Water On The Roof For Cooling

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.

Water on the roof for cooling.

1 gallon of water consumes 8000 btu as it evaporates. These systems provide cooling by spraying the water evaporates and cools the surface. Yes you can spray your roof to help cool it down but that will only cool the shingles for a short time and be a large waste of water. An evaporating layer of water on the roof approaches a wet bulb temperature of 12 c a typical roof reaches 60 100 c mitigating the albedo effect.

Prototype for a evaporative roof for radiant cooling cherry valley ca usa reconsidering comfort. Areas where water is in short supply. One study indicates that water use is around 100 gallons per day per 1000 sqft of roof area. There should be 1 square foot of vent for every 300 square feet of floor space.

As water evaporates from the pond heat is consumed. This cools the roof which acts as a heat sink and absorbs heat from the interior of the building. The majority of time older homes do not have enough roof vents to help cool the attic in summer. 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.

A more refined method involves insulating the pond during the daytime to prevent solar gain. Yes water on the roof will help cool it. Ambient indoor temperature is approx.