A simple calculation makes it possible to determine the maximum rate of below-grade heat loss from a basement and the total heat loss over the heating season. The procedure accounts for the variation of below-grade heat loss during the year. This is a significant factor in the house heat balance. Analytical as well as experimental data are used to develop a set of factors that are then used in the calculation of below-grade heat loss. This note is a revised and extended version of an ASHRAE paper (Mitalas 1983). This revision extends the full basement calculation procedure to include slab-on-grade and shallow basement heat loss calculations.

Units: SI