What is it?
Passive solar design (PSD) is concerned with the use of the solar energy for heating and cooling of living quarters. It involves selection, construction, and use of appropriate PSD systems to sustain a comfortable temperature and humidity range in a home drawn from solar energy, daily or annually.
PSD reduces the need for active heating and cooling systems, as PS technologies use only solar heat, bringing down operating costs to zero. No greenhouse gases are emitted. The maintenance costs are also low since no mechanical systems are needed.
How is passive solar design incorporated into building construction?
PSD is often sought as a means to cost-effective zero energy buildings. PSDs consist of the following four main parts:
- Direct solar gain involves re-positioning windows, shutters, and exterior shading. It also involves using interior window insulation to monitor the amount of solar heat reaching the interior spaces to warm the air.
- Indirect solar gain involves capturing solar heat through a part of the building structure with appropriate thermal mass (like a water tank or a solid concrete wall behind glass). This heat is transmitted through the building via methods of conduction and convection.
- Isolated solar gain refers to capturing solar heat and then transmitting it (passively) in the building or outside by the means of a fluid such as water or air.
- Passive cooling involves the transfer or removal of unwanted heat.
What are the goals of passive solar design?
PSD goals change with the seasons. For example:
- Winter – In winter, it is important to efficiently control and retain solar heat and minimize heat loss through the structure.
- Summer – In summer, heat gain has to be monitored and at times cooling is required.
- Moderate climates in Spring / Fall – Daily weather variations with regard to sunlight, heat and humidity have to be monitored in temperate climates, according to the needs of the residents.
