Reducing heat gain in buildings by artificially lowering the outside air temperature through evaporative cooling

Abstract

Introduction. Systems for microclimate regulation in buildings consume a large amount of natural energy resources. Statistics show that 40 % of energy is used for heating, ventilation and air conditioning. This problem is directly related to the heating and cooling load of the building, i.e. it depends on the thermal engineering characteristics of building envelopes and the thermal protection of the building. Materials and methods. To reduce the consumption of energy resources, the most common method is the thermal insulation of enclosing structures, increasing the thermal resistance of enclosing structures, which is a complicated thermal engineering problem. An alternative new method of reducing heat gain into buildings through evaporative cooling of outside air which leads to reduction of cooling load of building and subsequently influences the reduction of greenhouse gas emissions is considered. For this purpose, a spray irrigation system is installed on the southern wall of the building to lower the conditional boundary layer temperature which is formed as a result of solar radiation. Results. The suggested method passively reduces the boundary layer temperature, which tends to the temperature of the wet-bulb thermometer, as a result, the heat influx into the building is reduced, which leads to a lower cooling load and increases the energy efficiency of the system. Conclusions. Green architecture and zero-energy building design are relevant and important at the present time. World statistics show that 14 % of all potable water is used in buildings, in order to use potable water economically the proposed system installs a rainwater accumulation tank for outdoor irrigation. A comparative analysis showed that by cooling evaporation and artificially lowering the outside air temperature, the cooling load of the building is reduced by 20 %, which results in a reduction of greenhouse gas emissions.