Experimental investigation of night ventilation for cooling a kitchen in hot dry summer conditions

Abstract

Passive design strategies in buildings have been lost over the years being replaced by active systems. The energy demand for active systems in buildings have increased more and more contributing extensively to the environmental problems. Return to passive strategies in buildings design is a promising way for improving comfort and reducing energy demand. Passive strategies can be learned from traditional or old buildings in each climate zone. In this study the focus was on testing the performance of night ventilation for cooling an old building with some optimal characteristics but under extreme summer conditions in a desert climate. That is why a kitchen, which usually performs without air conditioning, was selected and monitored. Three ventilation schemes were tested: with windows closed day and night, with windows opened day and night with assisted night ventilation and with controlled windows with assisted night ventilation. Based on the results of the three ventilation schemes it is seen that night ventilation together with controlled windows allows matching indoor with outdoor average temperatures, that is, decreasing indoor average temperature about 3.6°C compared with the no ventilation scheme. It also helps to decrease indoor maximum temperatures in about 1.3°C compared with the no ventilation scheme. Although night ventilation helped lower indoor temperatures under extreme summer conditions it was not enough to achieve comfort during the usage hours even for acclimatized local people, which suggest the opportunity of application in transition periods, when temperatures are not extreme but still hot, giving the possibility of achieving the full effectiveness under hot but not extreme conditions.