Also called an evaporative cooling system a roof misting system lowers surface temperatures by spraying an extremely small amount of water across the roof allowing the water to cool the roof as it evaporates.
Roof pond cooling system.
Overall 19 roof pond cooling and 4 roof pond heating systems were identified.
The main aims were to gain a detailed understanding of different roof pond configurations and their performance compare effectiveness of.
What is roof pond roof pond is a passive cooling technique based upon the increased heat capacity of cheap and widely available water.
At its lowest tech a roof misting system can be little more than a garden hose set to the mist setting and aimed across the roof.
In both processes the roof acts as a heat exchanging element which is cooled by evaporation on its surface longwave radiation to the sky 1 or both.
Exposure of the water pond to the night sky for cooling.
As water evaporates from the pond heat is consumed.
The principal constituents of a roof pond system are the container for the water the supporting structure and the thermal insulation with which the thermal coupling and decoupling of the water are achieved.
During the day water in the pond absorbs heat cooling the ceiling below.
With these elements a roof pond can contribute to thermal comfort in all seasons.
Comparing performance relative to other passive strategies showed that in many cases roof pond cooling systems are about equally effective in maintaining indoor thermal comfort.
A more refined method involves insulating the pond during the daytime to prevent solar gain.
An indirect gain design which provides both heating and cooling is the thermal pond approach which uses water encased in ultraviolet ray inhibiting plastic beds underlined with a dark color that are placed on a roof.
This review suggests that in some cases roof ponds can provide year round thermal comfort while reducing demand for.
H2o sun 3.
To demonstrate a roof pond system that uses water and sun to heat and cool without electricity.
Roof ponds provide cooling benefits through indirect evaporative cooling and or radiant cooling 19 22 23 24 25 26.
Evaporation in a pond is proportional to the air water contact area.
In general the pond is covered during day to prevent heating and open at night to be cooled.
This paper systematically reviews literature on passive heating and cooling of buildings using roof ponds.