Impacts of Glazing on Passive Cooling your home
Passive heating comes from only one source the sun or solar radiation. Passive cooling comes from many sources; air movement, outside breeze, evaporation, earth coupling and reflection radiation.
The Gold Coast and Brisbane are considered a warm or temperate climate which then requires both the heating and cooling design requirements for your residential or business dwellings.
For example at my home in Burleigh Heads, we do not have air conditioning, from November to May we rely on the sea breeze or fans, to cool the house. This is passive cooling using free or low energy input solutions to cool your home.
The glazing design within a building will significantly impact the heating and cooling requirements. Apparently close to 40% of a buildings heat energy can be lost via the glass. More importantly, it is also reported that up to 85% of heat in a building will be gained via the glass. When renovating or building a new dwelling, window design will have a direct impact on the dwellings thermal performance (your comfort) and ongoing energy costs. Poorly designed glazing works as a passive heat load, not something you want.
In SE Queensland, it is important then to get the passive cooling of your building right and minimise the passive heat load.
Using cross ventilation, shade, films or tinting on window glazing can all help to prevent solar radiation or passive heat load. Additional structural passive cooling options may include lighter colours to reflect heat, thicker insulation and frame styles.
There is a huge range of glass windows styles and these will affect the impact on passive cooling.
For example window opening angles impact on how much cross ventilation can be achieved. The best windows for cross ventilation are louvres, hinged or pivoting windows as they open to at least 90°. Less effective window types for passive cooling are awning, hopper or casement windows, as these have short winders, providing smaller openings and less cross ventilation.
Consider installing new louvre gallery’s to allow breezes to pass through the building. Use of obscured glass will also help to maintain privacy and security. For passive cooling consider louvre placement, above doors or in internal walls to improve cross ventilation.
Glazing has the ability to make your home more liveable for more information – http://www.yourhome.gov.au/introduction/welcome-your-home.
