Back in January I took the Passive House Training at Yestermorrow Design/Build School. I carpooled to Warren with Malcolm Grey of Montpelier Construction. I was telling him about how I was planning to redo my roof and insulate it while I was at it and he suggested I enroll in Efficiency Vermont's Home Performance with Energy Star program with the possibility of getting some money to help pay for it.
So I couldn't refuse that.
I paid Malcom $400 to audit my home and find issues including an air leakage rate of 4500 CFM50 for a 1300 sqft home. Thats 26 air changes at a pressurization of 50 pascal. About what you can produce by holding your lips and inflating your cheeks. Try it.
I then stripped my roof, fixed the rotten areas and filled the holes where the fiberglass was missing from animals and poor installation. Then I applied 4" of insulation with an airtight membrane (Proclima) that I taped together. I applied polyiso foam on one side and mineral wood on the other to compare. I found that I could get the mineral wood tighter because it was squishier but could tape the foam creating redundant layers of air tightness. It was easier to cut the mineral wool as well. The mineral wool was slightly more expensive depending on your source. Other than that installation was very comparable. In this process I cut off my overhangs and wrapped the edge of the roof about 12". Strapping went on top with roofing on that.
I also put 2" of mineral wool on the ext. of one gable end that needed residing and blew 4" of cellulose to the interior of the other gable end that was framed to the inside. I added dense pack cellulose to 36sqft of area that was exposed from an old chimney and filled the top of the first floor wall cavities at the rim joist, filling a couple half way where electrical wiring was installed and the cellulose was either removed or not added.
On top of insulating I air sealed some glaring spots including the cupola hatch,the garage bay doors, the exhaust vent for the on demand heater and two windows. There was a lot more I can still do.
Upon retesting I got my air leakage down from 4500 CFM50 to 2600! That is an improvement of 42%.
35% was my goal for the incentive on top of 75¢/sqft of insulation with a cap of $2500.
TOTAL Estimated %
Heating Energy Savings:75.31 %
Estimated annual savings: $704.96
Estimated annual heating MMBTU savings: 73 Estimated annual CO2 savings in lbs: -912
I usually use 2-3 chords of wood for heat and hot water and 100 gallons of kero for backup heat and hot water.
I am excited to see what next year's usage is!
Thanks Efficiency Vt and Malcom.
Saving money is an incentive to making my home for efficient. Even for an energy geek builder like me.
Friday, June 1, 2012
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