Dynamic effects of bang-bang control on the thermal performance of walls of various constructions

The problem of energy consumption during heating and cooling with bang-bang control based upon room air temperature is studied. An analytical model is solved using the Laplace Transform technique, yielding an exact solution to the system. TMY weather data are used from four locations during the months of August and January to assess climatological effects. Approximate models are developed to explain the time lags observed during free response, and the observed chattering rate under bang-bang control. Results indicate the presence of a thermal mass effect due to the nonlinear interaction between the thermal wave penetrating the wall and the control function, with a greater effect for walls of massive construction, and in moderate weather conditions.