All toolsCalculatorsDuctworkDuct Heat Gain/Loss
Duct Heat Gain/Loss
Steady-state duct heat gain or loss using Q = U·A·ΔT with insulation and film coefficients.
The Ensign ToolboxDuct Heat Gain/LossSteady-state duct heat gain or loss using Q = U·A·ΔT with insulation and film coefficients.
Air Temperatures
°C
Supply or return air temperature
°C
Ceiling void / plantroom / outdoors
Labelling only — Q uses |ΔT|, magnitude is unchanged
Duct Geometry
mm
mm
m
Insulation
W/m·K
mm
0 mm = uninsulated
Film Coefficients
W/m²·K
W/m²·K
Energy Estimate (optional)
hrs/yr
Electrical = thermal / COP
%
Avg. load vs design ΔT
Enter valid temperatures, duct dimensions, and insulation data