Window U-Factor Heat Loss Calculator
Calculate heat loss through a window from U-factor, area, and ΔT.
Hourly Heat Loss
240.0 BTU/hr
Daily Heat Loss
5,760 BTU/day
Annual (heating season)
1,037 kBTU/yr
Window Area
20.0 ft²
U-Factor
0.300 BTU/hr·ft²·°F
ΔT
40.0°F