Passive Cooling Roof Design

Engineers worked to change the concept of roof cooling from a ponding to an evaporative technique.

Passive cooling roof design.

Passive design utilises natural sources of heating and cooling such as the sun and cooling breezes. When sunlight strikes a building the building materials can reflect transmit or absorb the solar radiation. Cool roofs a cool roof is one that has been designed to reflect more sunlight and absorb less heat than a standard roof. This cooling reverses the heat flow through the roof.

Modulation is a technique used to transfer the heat via thermal mass or natural cooling dispersing it at a later time or when needed. This is a simple building integrated cooling scheme that uses nighttime radiation cooling from a metal roof to cool air in the attic space. Passive solar design refers to the use of the sun s energy for the heating and cooling of living spaces by exposure to the sun. In addition the heat produced by the sun causes air movement that can be predictable in designed spaces.

Attic air is then circulated into the living area to provide cooling. Passive cooling is free unlike air conditioning which is expensive to install and run. With just an error. This approach works either by preventing heat from entering the interior or by removing heat from the building.

Passive cooling should be part of an overall approach to passive design. Passive cooling is a building design approach that focuses on heat gain control and heat dissipation in a building in order to improve the indoor thermal comfort with low or no energy consumption. Cool roofs can be made of a highly reflective type of paint a sheet covering or highly reflective tiles or shingles. Designing the floor plan and building form to respond to local climate and site.

Researchers have developed a numerical model that was able to verify the effects on passive cooling of buildings caused by the density variation of vegetation of green roofs. Depending on your situation climate house style personal preferences etc it is most effective if you incorporate the principles of both passive cooling and passive heating. An evaporative roof cooling system is designed to reduce the temperature of a roof from 165 f to about 90 f. Natural cooling utilizes on site energy available from the natural environment combined with the architectural design of building components rather than mechanical systems to dissipate hea.

How roof cooling works. Passive cooling design principles. It is achieved by appropriately orientating your building on its site and carefully designing the building envelope roof walls windows and floors of a home. Preventive techniques are the steps you can take to keep heat from building up in the first place.

To achieve thermal comfort in cooling applications building envelopes are designed to minimise daytime heat gain maximise night time heat loss and encourage cool breeze access when available.