PASSIVE COOLING IN HOT, ARID REGIONS IN DEVELOPING-COUNTRIES BY EMPLOYING DOMED ROOFS AND REDUCING THE TEMPERATURE OF INTERNAL SURFACES

Natural ventilation due to wind effects through buildings employing domed roofs was estimated by a flow network analysis. The dome was assumed to have an opening at its crown. When compared with flat roofs, the domed roofs always increase the air flow rate through the building. The increase in natural ventilation becomes significant in buildings with doors and windows all in one wall, or whenever the wind effects on the building envelope do not produce large pressure differences at the openings. The large air flow rate in the buildings with domed roofs may be utilized to store night air coolness in the structure more effectively and keep the mean radiant temperature of the interior surfaces low for thermal comfort in summer. Through a one-dimensional energy analysis the inside surface temperature of a horizontal slab was estimated for various slab materials and external and internal conditions. The inside surface temperature was compared with the case of employing a roof pond. It was found that lower temperatures can be obtained by evaporatively-cooled moist internal surfaces.