Determine the window’s U Value

Q: How do you calculate annual the heat loss of a window?

A: QT-srfc = Areawin U-Valuewin ft Gt

( ft2 ) ( Btu / hr-ft2-F ) ( kFhr / yr)

In order to calculate the transmission heat loss for each surface of a building, we need to: 1. Determine the window area 2. Determine the window’s U-Value 3. Determine the temperature correction factor 4. Determine the annual difference in temperature between inside and outside

bldgtyp | NYPH