Formation of local asymmetry of the resulting temperature at the boundary of the serviced area of the premises

Moscow State University of Civil Engineering, Yaroslavskoe shosse, 26, 129337 Moscow, Russia

¹ Corresponding author: lanserser@mail.ru

Abstract

The required resistance to heat transfer of windows has been normalized for a long time depending on the functional purpose of the building and the difference in the temperature of the indoor air and the temperature of the coldest five-day period. For residential and public buildings, they were in the range of 0.18 – 0.61 m^²°C/W. In 1993, with the introduction of requirements for this indicator based on energy savings (according to the number of the degree-days of the heating period), they were increased for windows to the limits of 0.3 – 0.8 m^²°C/W. From 15.06.2019, the Amendment №1 to SP 50.13330.2012 "Thermal protection of buildings" came into force and increased the required heat transfer resistances of residential and public buildings to the range of 0.49 –0.8 m^²°C/W. Attention is drawn to the inadequacy of GOST 30494–2011 requirements as for measuring the local asymmetry of the resulting temperature in the center of the room. Such an erroneous requirement is that the radiation temperature, which is an integral part of the resulting one, depends on the measurement place. The radiation temperature in accordance with the V.N. Bogoslovsky's second comfort condition should be checked at the border of the serviced zone. Calculations of the local asymmetry of the radiation temperature, which has been measured at a distance of 0.5 m from the center of the window, showed that the optimal requirements to the center of the room are not met in none of the 19 cities of the Russian Federation for which the calculations were performed. Therefore, when forming the required resistance to the window heat transfer, it is proposed to take into account not only the number of the degree-days of the heating period, but also the calculated outdoor air temperature for the cold period of the year.