Net Zero Energy on the Canadian Prairies

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 high levels of energy conservation

!

• 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

CANADA MORTGAGE AND HOUSING CORPORATION!

Riverdale NetZero Project — Edmonton, AB

Project Team Habitat Studio & Workshop Ltd. and Howell-Mayhew Engineering

CANADA MORTGAGE AND HOUSING CORPORATION!

EQuilibriumTM Housing Demonstration Projects

• 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

Habitat Studio Net Zero houses this year

Allen Residence

Shute Salvalaggio Residence Kennepohl Franchuk Residence

Kosowan Ferrero Residence

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).

• 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.

Effect Home Builders

Belgravia Green Net Zero Energy Home

• ~1600 sqft bungalow with finished basement

• partially shaded south facing site • Air source heat pump • Electric demand hot water • 12.5 kW photovoltaic system

Star Prebuilt Homes Ltd

NRCan R2000 Net Zero Energy Pilot• 13 projects representing all regions of the country

• Intended to demonstrate and prove the lessons learned following the CHMC Equilibrium Housing Initiative.

• Will test drive NRCan’s new Energuide Rating System and provide empirical support for Net Zero and Net Zero Ready labels that will be issued as part of the new R2000 program.

• The new R2000 standard comes in at ~EGH 86 which can get you to net zero with a reasonable amount of PV.

Key differences• A nifty spreadsheet for calculating new ERS numbers and verifying net

zero energy compliance.

• Simpler systems - fewer science experiments

• Air source heat pumps for heating and hot water.

• Net Zero Energy houses on sites with poor solar exposure.

“CHBA’s Net Zero Energy Housing Council (NZC) supports innovation in our industry with the goal of creating a market advantage for CHBA builder and renovator members who choose to pursue it. This will not only help to meet the housing aspirations of Canadians, but renew Canadian world leadership in high performance housing.”

In#alignment#with#the#CHBA#Strategic#Priority#to#Advance(Innova+on,#the#mandate#of#this#self;funding#ad;hoc#Council#is#to(deliver(services(that(will(support(members’(voluntary(adop+on(of(NZE.(#

The#NZC#will:#!  gather#intelligence#on#member#and#consumer#needs#to#inform#prioriCes#and#

influence#strategic#advancements,#!  build#awareness#and#knowledge#through#the#consolidaCon#and#sharing#of#

informaCon#uClizing#a#variety#of#channels#and#forums,#and#!  implement#acCviCes#to#idenCfy#barriers,#find#soluCons,#transfer#knowledge,#inform#

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CHBC$Net$Zero$Energy$Council$$

• Started in Canada and now North America wide • Great webinars at http://netzeroenergycoalition.com/connect/

webinars/ • Net zero energy housing is thriving in the US-especially California

where it will be a requirement in 2020. • A number of small US builders making a good business out of

doing mostly net zero energy housing • Some America’s biggest home builders -Pulte Homes, Toll Brothers,

Meritage, KB Homes are all delivering NZ homes. • US DOE Zero Energy Ready Homes- great source of info on how

to build and sell NZ houses.“Zero  energy-­‐ready  homes  are  the  future  of  American  housing.  They  have  to  be.  They  live  be;er,  help  to  protect  health  provide  luxurious  comfort,  work  be;er,  and  last  be;er  because  of  lower  maintenance  and  forward-­‐looking  construcAon  that  can  help  ensure  future  value.” -­‐Sam  Rashkin,  Chief  Architect  of  the  Building  Technologies  Office,  US  Department  of  Energy

63 | INNOVATION & INTEGRATION: Transforming the Energy Efficiency Market Buildings.Energy.gov

Lasts Better

Works Better

Lives Better

Advanced Technology

Ultra-Low Utility Bills

Engineered Comfort

Healthier Living

Quality Construction

More Durability

Black-Out Power

Water Efficient

Solar Ready

Long-Term Warranty

Disaster Resistant

Lower Cost Insur./Mort.

Zero Energy Ready Home Value

Other Benefits

• Market differentiation

• Makes you a better builder. Your houses will be

•More comfortable

•Healthier

•More durable

• It is worth getting in on the ground floor - This is likely coming anyway.

• Trust factor

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

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

House Shape

• Smaller buildings use less total energy and are cheaper to build

• Bigger houses often use less energy per square foot but more energy in total

• Simpler shapes have less surface area.

• Buildings with big cathedral ceilings and lots of dormers have more surface area

• Making small simple buildings look great can be a challenge

Providing room for renewable energy collection: As PV gets cheaper, finding roof space becomes the limiting factor

Riverdale NetZero

Mill Creek NetZero

Bonnie Doon NetZeroParkland NetZero

Windsor Park NetZero

NRCan NZ Pilot

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

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

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

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

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

!

-

Frost Wall Insulation

• 20 to 30% of total house heat loss can be from the basement.

• Basement walls should have almost as high R value as upper walls

• Very hard to add later

This thermal break has a great payback

4" of Type 2 EPS

Drainage layer for any condensation

'Smart' vapour barrier

• 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.

Draw an uninterrupted line around the entire thermal envelope.

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.

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 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 kind of 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"

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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

!

+

!

-

Envelope Specifications

FoundationR25- 2" EPS +R20 frost

wallR37- 4"EPS + R22 Frost

wallR52- 6" EPS + R28 Frost

wall

underlab insulation R9- 2" Type 2 EPS R18- 4" Type 2 EPS R27

WallsR 24 - 2x8, 24"O.C. R28

Batt R40- 12" Double 2x4 ,

24" OC

R67- 16" Double 2x4with 2x4 wiring chase,

Cellulose plus R14 roxul

Ceiling R60- cellulose R80 - cellulose R100- cellulose

WindowsDuxton fbreglass wih

R5.33/R8.33 COGDuxton fbreglass wih

R5.33/R8.33 COG~R 10 COG Passive House

windows

Air tighness1.5 ACH -Caulked poly

with Habitat details

.5 ACH - Caulked Poly with Siga tape and extra

care and attention

.03 ACH- Taped OSB, even more care and

attention, Passive house windows

Mechanical Systems

Heating systemLarge central air source

heat pump- Zuba CentralDucted mini split air source heat pump-

Electric baseboards

HRV VanEE 2000HE Air Pohoda Ultima 240E Air Pohoda Ultima 240E

Hot Water Air source DHW Air source DHW Air source DHW

ERS 82 ERS 88 Passive House

Labels/Third Party Verification

• Energuide

• R2000

• Builtgreen

• LEED

• Passive House

• Net Zero

• Net Zero Ready

• Near Net Zero

In a nut shell

1. Net zero energy building performance depends on an on-site photovoltaic (PV) system to generate the energy still required after conservation and any other renewables

2. Optimal solutions require shrinking energy needs and therefore the PV system so that:

1. You can afford the PV system

2. It will fit on your roof

3. Carefully designed conservation + an Air Source Heat Pump can shrink the required PV system to a manageable size.

4. Keep it simple! Insulation and air tightness will get you there. The science experiments either didn’t work well enough or were too expensive.

Tempted to try this?

• It is way easier the second time.

• Start by looking at houses that have worked in your climate zone.

• Let someone else make the mistakes.

• Take the Passive House Training- best investment there is in learning how to do ultra energy efficiency

• For more info on how to do practical net zero energy design and construction consider taking Marc Rosenbaum’s on line course at http://nesea.cammpus.com/courses/zero-net-energy-homes--online

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