Compare heat flow through a wall, roof or window area.
Use net area; exclude openings calculated separately.
Use the whole assembly value, including repeating bridges.
Indoor temperature minus outdoor temperature.
Transmission heat loss
600W
Equivalent heat rate
0.60kW
Steady transmission through one assembly. Excludes air leakage, ventilation, other surfaces and heating-system efficiency. This is not a boiler-size or annual-savings calculation.