Is the ISF a concrete monolith or high moisture content sand buried under the floor system?
A. Micro encapsulated PCM’s (phase change materials) will soon be the wave of the future. This is because wax and salt can store about ten times the thermal energy of water. The size and storage medium desired for the thermal battery is a variable based on: what the heating requirements are, location of the structure, and available local materials. In this respect, a myriad of materials can be employed for the thermal battery, including PCM’s, dry or high moisture content sand, a poured monolith, or other viable thermal storage mediums. The size of the thermal battery will vary depending on the needs of the building and location. The storage battery itself doesn’t necessarily have to be in the Earth, but an exterior mound or earthberm can also function as the thermal battery. The difference between the energy signatures of geodesic construction compared to standard construction also plays a part. On average, a traditionally built home will consume roughly 80,000 BTU’s of energy a day.
