Article 31356 of alt.solar.thermal: Path: news.misty.com!not-for-mail From: nicksanspam@ece.villanova.edu Newsgroups: alt.solar.thermal Subject: Re: Plug-and-play sunspace house and water heating Date: 28 Sep 2008 18:02:32 -0400 Organization: Villanova University Lines: 22 Message-ID: References: NNTP-Posting-Host: acadia.ece.villanova.edu X-Trace: max.inside.misty.com 1222639354 9838 153.104.44.130 (28 Sep 2008 22:02:34 GMT) X-Complaints-To: abuse@misty.com NNTP-Posting-Date: Sun, 28 Sep 2008 22:02:34 +0000 (UTC) Xref: news.misty.com alt.solar.thermal:31356 >... 750 Btu/ft^2 falls on the ground and 1030 falls on a south wall on >an average 29.7 F January day with a 43.2 F high in Boulder. So a well- >insulated house with a 200 Btu/h-F thermal conductance and no window or >internal heat gains would need 24h(65-29.7)200 = 169K Btu/day of heat, >or 847K for 5 cloudy days in a row. > >A 1000 Btu/h-F radiator with water temp Tmin (F) could keep the house 70 F >if (Tmin-70)1000 = (70-29.7)200, which makes Tmin = 78 F. If a heat storage >tank contains P pounds of water at 140 F on an average day and (140-78)P >= 847K Btu, P =3D 13661, ie P/62.33 = 219 ft^3 of water, eg a 3'-tall >x 219/3 = 73 ft^2 tank, eg a 3'-tall x 9.6'-diameter folded cylindrical >polyethylene film liner inside insulation inside a $200 3'-tall x 15'- >diameter inflatable EZ-set swimming pool. We could also make a tank with a folded EPDM liner inside a rectangle made with vertical 55 gallon water drums, with 52.8 ft^3 of heat storage volume for 2 4-drum endwalls + 37.2 ft^3 per pair of sidewall drums. If 219 = 52.8 + 37.2N, N = 4.46, so 5 pairs of side drums would do, with 52.8+37.2x5 = 239 ft^3 in 18 drums with a 10'x16' folded EPDM liner. Nick