Passive cooling is a way of designing a building that focuses on improving indoor heat to a comfortable level with little or no energy consumption. This is often done through non-mechanical conditioning solutions that involve preventing heat from entering the building or by removing heat from the building. To be effective, passive cooling, which is the least expensive means of cooling a building as it helps to reduce the cost of air conditioning, needs to cool the building and the people in it.
Solar heat gain prevention
The prevention of heat entering a building is known as solar heat gain prevention, which refers to the increase in temperature in a building from the sun. Almost half of all heat gain in a home is generated through windows that are unshaded. External passive cooling techniques to help keep out the heat include shading north, east or west facing windows hit by direct sunlight through the use of sun screens, awnings, roll-up shades, or creating a trellis with vines for shading. These systems can be designed specifically to cater different locations as we have done here for this dwelling in Cape Paterson along the Bass Coast.
Another solution to heat gain prevention is to install windows with passive and solar control low-e coatings. This minimizes the amount of ultraviolet and infrared light that passes through glass. Moveable reflectors reduce heat gain in the summer. A curved reflector acts as a shade and reflects sunlight to prevent heat from reaching the skylight and heating a space. However, it does so while still allowing daylight to enter
Natural cooling methods
The removal of interior heat is known as natural cooling. One way to maximize heat loss is by creating a thermal chimney. This is achieved in a home by opening the lowest windows on the side of the home where the breeze is coming from and leaving interior doors and upstairs windows on the opposite side of the house open. This works much like a chimney in that the warm interior air is draw upwards and out the upper windows.