In a heat loss calculation, which additional important factor is included alongside the complete building envelope?

In a heat loss calculation, incorporating atmospheric wind velocities is crucial because wind plays a significant role in the overall heat transfer from a building. Wind can enhance the rate at which heat is lost through the building envelope, particularly at junctions, windows, doors, and any other penetrations in the walls. Wind creates pressure differences across these surfaces, which can lead to increased heat loss through air infiltration.

When calculating heat loss, professionals consider how quickly the wind can remove heat from a surface and the impact of that increased loss on the overall energy efficiency of the building. This understanding is vital for accurately assessing the heating needs and improving the building's energy performance.

In contrast, while occupancy levels, soil temperature, and energy source type can influence heating requirements or indoor climate conditions, they do not directly contribute to the calculation of heat loss through the building envelope in the same manner that wind does. The focus of heat loss calculations is primarily concerned with how external factors like wind affect the building's thermal performance.