getting unrealistic numbers for blower door
I found a great deal on a retrotec 2200 blower door kit about 4 years ago. I finally used it yesterday.
specs:
-3200 sq ft 1.5 story house
-cathedral ceiling with closed and open cell foam insulation
-walls are flash and batt 1.75″ closed cell foam and r13 fiberglass insulation.
– 34000 ft3 volume
-ducted mini split heat pumps with ducts in conditioned envelope, since insulation is at the roof
-all visible penetrations sealed
-all electric house
-moved in in 2023
but, I have 28 builder grade single hung windows that i assume are leaky
I anticipated the air leakage rate would be 5 ach50 to 7 ach50 but i’m getting 1.45ach 50 (838 cfm ).
I feel this is an impossible result with so many single hung windows
Is it possible to have such a low ach50 with so many operable windows?
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Replies
Single hung windows typically leak less air than double hung windows since there are fewer sealing surfaces. Inoperable fixed windows have less air leakage than single hung windows for the same reason.
That is a good result on your test. I'm not sure there would be any way to confirm the readings other than to have a test done by an independent third party with their own equipment.
you're right. I would have to pay $250 for an independent test and I'm not sure I care enough.
my energy consumption is very low- averaging 1300kwh a month since I moved in, so Im not too worried about it.
Thanks for the input!
According to this website (https://www.constellation.com/energy-101/energy-education/average-home-power-usage.html#:~:text=Average%20kWh%20usage%20per%20square,per%20square%20foot%20per%20month) the average energy consumption in the US is 0.49kwh/sf for a residence. For your residence that would be 3200*0.49=1,568kwh so you're below the national average it appears so it looks like you're doing something right. Good job.
that's good to know. I think my consumption might even me much better than average since my house is all electric, and I have a well and septic system that use about 95-100 kwh a month.
thanks
If you're done with it can I have the blower door setup?
lol. awesome question :D I still have a mother in law house to build so it may be a while
so I just had a realization . I believe that code minimum for new construction windows is 0.3 cfm per window??? or is it per square foot of window area?
edit: its 0.3 cfm per square foot - I have 620 sq ft of operable windows so if the windows are at least code minimum then im adding 186 cfm from window infiltration. not as bad as I thought