Passive design helps you maintain the interior temperature of your home with little mechanical heating and cooling.
You can use passive design ideas when you are planning a new home or for your existing home.
Passive design ideas include:
- insulating the ceiling, walls and floor
- sealing draughts around doors and windows
- allowing winter sun to warm the house
- stopping summer sun from entering the house
- using natural airflow to help with cross-ventilation.
The Your Home Technical Manual has information about Australia’s climate zones and passive design options. These include effective shading, passive solar heating, passive cooling, thermal mass and window glazing.
Passive Solar Design
Courtesy: Department of Energy
There are four key components to successful passive solar design:
1. Windows (“apertures”): These are the collectors through which the sunlight enters the home. In a passive solar house plan, the majority of the home’s windows are on the south-facing side to maximize wintertime heating. In order to minimize undesirable solar gain in the summer, passive solar house plans may have no windows/glass on the east or west-facing sides of the house.
2. Materials that retain or store the sun’s heat, also called “thermal mass.” In some designs, a separate absorber, or the surface of the thermal mass, is also present. Often, though, the thermal mass is a concrete and/or tile floor.
3. Heat distribution: This is how the solar heat circulates after entering the windows to different areas of the house. Fans, ducts, and blowers can sometimes be used to assist this process.
4. Heating control: The primary means is to use deliberately designed roof overhangs. Blinds, electronic sensing devices, vents/dampers, and awnings can also be used to control the amount of solar heating in the home.
Passive design is the very foundation of any green building. The approach uses the sun’s energy to provide comfort and
light, and to replace services otherwise provided by mechanical means. It includes features such as solar heating and cooling, thermal mass, natural ventilation and daylight.
Need for an Active Occupant
A passive building requires an active occupant. Active occupants are in tune with their surroundings. They tolerate a wider range of “comfortable” conditions, knowing that a constant 22.5°C is unrealistic in a low-energy building.
They are willing and able to modify their building to maintain their necessary comfort: they’ll turn on a ceiling fan, close a window, open a blind and switch lights on and off (just as they do at home). The know what needs to be done, and they do it.
- Design Considerations: Keep it simple.
- Use modelling
- Key features and optional extras: Include at least three key features: Ceiling fans, Shading features (including blinds), insulation and good quality glazing. When push comes to shove, be willing to give up: Sophisticated new technology, non-essential automation and very-high-performance materials
- Training building users how to use
- Communicate with occupants and agree the design parameters