Passive Cooling
HYBRID COOLING SYSTEMS
- Hybrid cooling systems are systems that combines all aspects of passive and mechanical cooling to achieve maximun results for the whole home. They are most often used in areas where there are extreme climate conditions,
or poor design must be overcome.
- Refrigerated systems are expensive not only to install but to maintain because they consume so much electricity.
- Efficient air-conditioning requires more than simply installing an air-conditioner. Shading, ventilation and passive heating or cooling all play a part in the efficiency of the system
- Design your home to take advantage of passive heating and cooling right from the beginning. Adding a system to try and fix discomfort resulting from bad design is not always effective or efficient.
ENVELOPE DESIGN
- Building Envelope refers to the exterior walls and structure of your home.
- Passive design should include passive heating provision for winter in all climates except hot humid (tropical). The degree of winter heating can be adjusted for climate with appropriate passive solar shading.
GENERAL DESIGN PRINCIPLES
- Design to reduce heat gain during the day.
- Design to allow lower night time temperatures and air movement to cool the building and its occupants.
- The main elements of design for passive cooling are:
- Orientation for exposure to cooling breezes.
- Create unobstructed paths through the building to increase ventilation.
- Use fans when ventilation is not available.
- Plan room use to take advantage of activities
- Floor plan zoning to maximise comfort for daytime activities and sleeping comfort.
- Appropriate windows and glazing to minimise unwanted heat gains and maximise ventilation.
- Effective shading (including planting).
- Adequate levels of appropriate insulation.
- High thermal mass construction in regions with significant diurnal ranges.
- Low thermal mass construction in regions with low diurnal range.
- Use of light coloured roofs and walls to reflect more solar radiation and reduce heat gain.