet a high percentage of the winter load.
• Not enough energy available when you need it most
• Can be very complicated
• Potential to harvest more useful energy per sq. ft than PV (~20 kWh/sq.ft./year)
• Incremental cost at Riverdale~ $50000 per unit
Fresh Air from
Outdoors
Exhaust Air to
Outdoors
Exhaust Air from Bathrooms &
Kitchen
Return Airfrom
House
Fan Coil
Heated / CooledAir to House
7 Solar Heating
Collectors
Domestic Hot Water
Domestic Cold Water from Mains
Drain Water Heat
Recovery
Electric Heating Element
Fan Coil Pump
2 THeatPump
Ground LoopsGL1. 41 m under garageGL2. 55 m around foundation
Daily Heat Storage Tank
Seasonal Heat Storage Tank
Tempering Valve
17,000 litreswater
300 litres water
Cold Waterto Interior
Uses
Heat Recovery Ventilator
Fan
Fan
Dwg M1. Riverdale NetZero House Mechanical Systems Layoutver 3d Drawn and developed by: David Morrow, Hydraft Development Services
Peter Amerongen, Habitat Studio and WorkshopMonitoring Instrumentation: Gordon Howell, Howell-Mayhew Engineering
Date: 2008 August 02
55°C to 80°C
5°C to 90°C6 GJ of heat
Fresh Air to House
Fan
Daily Storage Tank Bypass Valves
Fan Coil Bypass Valves
Seasonal Storage Tank Bypass Valves
Drainback Tank
30 litres water
Surface area:
21 m2
Cold Waterto Exterior
Uses
WM-cmWM-dh
Tsolar-in Tsolar-outTfc-in
Tfc-out
T1
T3
T4
T5
T8
House Temperature
Outdoor Temperature
T6
a
b V1
HX3
HX2
HX1
E1
V3a
V4 a
b
V5b
a
V7
a
b
V6 ab
P2
F1
F2F3
Fsolar
Ffc
HX4
Tempered Water to Showers
WM-cx
Solar Collector
Pump
P1
Solar SupplyHeat Meter
HM-ss
a V2
b
Vent
T2
c
V8
a
b
c
GL1
Daily Storage
Tank Bypass Valves
Seasonal Storage
Tank Bypass Valves
GL2
Heat Pump Pump
Fan CoilHeat Meter
HM-fc
b
Heat from solar collectorsSolar heat to daily tankSolar heat to seasonal tankPotable waterStored heat from seasonal tankStored heat to fan coilStored heat to daily tankStored heat to heat pumpConcentrated heat from heat pumpHeat to/from ground loops
Cold Water Pre-Heat
HX5
T7
Colour Legend for Heating Loops:
P3
Nearest Nuclear Fusion Furnace
Notes:1. Ground loops intended to provide space cooling only.2. Heat pump supplements the moving of heat if
required:a) from seasonal tank to fan coil by taking the
seasonal tank from 25°C down to 5°C;b) from seasonal tank to daily tank; andc) from fan coil to ground loops for space cooling.
3. Manual valve sets V7 and V8a) “a” is mainly used to create backpressure so loop
remains pressured while serving thenon-pressurised tank;
b) “a” & “b” are used for seasonal selection of ground loops for cooling;
c) “c” is for isolation only – it is normally open.
Net Zero in 10 easy steps
• Model the energy performance of your preliminary design
• Use the modelling results to optimize the building envelope and passive solar gain
• Reduce base loads
• Domestic hot water
• Lighting and appliances
!
• Consider Air Source Heat Pumps or Geothermal
• Size PV to meet remaining total loadEnergy Reduction
Renewable Energy Collection• Site assessment
• Preliminary design
• Optimize passive solar if available
• Finish detailed architectural and system design
• The energy harvested by Air Source Heat Pumps is 100% renewable - solar energy with no direct sun.
• It is possible to get C.O.P.’s* of 2 or better in Edmonton or Winnipeg.
• C.O.P. drops off as temperature get colder.
• Mitsubishi ‘Hyperheat’ units have shown C.O.P.’s of greater than 1.0 at temperatures as low as -30℃
• They can make or break the attempt to get to net zero energy.
0"
5"
10"
15"
20"
25"
30"
35"
40"
45"
50"
1" 13"
25"
37"
49"
61"
73"
85"
97"
109"
121"
133"
145"
157"
169"
181"
193"
205"
217"
229"
241"
253"
265"
277"
289"
301"
313"
325"
337"
349"
361"
Series1"
Edmonton Heating Degree Days 2013
Mitsubishi ‘Hyperheat’ cutoff (~-25℃)
*C.O.P. - Coefficient of Performance C.O.P. of 2 indicates 2 units of energy out for
every 1 unit of electricity in.
Air Source Heat Pump Operating Range
Heating and ventilating with a small mini split air source heat pump
*Needs EGH 86 or better envelope
Mini split outdoor unit
Fresh air fromoutside
Fresh air to house
Exhaust stale air out Mini split indoor unit c/w blower
Stale air exhaust from kitchen,
bathrooms and laundry
Transition supply duct
Controller to sync mini split fan with thermostat and post heater
10kW Thermolec Post Heater
HRV
12" round duct to supply heating and fresh air to house. 500CFM at < 0.36 in.WG
12 " return air from house
Mini splits vs Central systems
• Ductless mini splits can save heating system dollars if the loads are small enough to be met with point source heating and electric baseboard back up.
• Big central ASHP’s like the Mitsubishi Zuba Central will add ~$8000 to heating system costs.
• Even at that price central systems can pay for themselves in offset PV costs. For example, if it saves 3000kWh/year if will offset $10,500 worth of PV and also need less roof space.
Air Source Heat Pumps for Domestic Hot Water
• Relatively low cost $1500-2000 • Provide a small summer cooling
benefit • Work well in tandem with Air
Source Heat Pump or Geothermal heating.
• Will shrink the size of the PV array
• Annual COP of ~1.50 to1.75 is possible
• Provides a small amount of summer cooling
!
+!
- • Will increase winter heating load • Noisy
Photovoltaic Electricity (PV)
! • Requires lots of roof space- 100 sq. ft. to generate 1500 kWh/ year - more if you have shading
• Expensive ~ $3.00 to $3.50 per installed watt of peak capacity. Typical NZ system $30,000 to $40,000(Each installed watt in Edmonton will produce 1.1 kWh per year.)
• Supply is out of sync with demand - grid dependant.
!• Very simple installation, durable, almost no
maintenance • Can be added later if roof space is available • With grid tie it doesn’t matter that supply and
demand are out of sync. • “PV is a rock the makes electricity” Martin
Holladay
!
+
!
-
Mosaic Centre Case Study• New 30,000 square foot office building in south Edmonton
• Beautiful, healthy, nurturing, affordable place to work for the Mosaic Group of Companies.
• Headquarters for Oil Country Engineering Services Ltd
• Includes a daycare, co-working spaces, a wellness centre, and an incubator for other greener businesses
• Natural daylight in all work spaces.
• Project environmental goals
• Net zero energy
• LEED Platinum Certification
• Living Building Challenge
Process
• Energy modeller was hired before the architect
• Achieving the project goals using conventional fixed price contracting was going to be unaffordable
• Early commitment to Integrated Project Delivery
• Careful team building prior to design.
• Open documentation of project successes and failures. http://themosaiccentre.ca/
Mosaic Centre IPD
• Early involvement of key participants
• Shared risk and reward based on project outcome
• Joint project control
• Reduced liability exposure
• Jointly developed and validated targets
Bullitt Center
Mosaic Centre: In pursuit of Net Zero*
* For the whole report: http://themosaiccentre.ca/wp-content/uploads/2014/09/2013-06-13-ReNu-C3-Report-3.pdf
• More efficient servers and monitors
• Shaved lighting loads
• Reduced cooling load
• Utilizing waste heat from servers for heating
• Geothermal heating and cooling
• Higher efficiency PV
The IES run on versionC3 IES shows consumption for that design to be ~185,000 kWk/a. So they kept hunting. Solutions include:
• Project is under budget and 4 months ahead of schedule. Due to be complete in February 2015.
• There have been mistakes, a few of which would normally have been very costly and time consuming. The IPD team pulled together and corrected them quickly at a fraction of the expected cost.
• Premier quality, net zero energy building, being built at a premium of 5 to 10% over the cost of standard market space.
Results
• Savings from reduced lighting, heating and cooling loads did result in some reductions in equipment cost that have helped to pay for the envelope upgrades
Passive House • Started about 20 years ago when some Bo Adamson a German engineer
and Wolfgang Feist a physicist set out to reduce heating and cooling energy to a level (about a 90% reduction) that would be sustainable and leave room for the developing world to catchup.
• Building on the 1970’s work of Harold Orr (The Saskatchewan Conservation House) and William Shurcliff in the US, with stereotypical German thoroughness they built a heating and cooling demand spread sheet that accounted for everything.
• There are now ~30,000 Passive House buildings worldwide, several thousand in the US and a few dozen in Canada.
• Annual heating and cooling energy demand limited to 15 kWh/m²
• 0.6 Air Changes per hour
• 120 kWh/m² primary energy demand.
Passive House Metrics
Buildings designed and built to the passive house standard are among the most energy efficient, the healthiest, the most comfortable and durable buildings ever built.
The drive to meet this standard has powered innovation in building science, building techniques and building components. These innovations include:
• Very high efficiency HRVs
• Very high performance windows and doors
• Highly effective air sealing products and techniques
• Vapour open sheathing materials
• Highly insulated , thermal bridge free, vapour-open assemblies
• Hygrothermal analysis software
• Fine grained, detailed energy analysis tools (PHPP) now with a Sketchup interface
• House area is ~ 1600 sq. ft with a finished basement(TFA=246m2)
• 15kWh/m2 if .35 ACH50
• Thanks to Jim Zeibin and David Zeibin Architect
Cottonwood Passive House
U value w/m
R value
Concrete Foundation wall 0.113 50
Double stud exterior wall 0.076 75Truss roof 0.058 98Floor slab 0.119 48Windows InternormAir tightness target 0.3ACH50
HRVUltimateAir DX 300
Cottonwood Specifications
• Hard to meet the target with single family housing here in the frozen north, but your building will be better for the attempt.
• Multifamily is doable.
• PHIUS is about to roll out a climate specific standard, that will be more achievable here.
• Training: great courses available from CanPHI West and PHIUS