Numerical modelling of thermal comfort conditions in an indoor space with solar radiation sources

Abstract

In this paper, a three-dimensional case of heat transfer and air flow is presented for indoor space cooling with a wall-mounted A/C unit during the summer in Rijeka, Croatia. Numerical modelling is used to analyse the effect of different air flow angles of the A/C unit on the temperature and air velocity distribution under standard conditions with and without a direct solar radiation source. As parameters of thermal comfort conditions, the airflow velocities, indoor temperatures with its gradients, and the mean radiant temperature are analysed. Physical processes are modelled using the FLUENT computational fluid dynamics software. Calculations are carried out for an empty room without internal heat sources. When direct solar radiation through the window for an extreme case of summer solstice is included in the calculation, considerable deviations from thermal comfort conditions are observed, yielding the conclusion that solar radiation must be included in numerical simulations to properly predict heat balance and thermal comfort parameters in enclosed spaces.