Glazing Material Comparison -- Poly Selection----Why Poly or Glass? -- -- Quote & Order

Data presented in honest, straight forward manner. Some materials best suited to certain applications. Indication made of appropriateness of each glazing material.

Light Transmission for clear & are those published by the manufacturer.

R-Values stated for real world conditions, Winter Nighttime: 15 mph outside wind, 0º outside temp., 70º inside temp., no sun. High R-Value = low heat loss.

Condensation on inner layer of glazing decreases as the R-Values increases.

 

Conclusions: Selection of glazing results in a pay now or pay later situation. Polyethylene materials require frequent replacement, resulting in material & labor costs. Low R-Value & light transmission of 2-wall polyethylene sheet results in higher heating & lighting costs. Glass is expensive, easy to break & eventually requires replacement, seals will fail..

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Caution: A few companies sell 3.5 & 5mm 2-wall polyethylene and advertise R-values of 2.5. This is a gross overstatement. With 25 years dealing with glazings I am confident the previous statement is correct. Look for contacts at organizations below who will agree R-values of 2.5 can not be achieved with 3.5 or 5mm 2-wall polyethylene. Dept. of Energy Energy Star Program, Lawrence Berkeley Labs Window & Daylighting Program & National Fenestration Rating Council. Polycarbonate R-values are backed up by test data and are stated in polycarbonate manufacturer literature.

 

--Polycarbonate is increasingly a chosen glazing material.

--High Light Transmission, High R-Value, Moderate Cost and Easy Installation.

 

--Quoting & Ordering --------Reload Sundance Supply Site