re: roof spray cooling; are these calculations even close?
2 may 2001
>...r 30 in the ceiling...
so your 4k ft^2 140 f roof might add (140-80)4k/r30 = 8k btu/h, and
reducing the roof temp by to 110 f would save about 4k btu/h or 32k
btu over an 8 hour day...
>water here is about $1.5 / 1000 gal, so at 18 gal/hr, 12 hrs/day, it's
>about $8 per month. (or about 120kwh at current peak electric rates...
with a 3:1 cop, that 120 kwh can provide 360 kwh of cooling, ie 12 kwh
or 41k btu/day.
>any other suggestions?
fill your house with rocks and ventilate it with outdoor air at night,
and button it up during the day?