What are Thermal Conductivity Values of Common Materials?

Thermal Conductivity of Common Building Materials

Thermal conductivity is crucial in earth berm homes, as it affects heat transfer between the interior and exterior. Insulating materials generally have low thermal conductivity values, reducing heat transfer. For instance, fiberglass batts have a thermal conductivity of 0.02 W/mK, while spray foam insulation can range from 0.02-0.03 W/mK. In contrast, materials like concrete (1.7 W/mK) and brick (0.8 W/mK) have higher thermal conductivity values.

Importance of Thermal Mass in Earth Berm Homes

Thermal mass materials like concrete, brick, and rammed earth have high thermal conductivity values, which allows them to absorb and release heat. This helps regulate interior temperatures in earth berm homes, reducing the need for mechanical heating and cooling systems. In earth berm construction, thermal mass walls can be designed to absorb heat from the sun during the day and release it at night, creating a natural cooling effect.

Insulation and Barrier Techniques

To minimize heat transfer, earth berm homes often employ insulation and barrier techniques. Insulation materials like fiberglass and spray foam are placed in wall cavities to reduce heat transfer. Air-tight barriers like plastic sheeting or spray foam can be applied to prevent air leaks and thermal bridging. Additionally, earth berm homes may incorporate thermal breaks like foam board or insulation blankets to reduce heat transfer between the exterior and interior.