Residential buildings walls thermal reliability in the regions of ukraine
Abstract
An adequate indicator of thermal reliability level is the probable duration of thermal failure condition according to the criterion of exceeding permissible temperature difference between the indoor air and enclosure inner surface. The purpose of this work is to estimate probable durations of thermal failures of residential building walls in different regions of Ukraine and based on the results of their comparative analysis to make conclusions about the need to specify the minimum required values of heat transfer resistance.
The research was carried out according to methodology published in the author's previous works, which enables determining the probable duration of thermal failure conditions, taking into account statistical characteristics of the atmospheric air temperature in each of the administrative regions of Ukraine. As estimated, within the territory of Ukraine duration of thermal failures varies between 14...28 minutes/year. Based on the calculations results a schematic map was built, which enabled analyzing the nature of territorial variability of thermal failures duration. Within the limits of the first temperature zone of Ukraine according to DBN B.2.6-31:2021 (State Building Regulations), «Thermal insulation and energy efficiency of buildings» probable duration of the walls thermal failures operated in the north-eastern oblasts (Chernihiv, Sumy, Kharkiv, Luhansk, Poltava) is close to thermal failures duration, which is typical for the second temperature zone. The probable duration of wall thermal failures under conditions of central and western Ukraine is somewhat shorter.
For a more accurate alignment of walls’ thermal reliability indicators on the territory of Ukraine, it is advisable to allocate a separate temperature zone consisting of 14 oblasts from central and western Ukraine, defining for it the minimum permissible value of heat transfer resistance of residential and public buildings walls R0 = 3.7 m2×K/W. Reduced requirements for wall heat transfer resistance can also be established for the Autonomous Republic of Crimea and the Southern coast of Crimea, for which significantly shorter durations of thermal failures have been obtained as a result of a warmer climate.
