Full Description

The energy performance of the above-grade portion of buildings is generally well understood. Hourly prediction of heat transfer from walls exposed to ambient, air has helped improve the thermal efficiency of building envelopes. Unfortunately, the attention to foundation heat transfer has lagged behind other building components. Today, the need for a quantitative understanding of foundation heat transfer is greater than ever before to accurately predict and thus improve the overall energy performance of a building. It is estimated that a basement kept uninsulated may contribute up to 60 percent of the heat loss in a tightly-sealed home that is well insulated above-grade.

The present study is undertaken to satisfy the need for an accurate yet flexible simulation method to predict heat transfer from basements, slabs, and crawl spaces suitable for use in major hourly building energy simulation programs.

The four broad objectives of this work are to:

(i) Develop semi-analytical solutions that can handle all of the common insulation configurations for basements, slabs, and crawl spaces. The solutions will be based on the well-documented Interzone Temperature Profile Estimation (ITPE) technique. Fortran-77 codes will be produced in neutral model format suitable for use with major hourly building energy simulation programs.
(ii) Validate the results of the ITPE solutions against, both empirical data and detailed three-dimensional numerical models.
(iii) Develop a numerical model to predict soil surface temperature variation. This model will consider effects of ground cover, soil properties, solar radiation, and convection heat transfer. The model will be validated against empirical data collected by the Joint Center for Energy Management (JCEM).
(iv) Generate response factors for foundation walls and floors for use with major hourly simulation programs such as DOE-2 and BLAST. Implementation of these response factors into DOE-2 will be demonstrated.