Article 30385 of alt.solar.thermal: Path: news.misty.com!not-for-mail From: nicksanspam@ece.villanova.edu Newsgroups: alt.solar.thermal Subject: Re: R-values of reflective insulation materials Date: 30 Apr 2008 10:12:12 -0400 Organization: Villanova University Lines: 28 Message-ID: References: <48177a6c@clear.net.nz> <48185e51@clear.net.nz> NNTP-Posting-Host: acadia.ece.villanova.edu X-Trace: max.inside.misty.com 1209561115 10973 153.104.44.130 (30 Apr 2008 13:11:55 GMT) X-Complaints-To: abuse@misty.com NNTP-Posting-Date: Wed, 30 Apr 2008 13:11:55 +0000 (UTC) Xref: news.misty.com alt.solar.thermal:30385 Solar Mike wrote: >Trickle panels are: >3m high x 1m width galv iron sheets, matt black powder coated on the sun >side, water channels made by vertically running silicon beading spaced every >5cm down the metal sheet, laying 75u clear mylar on top of the silicon, >lightly pressing before it sets to form a vapour shield. The water runs >between the metal and the mylar. Each panel then sits in a wood frame with >an overall cover of 1mm flat clear thick polycarbonate with uv protection. Gary and I thought about a polyethylene inner cover for a pond-type collector/store, spaced away from a hot stagnated horizontal EPDM draindown cover/collector over polyiso board surface... >Time will tell how long the mylar will last. The poly glazing will block the >uv entering the box and hopefully stop the plastic header/bottom water pipes >from falling to bits.. > >> Multiple relfective airspaces require iteration to determine intermediate >> surface temps, as described in ASTM STP 1116. Adding individual airspace >> resistances does not work. I don't think the iteration is difficult. Assume initial surface temps, then adjust one, based on the rest, then adjust another, assuming the rest are fixed, and so on, until they don't change much. Nick