“… I’m an EE who likes to heat houses with solar air heaters (eg Dynaglass
“solar siding”) and/or low-mass sunspaces (eg 4’x8′ 10 mil HP92W 20-year flat
$1/ft^2 polycarbonate film pillows sealed with silicone caulk and gently
inflated with welding argon, via a tire Schraeder valve), with a 1000 Btu/h-F
car radiator or a MagicAire SHW 2347 duct heat exchanger that turns hot sunspace
air into 140 F water in an unpressurized tank that stores enough heat for 5
cloudy days, with a 1″x300′ NSF 125 psi HDPE or PEX 13-gallon pressurized pipe
coil with a 2 minute time constant in the tank to preheat water for showers.
On a cloudy day, 2 2-watt motorized dampers would let the radiator heat house
air with the tank. I stop simulating with TMY2 hourly weather data when a house
design wouldn’t need any space heating fuel in a TMY2 year, on paper.
Did you consider heating your house with a low-mass sunspace? You might add one
now, as you age, with less relish for wood cutting.
Ignoring direct gain,
86K/413 = 208 ft^2 of glazing could heat the house, eg an 8’x32′ low-mass
sunspace wall with 2 4’x8′ pillows in 2×6 structural frames for endwalls and an
8’x32′ R1 corrugated Dynaglass polycarbonate roof over 8 4’x8′ polycarb pillows.”
See original discussion at the SolarHeat Yahoo Group