re: passive solar cooling in the desert
19 sep 2004
anthony matonak wrote:
>the panels from this maker don't appear to be finished on either side.
>they are simply a sandwich of two pieces of osb with foam in the middle.
so, they look like flaked wood.
>typically a builder would add drywall to the inside and some form of
>siding (or roofing, as appropriate) to the outside. you get to choose
>whatever siding and roofing products you like.
including paint on the outside and varnish inside (suggested by code-compliant
doug kelbaugh, dean of the u mich architecture school :-) and hinged hole
cutouts for doors and windows. good paint might last a long time in a desert.
the roof might be epdm rubber, with shallow licl lakes separated by dry epdm
beds to act as water collectors and parasitic air heaters, like this, viewed
in a fixed font like courier:
| 2' |
poly s nate
flat p clear
clear a flat
c poly nate...
epdm licl r lake epdm dry bed epdm
epdm 2x4 epdmepdmepdm 2x4 epdmepdmepdmepdmepdmepdmepdm 2x4 epdm
--------------------------------------------- top of sip ------
a tight sip house in an average 85 f humid place like miami or brownsville,
tx (with a 75.7 daily min and w = 0.0176) might only need 15 cfm of fresh air
with 1000x15x60x24hx0.075(0.0176-0.0120) = 9k btu/day of dehumidification
and 24h(85-80)300 = 36k btu/day of cooling to reach the 80 f/w=0.012 upper
right hand corner of ashrae's comfort zone. the cooling might come from an
indoor greywater wetland or some night air, with internal house mass.
how many square feet of 80 f licl solution (precooked to 160 f) are needed
to remove 9 pounds of water from 80 f house air with w = 0.012 in 12 hours?