01887nas a2200169 4500008004100000050001500041245008600056210006900142260002700211520128600238100002501524700002401549700001901573700002201592700002201614856008101636 2006 eng d aLBNL-6124900aEvaluating Fenestration Products for Zero-Energy Buildings: Issues for Discussion0 aEvaluating Fenestration Products for ZeroEnergy Buildings Issues aCambridge, MAc08/20063 a

Computer modeling to determine fenestration product energy properties (U-factor, SHGC, VT) has emerged as the most cost-effective and accurate means to quantify them. Fenestration product simulation tools have been effective in increasing the use of low-e coatings and gas fills in insulating glass and in the widespread use of insulating frame designs and materials. However, for more efficient fenestration products (low heat loss products, dynamic products, products with non-specular optical characteristics, light redirecting products) to achieve widespread use, fenestration modeling software needs to be improved.

This paper addresses the following questions:

1) Are the current properties (U, SHGC, VT) calculated sufficient to compare and distinguish between windows suitable for Zero Energy Buildings and conventional window products? If not, what data on the thermal and optical performance, on comfort, and on peak demand of windows is needed.

2) Are the algorithms in the tools sufficient to model the thermal and optical processes? Are specific heat transfer and optical effects not accounted for? Is the existing level of accuracy enough to distinguish between products designed for Zero Energy Buildings? Is the current input data adequate?

1 aArasteh, Dariush, K.1 aCurcija, Dragan, C.1 aHuang, Yu, Joe1 aHuizenga, Charlie1 aKohler, Christian uhttps://buildings.lbl.gov/publications/evaluating-fenestration-products-zero