Thermal Mass vs Insulation — Which Is More Effective?

Choosing the Right Thermal Mass

Thermal mass refers to the ability of a material to absorb and release heat. In earth berm homes, thermal mass is often provided by concrete, brick, or stone walls. These materials can absorb heat during the day and release it at night, reducing the need for heating and cooling. A well-designed thermal mass system can reduce energy consumption by up to 30% in temperate climates.

Insulation and Thermal Mass in Harmony

While thermal mass is essential, insulation is also crucial in earth berm homes. Insulation helps to prevent heat from escaping, reducing the load on the thermal mass system. A combination of insulation and thermal mass can achieve energy efficiency gains of up to 50% in well-designed earth berm homes. A common technique is to use insulation on the exterior of the thermal mass wall, preventing heat from escaping while still allowing the thermal mass to absorb and release heat.

Designing an Effective System

When designing an earth berm home, it’s essential to consider the relationship between thermal mass and insulation. A common ratio is to use 1 part thermal mass to 3 parts insulation. This allows the thermal mass to absorb and release heat while preventing heat loss through the insulation. By working together, thermal mass and insulation can create a highly energy-efficient home that reduces heating and cooling costs.