Application of Combined Passive Cooling and Passive Heating Techniques to Achieve Thermal Comfort in a Hot Dry Climate

Abstract

The hot dry regions in Mexico occupy more than seventy-five percentage of total land surface with severe climate conditions for both cooling and heating seasons. The buildings located in these regions present large energy consumption patterns due to their high dependence on air conditioning (AC) for providing comfort to the occupants, which in turns provokes the emission of huge amounts of greenhouse gasses (GHG) to the atmosphere, affecting the environment at regional al global levels. For those people who cannot afford AC in their buildings, the situation is even worse, as it severely affects their health conditions. This research work deals with the investigation of several passive cooling and heating techniques in experimental modules aimed at achieving hygrothermal conditions for building occupants. These cooling techniques involved the four environmental heat sinks and included: Ground cooling, solar control, night ventilation, direct evaporative cooling, night sky infrared radiation and thermal insulation. During the typical underheating season, direct and indirect heating techniques along with infiltration control and thermal insulation were implemented and examined. These systems were built and implemented in experimental cells during the prevailing overheating and underheating periods and the results showed that the combined effect of the strategies provided more promising synergy results than the single influence of any of them. During the underheating period, the indoor minimum temperature was 15° C, and the maximum temperature during the overheating season registered 29° C. Therefore, it is suggested to implement the combined action of the passive cooling and heating techniques in buildings located in representative hot dry regions of Mexico, to improve hygrothermal comfort and to reduce the energy consumption for AC and this would eventually reduce also the emission of pollutants to the atmosphere.