Influence of Solar Radiation Heat Input into Room on Level of Economically-efficient Thermal Protection of Building

Abstract

Techniques for choosing an energy and economically feasible thermal protection of buildings in the climatic conditions of Moscow are discussed earlier. An important basis of these techniques is that it was possible to identify the thermal parameters on the basis of which the generalization of the basic energy and economic indicators of the building, depending on its thermal protection, was carried out. The methods were tested for buildings whose working day lasts from 9 am to 6 pm with various internal heat generation. In this case, it was believed that solar radiation is completely obscured. From consideration of the effect of heat gains on energy-efficient thermal protection, it was found that with increasing heat gains, the load on heating systems decreases regardless of the level of heat protection, and the load on the room cooling systems increases more with higher thermal protection than with low thermal protection. However, there are buildings of a number of functional purposes in which solar radiation is partially obscured or not obscured at all. These include some commercial, residential and other buildings. Accounting for heat gains from solar radiation, with variable intensity throughout the year, makes significant adjustments to the choice of the level of thermal protection. This is due to the fact that often cooling of the room is required during periods when the outside air temperature is below the maximum allowable temperature of the room. During these periods, enhanced thermal protection is an obstacle to the natural outflow of heat from the premises. Calculations showed that the higher the heat gain from solar radiation, the smaller the proportion of buildings it is energetically feasible to warm according to the basic standards stipulated in SP 50.13330.2012. And although it is not energetically feasible to carry out thermal insulation for sanitary and hygienic requirements, the conclusions about the benefits of building insulation with reduced heat transfer to the walls and coatings of a building are economically significant. It is also important that when identifying an economically feasible thermal protection of a building, it is necessary to take into account all the components of financial expenses that are affected by the thermal protection of a building. The calculations also showed that an increase in the cost of heat and electricity over time changes the thermal performance of buildings for which this or that thermal protection is economically feasible.