Evaluation of the 24-hour thermal conditions of a dwelling room in the warm period of the year in Moscow

Introduction. In modern design practice, it is customary to calculate the cooling capacity of an air-conditioning system as the sum of the maximum heat inputs into the room from the individual sources. The indoor air temperature in such calculations is assumed to be equal to the required temperature according to the hygienic norms. In this case, the calculation itself is performed with consideration of stationary heat transfer.Materials and methods. The 24-hour thermal conditions of a dwelling room in Moscow with a window facing east were calculated. The calculation results were compared for steady-state and non-steady-state thermal conditions. Temperature maintenance in the room was achieved by night ventilation with outside air and daytime cooling with air from the Split-system, as well as by the cooling system with supply air. The chilled air temperature was assumed to be 20 and 22 °C.Results. The changes during the day in indoor air temperature in a room oriented to the east were determined. It was found out that at a maximum daily outdoor air temperature of 33 °C, maintaining indoor air temperature not higher than 24 °C is possible only if the room is cooled with supply air of 22 °C and below 24 hours a day. It is also possible to cool the room starting at 5:45 a.m. with supply air cooled to 20 °C. In this case, the solar heat transmittance coefficient of the window should be no higher than 0.5.Conclusions. Since in recent years there are higher outdoor air temperatures than before, it is advisable to increase the design outdoor air temperature during the warm period of the year.

outdoor air temperature, heat inputs from solar radiation, calculation, indoor air temperature, night ventilation, cooling with supply air in daytime and 24 hours a day