Energy Performance in Northern MURBsMay 16, 2018

IntroductionWhy High Performance MURB?Examples of High Performance MURBs

Yukon / Northern BC First Nations Projects Champagne & Aishihik First Nation (water supply,

hydropower relicensing, ground source heat pump) Taku River Tlingit First Nation (hydropower) Dease River First Nation (solid waste management) Daylu Dena First Nation (water supply, solid waste

management) Little Salmon Carmacks First Nation

(water/wastewater) Liard First Nation (solid waste management) Teslin Tlingit Council (hydropower) Old Crow Community Centre (Building Energy) Photo: Bryan Evans – Taku River, just below King

Salmon River

Northern Challenges

Centre for the North (an initiative of theConference Board of Canada) highlighted anumber of challenges with northern housingin its 2012 report:

Logistical challenges with a short shipping season and long distances Lack of housing-related infrastructure, such as piped-in water and sewer High construction costs (e.g. Nunavut is three times higher than Southern Canada) Adverse weather conditions Housing affordability (81.5% of households face affordability problems) Lack of skilled tradespeople and increasing reliance on the south Housing maintenance; rate of disrepair is 2.5 times higher than the south

What is a High Performance MURB?

Reduced energy operating costs

Energy security

Improved thermal comfort andhealthier indoor living environment

Resiliency against effects of powerfailures

Reduced GHG emissions toaddress climate change impacts

Improved durability and reducedneed for maintenance

Inuvik Singles ComplexMore than 50% better than NECB (code)Key energy conservation measures: Reversing flow HRVs (95% effective) LED Lighting Well-insulated envelope Condensing gas-fired boilers serving in-floor

radiant heating High efficiency hot water heaters Low-flow showerheads and faucets Vertically mounted solar PV panels

Iqaluit 33-PlexKey features include: High performance glazing relative to

code (vinyl-framed triple glazed) High-efficiency oil-fired boilers Fully ducted HRV for each suite Energuide-rated appliances LED lighting Low flow plumbing fixtures

Grass Creek North Phase 1 Three-storey 20-unit wood-framed apartment building

located in Anchorage, AK that achieves 6-Star efficiencyrating Key features include: High performance glazing (low-E triple glazed with

thermally broken aluminum frames) High-efficiency gas-fired condensing boilers (95%)

serving hydronic baseboard heaters Programmable thermostats LED lighting 61 roof mounted solar thermal collectors and 42 kW

solar PV system Air-tight construction (1.4 ACH at 50 Pa)

Front Street Seniors Housing, Whitehorse

48-unit seniors housing complexKey features include: Well-insulated envelope (R-60 roof, R-40

wall, R-40 floor) High performance glazing (triple-glazed,

two low-E coats, vinyl frames) Electric baseboard heating (also saves on

maintenance costs) Individual suite HRVs (76% effective) ENERGY STAR rated appliances

Building Envelope

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NECB 2011 Varnamo Ostersund Sisimut Goteberg Karl Johansvag

Sems Have JärvenpääZero Energy

House

Fort Liard Inuvik

Ass

embl

y R

-Val

ue

Ground Roof Wall Window

Metrics of Performance% Better than code (NBC / NECB)

EUI – Energy Use Intensity (kWh/m2.yr) Lower overall energy use and utility costs

TEDI – Thermal Energy Demand Intensity (kWh/m2.yr) Ensure buildings have better envelopes that save energy and

improve resilience

GHGI – Greenhouse Gas Emissions Intensity(kgCO2/m2.yr) Encourage low-carbon fuel choices and reduce building emissions

City of Whitehorse / CMHC Requirements City of Whitehorse Prescriptive Requirements: R28 Walls, R60 Roof, USI-1.4 Windows,

1.5 ACH (50 Pa), 65% effective HRV Applies to all new construction

CMHC Threshold for: Affordable Rental Innovation Fund – 10% better than NECB National Housing Co-Investment Fund - 25% better than NECB

BC Step Code Targets

Riverdale 8-Plex Two-storey 940 m2 (10,120 ft2) building constructed in 2010 in Whitehorse,

YK for the Yukon Housing Corporation Common ground floor entry area leading to four single level units on each

floor Ground: Four 1,018 ft2 (95 m2) x 2-bedroom units First Floor: Two 1,310 ft2 (122 m2) x 3-bedroom units, Two x 2-bedroom units

Energy performance previously analyzed using construction documents,utility billing data, sub-metered electrical data, environmental monitoringequipment, and energy modeling.

Riverdale 8-Plex Floor Plan

Energy Performance

Source: M&V of Heavily Insulated Yukon Housing Construction, RDH Building Science

What is an Energy Model?

Workshop Energy Model Development Riverdale 8-Plex used as a template MURB design for optimization Energy Model developed using operational data from the M&V study and

running multiple scenarios for the following key input parameters: Shape Factor Window-to-Wall Ratio by Orientation and High SHGC Wall R-Value Roof R-Value Window U-Value Heat Recovery Effectiveness/Frost Control Air-tightness (ACH) Plug Loads Domestic Hot Water Loads Heating System

Energy End Use BreakdownTotal Area 938 m2Occupant Density 3.25Heating Set Point 22Heating Set Back NonePlug Loads 5 W/m2Lighting 6 W/m2Ave. Daily DHWConsumption 210 L/unit/dayAbove Grade R-Value 46 (hr-ft2-F/Btu)Roof R-Value 75 (hr-ft2-F/Btu)

Slab on Grade R-Value 20 (hr-ft2-F/Btu)

Window U-ValueFixed - 1.1 W/m2KOperable - 1.6 W/m2K

Window SHGCFixed - 0.27Operable - 0.22

Window to Wall Ratio 14%Infiltration Rate 1.24 ACH at 50 PaHeating Electric baseboardsCooling NoneVentilation 75% effective HRV

Domestic Hot Water Electric tank-type, 3000 W/unit

Lighting, 12,776, 12%

Plug Loads,17,776 , 16%

Fans, 5,399 ,5%

Domestic HotWater, 37,621 ,

34%

Space Heating,35,796 , 33%

Modelled EUI: 117 kWh/m2 Measured EUI: 140 kWh/m2 Possible Reason for Discrepancy: Air-Tightness Assumption

OrientationMassing and orientation in energy-efficient MURBsdriven by passive solar design principles:

1. Site Selection - Select a site with good solar access

2. Orientation - Positioning of the building’s long axis towardsolar south

3. Window Sizing and Placement – Minimize window sizingin northern elevations and maximize in southernelevations

4. Shading - Configure shading devices, such as eaveoverhangs or external shading devices to permit lowwinter sun into building and high summer sun out

City of Iqaluit, Plateau Subdivision- Orienting 70% of windows in asouthern direction resulting in 1%energy cost reduction

Massing and Shape Factor The compact MURB typology is inherently more efficient Less (thermal envelope) surface area means less surface area for heat to

escape through Aim to minimize the ratio of exterior surface area to floor area

Building EnvelopeMultiple options modelled for wall assemblies R-25 R-35 R-45 R-60

Inuvik Singles

Riverdale 8-Plex

Window PerformanceOptions Modelled USI values of 0.8, 1.0, 1.2, 1.4 and 1.6 Option of optimized window strategy (30% WWR on south with 0.4

SHGC, 7% on north)

High performance quad-glazed IGU from Yukon-based NorthermWindows and Doors

Heating System Options Electric baseboard heaters ($0.16/kWh of

heating) Powered by clean Yukon electricity, minimal

maintenance

Oil-fired furnace ($0.12/kWh of heating) Higher GHG emissions, more maintenance, not 100%

efficient, fuel transportation and storage

Cold Climate Air-Source Heat Pump ($0.10/kWhof heating) More efficient alternative to electric BB Can operate down to -20C Energy model indicates seasonal COP of 1.5 in

Whitehorse climate

Air Source Heat Pump Performance

Source: NRCan Cold Climate Air Source Heat Pump Pilot

Heat Recovery Ventilation

Effectiveness ranges from 65% up to 90% Frost control strategies: Exhaust-only (increased infiltration) Recirculation (reduced ventilation/air quality) Electric pre-heat coil

Modelled Options: 65% effective, 0C preheat 75% effective, -5C preheat 90% effective, -10C preheat 90% effective, dual core reversing HRV

(no preheat required)

Domestic Hot Water, Plug and Lighting Drain water heat recovery and low-flow

fixtures results in 30% reduction in DHWload Equivalent to annual cost savings of over

$250/unit, payback under 3 years

Energuide-rated appliances and highefficiency LED lighting results can provide25% reduction in plug load at minimalincremental costs

Renewables Yukon PV Generation Potential: 900-1100 kWh/kW Riverdale 8-Plex Footprint: 80 kW rooftop PV Annual Cost Savings: $13,700 ($0.16/kWh) Simple Payback: 17.5 years ($3000/kW)

The Challenge with Modelling

The typical way to model is totest a single variable one at atime, and adopt the ones thatmake sense.

The problem with this approachis that as we adopt changes,previous tests become invalid.

Testing Multiple Variables

North Facing Zone

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-20

-10

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Air

Tem

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(deg

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Outdoor Air TemperatureSuper-Insulated EnvelopeSuper-Insulated Envelope with High SHGC WindowsCity of Whitehorse Code Compliant MURB

South Facing Zone

-40

-30

-20

-10

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Air

Tem

pera

ture

(deg

C)

Outdoor Air TemperatureSuper-Insulated EnvelopeSuper-Insulated Envelope with High SHGC WindowsCity of Whitehorse Code Compliant MURB

Recommended Design StrategiesMinimize VFARMaximize high SHGC windows on southern orientation,

minimize WWR on the north Target optimal levels of R / U values for walls / windows

(diminishing returns)Highly effective HRVs with minimal pre-heat for frost controlEnsure construction of air-tight assembly – big impact on

energy performance in the northConsider alternative electric-based heating energy systems

(cold climate air source heat pump w/ electric BB back-up)

Shape Summary

Imapct of Building Envelope

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City of Whitehorse Code Baseline Envelope High Performing Window-WallBundle w/ Baseline Infiltration

(1.25 ACH)

EU

I/TE

DI (

kWh/

m2)

Impact of Window and Wall Performance on EUI and TEDI

TEDI

Impact of Air Leakage

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City ofWhitehorse

Code

BaselineMURB - 0.6

ACH

BaselineMURB - 0.8

ACH

BaselineMURB - 1.0

ACH

BaselineMURB - 1.25

ACH

BaselineMURB - 1.5

ACH

BaselineMURB - 2.0

ACH

BaselineMURB - 2.5

ACH

TED

I(kW

h/m

2)

Impact of Air-Tightness on TEDI

TEDI

Heat Recovery

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City of WhitehorseCode

65% / 0C 75% / -5C 90% / -10C 90% / No PreheatCoil

EU

I/TE

DI (

kWh/

m2)

Impact on Heat Recovery Effectiveness and Preheat Coil Temperature on EUIand TEDI

TEDI

Performance Package Bundles