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re: where can i find?
25 may 1998
laren333 wrote:
>nick, it's nice to see someone wielding numbers again.
gladja liked 'em, laren :-)
>...my old "stack effect" formula seams to drained right outta
>my head somehow.
cfm = 16.6 av sqrt(h dt), found in various forms in the ashrae handbook
of fundamentals, bill yanda's "food and heat producing greenhouse," and
the 1990 "passive solar energy" book by bruce anderson and malcolm wells.
i still think pools need better performing, more trendy "solar covers."
a large flat foamboard titanic that automatically floats at night, sinks
a bit when the sun is shining, and sinks to the bottom for swimming? or
maybe a flat u-boat, with klaxons.
or something for the 4' tall x 24' diameter $1099.99 above-grounder from
water warehouse (1-800-574-pool), say 10 4'x8'x 2" thick vertical perimeter
pieces of foam tucked under the liner, kerfed outside so they can bend,
another 14 4'x8' sheets for the top, with a layer of poly film over them,
then some sand for ballast and solar absorption, then another layer of poly
film to reduce evaporation, then some pvc pipes to float it. about $500,
to lower the pool's conductance to about (450+300)/r10 = 75 btu/h-f and
collect about 610(450)0.9 = 247k btu/day in january where i live, so
247k = 24h(t-30f)75, and t = 167 f, ideally.
if we kept it at 85 f, it would lose 24h(85-30)75 = 100k btu on a cloudy
day, cooling by 100k/(15k gal x 8 lb/gal) = 0.8 f.
nick
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