Passive solar design is a technique that uses the heat of the sun to regulate a building’s temperature without using other energy sources. It is one of the ultimate forms of sustainable building design as if 100% successful, the buildings design and construction incorporates enough means to allow solar energy in, without recourse to other energy: environmentally-damaging energy, such as fossil fuels.
Ultimately, the successful use of passive solar design depends upon both the correct understanding of the sun’s movements, and the best use of materials and their sitting in order to capitalise on the solar energy.
3 Levels of Passive Solar Design
Architects refer to 3 levels or strategies of passive solar design: direct, indirect, and isolated. The direct strategy is the specific use of windows and shutters and other design features, which capture what is known as a short cycle of solar energy. Indirect passive solar design makes greater use of solar energy, with whole walls, water tanks, and earthed roofs being examples of this – the building’s structure acting as insulation, with a slow-release of heat capability. Isolated solar design refers to the capturing of solar energy and slow-releasing it through the building. Various techniques and structures such as solar stoves and chimneys have been designed and built for this purpose.
Passive Solar Design in Your Building’s Plan
Passive solar design is a wonderful technique of energy use and conservation, but it can be very tricky to get right and to be the most effective form of energy capture. It demands a creative and flexible approach.
The building’s location is clearly crucial. In many locations, too much exposure to the sun and the use of large windows and glass doors can leave houses being too hot and uncomfortable during the day. A clear appraisal of the site to be built upon needs to be undertaken, with regard given to location factors, such as other buildings or trees, which will provide shade for all or part of the day.
Then, armed with this information, the designer and those who will live in or use the building should look at the range of materials available with which to construct the building – adobe walls, for instance, absorb solar energy well and release it slowly. The walls of a building are referred to in solar design as thermal mass – the mass of material that absorbs and insulates.
The type and size of windows, as well as their location, should be very carefully considered. The shape of the building, as well as the external environment that will surround the completed project, are important factors to consider as well.
Sustainable and Creative Building Design
To fully understand this concept, and to decide how it could be adapted to work best for any new build, is to visit examples of buildings built with passive solar design as a definite design point.
Try to find buildings in the nearby location to where you intend to build, and assess the use of solar energy through the day. How long does the sun shine in the height of summer, and in the winter?
Does summer heat create humidity? If so, this has a different effect on building temperatures and conditions. Passive solar design also incorporates temperature cooling issues within a building – can a building cool day and night, or will air-conditioning have to be installed? Above all, find an experienced architect or construction engineer who has specific experience in this field. It is an important, perhaps a crucial part of planning a sustainable-built construction.
