Determination of the thermal time constant of the reinforced concrete building component

Abstract

As a result of changes in the boundary conditions, a heat exchange in the building envelope is not always in a steady state. Heat fluxes penetrating through the wall may be several times greater than the steady state. Thus, the building can have a much higher demand for energy and requires the use of more powerful heater than it results from the standard calculation. This article dealt with estimating the length of the transient state after changing the boundary conditions. The protective celling plate of dimensions 35 m × 1 m and a thickness of 0.5 m has been analysed. The plate, on the one hand, is cooled in air at a temperature of 8.6°C, on the other hand is inside the shelter at 20°C. A period of cooling, based on the theoretical and numerical calculations, was obtained, then the differences were discussed and the conclusions drawn. Keywords: building, building physics, heat flows in building envelopes