Roof Pond Cooling System

Overall 19 roof pond cooling and 4 roof pond heating systems were identified.

Roof pond cooling system.

To demonstrate a roof pond system that uses water and sun to heat and cool without electricity. This cools the roof which acts as a heat sink and absorbs heat from the interior of the building. This review suggests that in some cases roof ponds can provide year round thermal comfort while reducing demand for. Exposure of the water pond to the night sky for cooling.

During the day water in the pond absorbs heat cooling the ceiling below. In general the pond is covered during day to prevent heating and open at night to be cooled. 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.

This paper systematically reviews literature on passive heating and cooling of buildings using roof ponds. Roof ponds with wet gunny bags shaded roof ponds ventilated roof ponds and roof ponds with movable insulation proved to be more effective relative to other variants of roof pond cooling systems. Roof ponds provide cooling benefits through indirect evaporative cooling and or radiant cooling 19 22 23 24 25 26. In the simplest form this involves placing a pond on the building 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. 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. With these elements a roof pond can contribute to thermal comfort in all seasons. 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.

Evaporation in a pond is proportional to the air water contact area. A more refined method involves insulating the pond during the daytime to prevent solar gain. 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. H2o sun 3.