Ponded Roof
Normal roof can be heated by the sun to a temperature of 100F-150F (38C to 66C). The ceilings in these roofs will radiate heat and this heat through the space below. Many houses with flat roofs are provided with some summer comfort cooling with the help of ponded roof. 2" 3" (5 cm to 8 cm) pond water covers the surface of the roof. This type of cooling is particularly well suited to one-history of the plant and trade premises. To be effective, the roof must be as large as the area.
The cooling effect comes from the evaporation of water from the roof. Naturally, ponded systems are most effective in areas of high temperature and low relative humidity, and the bright sun. By flooding, roof temperature may be lower than in the surrounding atmosphere.
Ponded roof require a means to maintain a constant water level on the roof. Drains to take away excess water from the rain. If the roof is a large breakwaters are necessary to prevent waves produced in strong wind conditions. Waves can cause a large quantity of water to be blown off the edge of the roof.
In ponded roof can reduce the required productivity by as much as 30%. However, the added weight of the roof will result in higher construction costs. In ponded roof should never be added to the existing building, if the roof structure can support the additional weight of the water...
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Air-Conditioning