Hello, thanks thus far.
No cooling required, house will be at 8,800' altitude, in a Zone 5 county right next to Park county which is Zone 6. Average year temperature is 40* acording to Teller Co.
I agree 100% that the most important factors to address are insulation & infiltration.
It's biggest heat loss is the large East facing windows on the great room / kitchen. I want alot of morning sun in there + it faces Pikes Peak, but lots of trees on neighbors property block most of view.
Roof will be about R51, vented 9:12 pitch, 3" polyiso + 11.5" dense packed cellulose, Roofing is already bought Decra steel shake dark green.
1/2 will face South, but I am reluctant to put holes in it to mount PV panels.
Walls will be 8" ICF about r23, gable ends above ICF about r40. 3" polyiso on exterior + synthetic stucco with drainage plane. Stud wall: 2x6, 24" OC filled with dense packed cellulose.
Under radiant slab will be 8" of type 2 EPS. FPSF (frost protected shallow footers) insulated on exterior with 8" type 2 EPS. AFI = 2,500
I'm limited to R28 below slab, as not enough heat would be released to keep shallow footers 16" from freezing below, acording to building code.
Heat loss at design temperature of 2* is about 6 btu/ft2 depending on wind.
Which is pretty good. Many believe that Passive House standards are overkill.
Solar storage will be VERY well insulated with 12" EPS + pearlite at corners inside foam cube between round tank & foam.
Useful stored heat between 80* - 35*
45* x 1000 gal. x 8.3# / gal = 373,500 btus.
I think this is worth using with heat pump.
Also the panels will gain more heat in this range than when they get hot.
BBP
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