Indoor temperature increase at reduced cooling power in light and heavy buildings - measurements in 9 buildings and Monte Carlo simulations of parameters

Saving peak powers in the heating systems have been in focus for some years now. Sweden has more and more cooling systems with an increase in cooling also in residential buildings. The cooling power is much more expensive than the heating power and the cost of cooling is largely driven by installed power. Therefore, there is a relative advantage of reducing the cooling power instead of heating power, and at the same time the traditional users are accepting over temperatures indoors more than if the temperature becomes too low. Buildings facing renovation as well as new construction will reduce the use of heating, while more cooling power will be needed to cover the lack and future climate scenarios with warmer outdoor temperatures. In this study, the indoor temperature of 9 large buildings located in South Sweden were measured during cooling power drops on a summer day of the cooling systems to give an answer to the feasibility of controlling the cooling peak power of the grid and supply system by utilizing the thermal mass of the buildings without making a too big compromise of the indoor temperatures. To support the measurements with parametric results, Monte Carlo simulations were also made to verify the measurements and to give advices on the probability of certain temperature increases for specific situations. Heavier frame and interior material inside increase the possibility of shutting down or reducing cooling power, as well as heating power, but also the thermal inertia of the cooling system.