Does anyone know if the VLT factor inserted into the day lighting prescriptive path spreadsheet is for the glazing only, or is it supposed to factor in the mullions/screens? If we should factor in the mullions/screens has anyone found a formula of how to incorporate all the components? We are wondering because the window manufacturer (Anderson) has provided us with a low VLT (.39) that is for an entire assembly and factors in mullions, screens, etc. We need to have a higher VLT to comply with the prescriptive path. If we use a glazing VLT only for the type of glazing we want to use, then the spreadsheet formulas work out and show compliance. No sure what info LEED is looking for in the case of a prescriptive path.

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TODD REED

Energy Program Specialist

PA DMVA

LEEDuser Expert

626 thumbs up

Mon, 04/09/2012 - 19:12

You need to use the center of glass VLT which you should be able to get from the glass manufacturer. Your window area in the prescriptive method should not include the mullion area, only the actual area of glass.

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FAQs about IEQc8.1 :

Calculating VLT- Glazing Only or Full Assembly

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