TY - JOUR
T1 - Reducing cooling demands in a hot dry climate
T2 - A simulation study for non-insulated passive cool roof thermal performance in residential buildings
AU - Dabaieh, Marwa
AU - Wanas, Omar
AU - Hegazy, Mohamed Amer
AU - Johansson, Erik
PY - 2015/2/15
Y1 - 2015/2/15
N2 - In hot dry climates, it is estimated that almost half the urban peak load of energy consumption is used to satisfy air-conditioning cooling demands in summer time. Since the urbanization rate in developing countries - like the case in Egypt - is rising rapidly, the pressure placed on energy resources to satisfy inhabitants' indoor comfort requirements is consequently increasing too. This paper introduces passive cool roof as a means of reducing energy cooling loads for satisfying human comfort requirements in a hot climate. A designed algorithmic hybrid matrix was used to simulate 37 roof design probabilities alternating roof shape, roof material and construction. The result of using a vault roof with high albedo coating shows a fall of 53% in discomfort hours and saves 826 kW h during the summer season compared to the base case of the conventional non insulated flat roof in a typical Cairo residential buildings. It is recommended that the selected cool roof solution be combined with natural ventilation to increase the indoor thermal comfort, and with passive heating strategies to compensate the increase in heating hours. The application is intended for low cost residential buildings in a hot dry climate.
AB - In hot dry climates, it is estimated that almost half the urban peak load of energy consumption is used to satisfy air-conditioning cooling demands in summer time. Since the urbanization rate in developing countries - like the case in Egypt - is rising rapidly, the pressure placed on energy resources to satisfy inhabitants' indoor comfort requirements is consequently increasing too. This paper introduces passive cool roof as a means of reducing energy cooling loads for satisfying human comfort requirements in a hot climate. A designed algorithmic hybrid matrix was used to simulate 37 roof design probabilities alternating roof shape, roof material and construction. The result of using a vault roof with high albedo coating shows a fall of 53% in discomfort hours and saves 826 kW h during the summer season compared to the base case of the conventional non insulated flat roof in a typical Cairo residential buildings. It is recommended that the selected cool roof solution be combined with natural ventilation to increase the indoor thermal comfort, and with passive heating strategies to compensate the increase in heating hours. The application is intended for low cost residential buildings in a hot dry climate.
KW - Cool roof
KW - Cooling demand
KW - Energy efficient roofs
KW - Energy loads
KW - Hot dry climate
KW - Passive cooling
KW - Thermal performance
UR - http://www.scopus.com/inward/record.url?scp=84921385575&partnerID=8YFLogxK
U2 - 10.1016/j.enbuild.2014.12.034
DO - 10.1016/j.enbuild.2014.12.034
M3 - Journal article
AN - SCOPUS:84921385575
SN - 0378-7788
VL - 89
SP - 142
EP - 152
JO - Energy and Buildings
JF - Energy and Buildings
ER -