This article is the introduction and contents list for all the associated sub-articles for this test series using THERM to model concrete foundations.

THERM is available (free) from here: http://windows.lbl.gov/software/therm/therm.html
It is described as a Window Modelling tool, but it can be used for any 2D steady state thermal modelling situation.

This is the base case used:

I have tried to include all the variables specified in THERM so that you can replicate my work if you wish.

Explanation of Base Case and Model

1. This model has a large area of soil, going down 10m. The soil extends to the middle of the slab and well out from the foundations. The depth allows the simple boundary condition of a fixed temperature to be used. Ideally the temperature should match the deep ground temperature for the area in which you wish to build. At depth the temperature is constant.

2. The model includes the room air. The top of the room boundary condition is set to a constant temperature. This allows the modelling of the room air temperature gradient.

3. Felt is included on the slab to model carpet etc.

4. The only heat loss occurs to the exterior air through the short piece of wall, slab edge/brick and external soil surface, and to the deep soil boundary. The only hat source is the "thermostatic heater". The heat flow is calculated by summing the heat flow through the soil, concrete & wall boundary to the exterior air.

5. This is a simple model.

6. Insulation is added in positions p1 to p6.

This shows the details of the foundation/slab/insulation:

The insulation locations are defined here:

Example of a boundary condition setup:

Sub-Articles

Test Series 2: Table of Results:
http://neuralnetwriter.cylo42.com/node/1811

Please refer to the table of results when looking at the following sub-articles so that you understand what designs 1 to 13 are.

Test Series 2: Sample Isotherm & Temperature Plots for design 1, 3 & 7
http://neuralnetwriter.cylo42.com/node/1819

Test Series 2: Thermal Images
http://neuralnetwriter.cylo42.com/node/1812

Test Series 2: Chart Results, including Sensitivity Tests on deep soil temperature, soil moisture, film coefficient
http://neuralnetwriter.cylo42.com/node/1813

Test Series 2: The Importance of Soil Type, Moisture Content, Depth and the Dynamics of Sub-Soils
http://neuralnetwriter.cylo42.com/node/1816

Test Series 2: The Effect of Aspect Ratio & the Design Navigator Equation
http://neuralnetwriter.cylo42.com/node/1817

Test Series 2: Differences between Design Navigator & My Results
http://neuralnetwriter.cylo42.com/node/1818

Test Series 2: Conclusions
http://neuralnetwriter.cylo42.com/node/1814

Test Series 2: Discussion Thread - Please comment on my THERM modelling articles here
http://neuralnetwriter.cylo42.com/node/1815

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See also this article which has pretty diagrams of various ways to insulation foundations:

Concrete Foundation and Slab Insulation Options
http://neuralnetwriter.cylo42.com/node/1119

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