Research of the energy efficiency of a combined air and water heating of a public building

Abstract

Combined air and water heating schemes have been actively used recently for heating public and residential premises. They have certain advantages in countries with a warm climate, whereas in a temperate climate, their use may be unfeasible. The most effective regulation of the heating system in the building can be expected, if all the technology specifics are taken into account, in terms of both the purpose of the room and the methods of regulation. A system focused only on weather-based regulation falls short of meeting to energy-efficient control classes: a heat carrier with the same temperature is distributed among rooms with different requirements for temperature and humidity characteristics. The issues of ensuring the energy efficiency of the combined air and water heating system in public buildings for the temperate continental climate of Russia — the academic building (AB) and laboratory building (LB) of the Kazan State Energy University (KSEU) have been considered. Heating devices of the KSEU heating system have manual control valves installed in the premises, or radiator valves with thermostatic heads, but without room controllers, which does not meet the energy-efficient control classes. An experimental survey of the functioning of the heating system of the KSEU buildings during the 2019 – 2020 and 2020 – 2021 heating seasons was conducted. The optical pyrometry method was used to measure the temperature of the surfaces of windows, walls and elements of the heating system, as well as the temperature and humidity of the air in lecture rooms and corridors of the AB and LB of the KSEU. The parameters of heating devices and indoor air in rooms of various purposes were found compliant with the current sanitary and hygienic requirements. At the same time, the need to switch to a higher class of regulation has been revealed, since, under the current situation, the parameters of the indoor air depend on the outdoor temperature: in the abnormally warm winter of 2020, the indoor air temperature was at the edge of the maximum permissible value, while in the normal climate of winter of 2021, it was at the edge of the minimum permissible value.