CH-85-19-2 -- A Comparison of Seven Basement Heat Loss Calculation Methods Suitable for Variable-Base Degree-Day Calculations PDF

Seven heat loss calculation methods are applied to a prototypical basement in five U.S. cities to compare predicted annual energy usage. Each method and its limitations are briefly described. Heat losses are calculated for R-1.5, R-6.5, and R-16.5 walls. The sensitivity of each method to basement depth, insulation R-value, and soil conductivity is also investigated.

It is found that predicted annual energy loss varies by more than a factor of two in spite of claims of instrumented field verification for most methods. When wall loss is considered separately, the agreement is much better than when floor losses are included. The parametric studies point to differences in the computer models used to generate the predictions. It is concluded that there is presently no standard against which to measure the accuracy of any basement heat loss method.

A discussion of the influence of soil and climatic properties emphasizes the importance of accurate data for soil conductivity, moisture content, and ground temperature.