Transcript Retrofitting for Resilience Workshop

Retrofitting for Resilience
Workshop
April 13, 2013
Rosendale Recreation Center
Thank you
Manna Jo Greene
Deep Energy Retrofit (DER) … why?
• Fuel sources, therefore fuel prices are volatile, provides “hedge”
• Operating costs burden homeowners, money exits local economy
• Current weatherization/Home performance strategies
– (insulation placed between studs, 15% reductions, incremental benefit)
vs.
• Deep Energy Retrofit strategies
– (install insulation to exterior, air seal, reduce mechanicals, 65 – 75%
reductions, provides step function boost benefit)
• Benefits to preserving entrained energy of existing stock
Age of Existing US Housing Stock
Almost 60 million housing units built before the first oil embargo in 1973
Source: American Housing Survey 2005
© Marc Rosenbaum - EnergySmiths
Candidates for DER … both built within the past 20 years
Credit: Marilyn Kaplan
Credit: Tony Abate
There are several strategies for implementing a DER;
we have focused on the exterior insulation strategy for
the following advantages:
•Allows continuous, un-bridged insulation layer
•Facilitates exterior air barrier installation
•Can be installed while the home is occupied
•Thickness of insulation is not limited by wall thickness
•Eliminates the problems caused by blocking, bracing and other
internal framing elements causing missed (un-insulated) wall
cavities
70
Condensation Potential
60
50
50.5F - Dewpoint of 70F, 50% RH
40
41.1F - Dewpoint of 70F, 35% RH
30
27.7F - Dewpoint of 70F, 20% RH
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10
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Average temperature °F, Boston MA
80
Temperature gradient across a wall
70F
• Note that the temperature of
the interior face of the sheathing
is 20F – well below the dewpoint
of the inside air.
• If air from the inside reaches
the sheathing in any significant
amount, condensation will occur.
20F
• Air leakage through a small
hole can move 100 times more
water into a building cavity than
is transported by vapor diffusion,
so air barriers (AB) are more
20F
critical than vapor diffusion
retarders (VDR)
• With 2 inches of polyiso at R-13
the interior face of the sheathing
is 41F – little condensation risk.
© Marc Rosenbaum - EnergySmiths
70F
Foam (SPF) placed ON the wall is a strategy that
reduces thermal Bridging and improves nominal R
2x6 cellulose 18% wood
Nominal R21, Actual R = 15.8
77% of nominal R21
2x6 cellulose 18% wood 4” SPF
Nominal R45, Actual R = 41.0
90% of nominal R45
Credit: Marc Rosenbaum (Energysmiths)
Major Renovation Invokes Building Permit …
eliminates “kicking the can”
Air Infiltration Measurements
Change in Air Flow
20
ACH 50 from CFM Meas.
18
16
14
12
10
8
6
4
2
0
DRP1
ACH before DER
ACH after DER
DRP2
DRP 3_4
Deep Energy Retrofit Houses
DRP 34
MMBTU/unit & Heating Degree Days
120
7000
100
6000
MMBTU
80
4000
60
3000
40
HDD
5000
2000
20
1000
0
0
Before
DER
Total MMBTU
HDD
Average Total MMBTU / Unit
(4 Utica Houses)
35.0
30.0
MMBtu
25.0
20.0
26.1
15.0
24.9
20.6
10.0
13.6
5.0
3.8
2.4
3.5
1.9
10.8
7.6
8.7
3.8
5.9
0.0
Series2
Series1
Fall - Winter Months
'09 - '10 Before,
'10 - '11, '11- '12 DER
9.3
11.1
10.0
10.2
7.3
Underway … PON 2254, Exploratory Envelopes
• Develop repeatable strategies that scale
• Achieve following technical objectives:
– Whole house assembly, R > 25
– Total air leakage, < 0.25 CFM50 / ssf
– Labor & material / ssf = $10
• Combine strategies to optimize influence
• Acquire more data, 22 is more than 4, statistics
5 Building Science Contractors Selected, 22 homes
• Taitem Engineering (retrofit 4 houses)
– Snug Planet
• NAHB – Research Center (retrofit 3 - 4 houses)
– SIPA
• IBACOS (retrofit 8 houses, and 1 control)
– Green Homes America
• Verdae (retrofit 3 houses)
– Mulder Construction
• Levy Partnership (retrofit 3 houses, MF)
– Sto Corp
Material Intensive in both directions …
Reduced Mechanical Systems enables
substantial energy reductions
Continuous Mechanical Ventilation that works
Homeowner Engagement,
More Emphasis needed on promoting “comfort”
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Air quality
Safety (removal of auxiliary heat sources)
Insurance premiums (no ice damming, falling ice)
Building quality/integrity
Value the ‘resilience’ of the solution
Better sound attenuation (indoors is quiet)
Improves longevity of equity investment
Thermostat settings at occupant desired levels
Direct Benefits of Screwing 4” of Rigid to Exterior
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Works daytime, nighttime
Works summer, winter
Eliminates undesirable air leakage
Employs local labor
Invokes building permit, which brings house to code
Works when grid is de-energized
Works on cloudy days
Works when wind is not blowing
Long Ways away from a “Program” …
Allies to Educate
• Regulators
• Bank appraisers **
• Code officials, consistency
• Siding contractors
• Realtors
• Insurance underwriters
• Project agent
• Manufacturers discounts
• Slush fund investment to
code comply homes
Policies to help
• Carbon taxes
• Fuel oil taxes to fund Bldg
Science
• kBTu/ft2/yr threshold
• Reward for less
**
Contact…
• Greg Pedrick, C.E.M.
Buildings R&D Project Manager
17 Columbia Circle
Albany, NY 12203
(518) 862-1090, x3378
[email protected]
http://nyserda.ny.gov/advancedbuildings