Loss in Basements

The amount of heat lost from a basement will depend upon a num­ber of different variables. An important consideration, for example, is ground temperature, which will function as the outdoor design temperature in the heat loss transmission formula. The ground temperature will vary with geographical location (Table 4-2).

The usual method for calculating heat loss transmission through basement walls is to view them as being divided into two sections (Figure 4-3). The upper section extends from the frost line to the basement ceiling and includes those portions of the wall exposed to outdoor air temperatures. The heat loss for this section of the base­ment wall is calculated in the same way that other surfaces exposed to the outside air are calculated. The section of the wall extending

Sizing Residential Heating and Air Conditioning Systems 85 Table 4-2 Ground Temperatures Below the Frost Line

From the frost line to the basement floor and the floor itself can be calculated on the basis of the ground temperature. The ground tem­perature is substituted for the outside design temperature when cal­culating heat loss.

Posted in Audel HVAC Fundamentals Volume 1 Heating Systems, Furnaces, and Boilers