What Does Thermal Accumulation of a Wall Mean?

The ability to store (accumulate) heat and release it when the room begins to cool down.

Thermal accumulation of a wall refers to its ability to store heat. This depends mainly on the weight of the partition and the material from which it is made. That is why brick buildings and structures with high load-bearing capacity have a much higher ability to accumulate heat than wooden and lightweight constructions (wooden or steel).

Here is an example demonstrating the importance of thermal accumulation:

• In a heavyweight building with very good thermal insulation (C/B), the indoor temperature should not drop by more than 1°C, even when the outside temperature is -20°C.
• In a heavyweight building with poor thermal insulation (C/S), the indoor temperature may drop by 3°C, requiring more energy to restore the recommended 20°C room temperature.

The thermal stability of a building depends on the accumulation of heat in internal walls, partitions, and construction layers, meaning how long the indoor temperature remains stable despite external weather changes (e.g., severe frost or strong winds) or the heating being turned off.

For a partition to accumulate heat and release it inside, it must be insulated from the outside.

Why Is Thermal Stability Important?

• In permanently inhabited buildings, high thermal stability is required because it helps stabilize the indoor temperature.
• However, this is not beneficial for buildings that are not regularly used and are only heated on weekends, such as summer cottages, agricultural buildings, or tool sheds.