The basic natural processes used in passive solar architecture are the thermal energy flows associated with radiation, conduction, and natural convection. When sunlight shines on a building, the building materials can reflect, transmit, or absorb the solar radiation. Additionally, the heat produced by the sun causes air movement that can be predicted. These basic responses to solar heat lead to design elements, material choices and placements that can provide heating and cooling effects in a home.
This form of architecture dates back to the start of human settlement and examples can be seen throughout the countryside and in older areas of cities.
Passive solar techniques enhance comfort because they prevent the solar gain. Internal temperatures are therefore much more uniform particularly if with natural ventilation is also used.
The advantages of passive solar architecture are:
- reduction in solar gain in summer so decreasing the need for cooling
- increase in solar gain in winter so decreasing the need for heating
- as only passive elements are used no energy is consumed and no pollution created
- cost effectiveness as passive elements have similar life to the building itself
- enhances appearance of buildings as traditional architectural elements used
- reduced use of fossil fuels
- reduced rate of climate change
- reduced noise levels from air conditioning systems
The disadvantages of passive solar architecture are:
- they are best undertaken when a building is being designed
- the building may not be suitably orientated to enhance solar gain in winter
- in some protected areas it may not be possible to change the external appearance of buildings
- for some forms of building construction it may be difficult to attach passive solar elements