Shawna henderson_nshba_trc_oct2010

Deep Energy Retrofits"

Shawna Henderson, CEO"Bfreehomes Design Ltd."

Energy Efficiency programs aim for a 20 to 30% reduction in space and water heating needs."A deep energy reduction aims for 50 to 90%."

12 house types, 6 cities"

Range of ages:"1922 to 2000"

1. "How does house type/age affect NZEEH?"

2. "How does climate affect NZEEH?"

Approaching Net Zero Energy in Existing Houses"

13.2 million existing homes in Canada, approx 98% of overall housing stock"

"Nova Scotia: nearly 50% pre-1970"

Halifax: dwindling land resources in city, increasing sale prices"

"Situation!

Higher energy prices, older houses: OPPORTUNITY TO GO DEEP"

Challenge"Qualified trades, Financing"

1” type 4 foam on 2x4 walls = Lost Opportunity R10 or R12 + R5 = R15 to 17 "

(vs. new code R24 min … what does resale look like in 5 years?)"

3” foil-faced polyiso as ext air barrier: "R10 or R12 + R18 = R28 to 30"

Don’t be tempted by the low hanging fruit!""

House Yoga – Flexibility & Endurance""

Where is dew point?"What is first condensing surface?"Small extra cost vs. big energy savings?"

Ceiling Main Walls ExposedFloors

BelowGradeWalls

Slab

Vancouver 10.6 (60) 7.0 (40) 7.0 (40) 7.0 (40) 1.8 (10)Calgary 14.4 (80) 10.6 (60) 10.6 (60) 7.0 (40) 1.8(10)Toronto 10.6 (60) 7.0 (40) 7.0 (40) 7.0 (40) 1.8 (10)Montreal 14.4 (80) 10.6 (60) 10.6 (60) 7.0 (40) 1.8 (10)Halifax 10.6 (60) 7.0 (40) 7.0 (40) 7.0 (40) 1.8 (10)Whitehorse 14.4 (80) 10.6 (60) 10.6 (60) 7.0 (40) 1.8 (10)

Approaching  Net  Zero  Energy  in  Exis4ng  Houses    

Upgraded  Envelope  Targets  (RSI/R)    Averages from superinsulated houses built/designed in the last 5 years

in Canada and northern US, incl. EQuilibrium House Initiative projects

Assumptions we can challenge"

The diminishing returns on insulation limit thermal envelope improvements""Windows have crappy performance"

Canadian houses need full-size, central heating systems"

Energy availability and low prices will remain stable, so it’s business as usual"

Renovation Pyramid"

The Envelope, Please!"

Doors, windows replace/repair/retrofit""Lower envelope requirements = "Lower energy needs = "smaller space conditioning requirements"

Focus on draftproofing, then insulation""foundation up"

Space    65%  

Water  17%  

Appliances  13%  

Ligh4ng  5%  

As  Is  

Space    57%  Water  

21%  

Appliances  16%  

Ligh4ng  6%  

Conven*onal  

Space    33%  

Water  8%  

Appliances  46%  

Ligh4ng  13%  

DER  with  Solar  Thermal  

Shift the relationships between purposes and energy use""

0  

50  

100  

150  

200  

250  

300  

350  

400  

As  Is   Conven4onal   DER  with  solar    

Energy  Use  Comparison  

Ligh4ng  

Appliances  

Water  

Space  

50%  reduc4on  

80%  reduc4on  

Meeting DHW load becomes becomes bigger challenge than space heating as envelope improves"

#1: get rid of water problems"

A: No direct contact w/concrete or masonry walls or floors for moisture sensitive materials"B: Moisture tolerant materials are not in contact with materials that will absorb water if there is problem"C: Airtight construction on foundation walls and floors warms first condensing surface, mitigating moisture issues in living space"

Plumbing and electrical services run in front of 2 lb foam insulation and behind standoff wall – full depth insulation throughout basement and header area"

#2: don’t invite them back"

Above-Grade Insulation"‘flash and batt’ interior strap-out or standoff"

Min. 2” layer of 2lb foam for air barrier"

!!! HEADER ALERT!!!"

"

Biggest issue: DER with exterior insulation can make wall more vulnerable to leaks and damage" Especially at

attached shed roofs "

Especially with windows above"

Especially in areas prone to horizontal driving rain"

Picture from BSI presentation at ACI New England 2010: Windows: i.e., The Holes in Your Wall

OMG!!! BFFL!!!The Whole House Drainage Plane"

Illustra4on  from  www.buildingscience.com  

Another Bestie:"Pan Flashings"

Outies Rule!"Extended ½” ply window bucks flush with 3 to 4 inches of exterior foam"• Simpler drainage plane connections and geometry"• Lower cost (extra trim is interior material – we use drywall)"• Similar appearance to original, tie in w/neighbourhood"

Innies:"Window is in same plane as original wall"• Perhaps greater protection from wind-driven rain from inset"• Some additional solar shading"• Can use existing window trim"• If windows are not going to be replaced, what choice?"

Pic

ture

s fro

m B

SI p

rese

ntat

ion

at A

CI N

ew E

ngla

nd 2

010:

W

indo

ws:

i.e.

, The

Hol

es in

You

r Wal

l

5- year payback based on $ spent vs. energy savings not the whole story – how to quantify comfort?"Windows, siding = ‘permanent’ components w/20 yr planning horizon"

Comfort Envelope = Thermal Envelope"

Inside glass temp affects rate at which occupants radiate body heat to the glazing. "

It also impacts condensation and moisture issues in a house as envelope is improved."

Mechanical ventilation required in DERs "

With low space heating loads: can we use ventilation system to distribute heat a lá PassivHaus?"

Window Comfort 1"

4 factors:"Air Temperature"Mean Radiant Temperature"Relative Humidity"Air Movement"

Window Comfort 2"

Mean Radiant Temp/"Air Temperature"

Air Movement/"Relative Humidity"

OK, 5:"Proximity"Where are you comfortable?"…1’ …2’ …3’ …4’ from wall?"Cuts down on useable room size to stay comfortable – forget issue with thick walls!"

Thermal Envelope shortcomings can be fixed by improving equipment efficiency""Comfort Envelope shortcomings leave complaints, customer dissatisfaction and"increased energy expense and pollution because of higher thermostat settings.""Work with Thermal/Comfort Envelope."

Thermal/Comfort Envelope"

From this …"

… to this "(reasonable facsimile of system)"

97% efficient, 50k Btu natural gas condensing boiler augmenting solar thermal system "DHW and space heating delivered via dual-coil, 120 gallon storage tank"

Two of each:""60% efficient, 120k Btu oil boiler ""80 gal. electric water heaters + indirect tank, uninsulated in unconditioned space"

Oh, ya, mechanicals…"

From monster cast iron rads EVERYWHERE to infloor radiant at 12 and 16 inch o/c"

From high-temp hydronic baseboards EVERYWHERE to a

few wall-hung low-temp rads"

House as an Investment"

Define investment period"What’s in your pocket at the

end? ""

Alternatives …"Scenarios for house"Scenarios for money"

Resale-ability?"Non-energy benefits?"Investment horsepower?"

What makes us tick?"

Spending decisions NOT based on bottom line:"– Comfort, safety, peace of mind"– Personal goals"– Ego gratification"–  Justification leads to cherry-picking"– Community leadership"DRIVERS ARE NON ENERGY BENEFITS"

Value of Non-Energy Benefits…"…to utility

Transmission /distribution savingsPeak load restrictionsReductions in arrears and late payments/write offs/bad debtReduced regulatory costs and discount paymentsReduced emergency service calls"

…to societyEconomic impacts (job creation/tax revenue)Improved housing stock/preservation Emission/environmental impactsHealth and safety benefitsWater and wastewater savings"

"

What do all of these benefits have in common? "

They can be quantified."

How does the Homeowner/Ratepayer Gain from Non-Energy Benefits?"

Financial"Comfort"Aesthetics"Health and safety"Noise reduction"Education-related"Convenience"

What do all of these benefits have in common? "

Except for #1, they are difficult to quantify objectively."

Broader, clearer financial analysis"

Financial analysis does not begin and end with payback on a product – Return on Investment (ROI) is clearer indicator of how and where clients can best spend their money"

EE Investment/Energy Costs"Oil " "$8,100"Electricity "$7,300"Nat Gas "$4,000"

Conventional: $22k"

Deep Energy Retrofit: $37k"

DER w/solar combi: $52k"

Oil " "$5,100"Electricity "$4,600"Nat Gas "$2,600"

Oil " "$2,100"Electricity "$1,900"Nat Gas "$1,000"

How to Frame the Analysis of Return on Investment for Energy Savings Measures"Among the practical range of investment decisions:""

"Which provides the largest “return”?""Which are in your budget range?""Which achieves the desired returns within investment timeframe?""""What non-energy benefits are driving your decision?" e.g., comfort and aesthetic benefits, health and safety, greater control over energy use, ease of selling home, enhanced pride and prestige, environmental responsibility"

"

If this, then…

If this, then…

If this, then…

Where you are

Where you’re going

Phases and Roadmaps"

If this, then…

If this, then…

Building Critical Mass:increased demand

+ stable,

qualified work force"