Building heat loss to the ground is not as straightforward as heat loss to the outdoor air. As buildings become increasingly well insulated, understanding ground heat loss becomes more important. This presentation is for architects, builders, and others who want to have a better idea about how buildings interact thermally with the ground and how to calculate heat loss to the ground.
Starting with with the 2D THERM model of a basement, we'll look at the U factor that THERM calculates for the foundation assembly, and use that to calculate the design heat loss of the basement, and estimate the annual heat loss as well.
We'll do a quick reality check to vet that calculation, then present the simplified Los Alamos algorithms for calculating heat loss from basements and slab-on-grade foundations. We'll apply use these to analyze our model and compare the result with the THERM calculation. We'll discuss how to apply these algorithms to a walk-out basement condition. Finally, we'll look at how to estimate design heat loss in the case where the insulation is in the frame floor over a basement.
- Learn about relative conductivity and heat capacity of soils vs. air
- Learn about variations in soil temperature with time and depth
- See the results of a 2D THERM model of a basement, including the temperature distribution, direction of heat flow, and heat loss rates
- Learn about using the U factor calculated by THERM to estimate foundation heat loss
- Learn how to do simplified heat loss calculations for basements, slab-on-grade, and walkout basement foundations
- Learn how to estimate design heat loss through an insulated floor to a basement below