What is the heat loss equation?

The formula for heat loss is Q=U*A*?T. Q represents heat loss, and it is found by multiplying the U value of the materials in any given area, or A, multiplied by the change, ?, in temperature, T.

The U value is the measure of heat loss in a building element. It is the overall heat transfer coefficient, which measures how well the building element transfers heat. Higher U values indicate worse thermal performance. High levels of insulation usually result in a low U value. The difference in temperature is calculated between inside and outside temperatures of the two surfaces, not the two air temperatures.