[Greenbuilding] Power Vent for Solar Air Heater

[Topher]

On 9/19/2013 3:33 PM, LarenCorie wrote:
> Polyethylene is transparent to IR, so only has an Rvalue of
> around 0.83

What does being transparent to IR have to do with R-value, a measurement 
of conductive heat loss?

0.83 is about the insulation value of almost anything which just blocks 
the wind (R-0.17 for outside air film (15 mph) and 0.61 for inside air 
film).  If the plastic is a film which can distort in the wind, those 
numbers are probably useless.

Thank You Kindly,

Corwyn / Topher Belknap

-- 
Topher Belknap
Green Fret Consulting
Kermit didn't know the half of it...
http://www.GreenFret.com/
topher at greenfret.com