Thermal accumulation of the building is the ability of a building to store thermal energy in its structural and finishing elements and to release it gradually over time. This phenomenon is due to the physical properties of the materials used, in particular their mass, density, specific heat and thermal conductivity. The arrangement of the layers of the partitions and the way in which they are connected is also important.
Thermal accumulation plays an important role in shaping the temperature stability of interiors. Buildings with high accumulation capacity react more slowly to changes in external temperature, limiting rapid cooling in winter and overheating in summer. This directly affects the thermal comfort of the occupants and the energy requirements for heating and cooling.
In energy design, thermal accumulation is one of the factors to be taken into account when assessing the energy efficiency of a building. It is also important for the behaviour of the building under varying heat loads.
