re: help is here!
25 jun 2000
dr. jennifer eiserman & terry reynoldson wrote:
>thank you for your [emailed] in-depth explanation.
you are welcome.
>i understand everything except the purpose of paragraph #1.
>> >i have heard of an architect in sydney who asked one of our leading solar
>> >designers which side of the house should he put the solar greenhouse...
>> >he thought south was "better"...
that's about architectural ignorance. north is better in sydney, australia.
>now then...how would you classify our lite-form® system?
>it has 2" of high density extruded polystyrene foam (xps) on both the
>inside and outside of a concrete wall...
seems better to leave the foam off the inside, so the concrete can
store passive solar heat. then again, some say concrete isn't green.
hollow blocks might work better, if there's a way for room air (and
dust...) to move inside them. passive solar houses tend to have large
day-night temperature swings unless they have lots of thermal mass
with lots of surface, especially if the solar heat arrives as warm
air from a low-thermal mass solarium (which can desirably stay cool
at night and on cloudy days without robbing heat from the living space.)
>the insulating performance is equivalent to a framed wall insulated to r-50
i'd say the 4" of beadboard is r16, not r-50. i've seen this "effective
r-value" nonsense before, eg on the monolithic dome website. you might
make an argument for it on a day when it's 80 f during the day and 50
at night, in a house that would otherwise need both ac and heat over
24 hours, but not over a long cold winter, when the outdoor temp is
mostly below the indoor temp. then it's r16.
>the outside surface may be cladded with dryvit outsulation® which
>collects solar energy
what? the dri-vit i know doesn't collect solar energy... it has a
sol-air temp like anything else, eg vinyl siding, but i wouldn't
honestly call it a collector.
>and conducts it to the interior in a slow, consistent manner (
with a magical ***flywheel*** effect? :-)
>savings in heating costs offset expenses within a couple of years...
i'd evaluate something like this on the basis of yearly fuel cost
and consumption, vs "savings." how's it compare to r2000. what do
those guys think about "effective r-values"?
>personally, i would not call this a "traditional trombe wall".
i read about "a mass wall behind glass" on your website, but this
sounds different (and a bit hair-brained to me :-) i'd be happy to
try to see the light your way (or help you come up with something
better) using some basic physics, with numbers.