Temperature plays a big part in our comfort, and while we can’t control the temperature outdoors, there is some expectation that indoor environments be manipulated to maintain a comfortable temperature at all times.  

In the past few decades, we have relied heavily on air conditioning to make hot Australian summers more bearable, but with energy prices skyrocketing and green awareness growing, we’re starting to look for techniques and technologies that keep buildings cool without using power, otherwise known as passive cooling.

Passive cooling is the least expensive means of cooling a home and has the lowest environmental impact, working to minimise heat gain from the external environment rather than just ‘covering it up’ with cold air-con.  Not only are passive cooling solutions environmentally friendly and cost-effective in the long run, many are also attractive additions to an existing design.

According to the South Carolina Energy Office, carefully positioned trees can save up to 25% of household's energy consumption.  However, this solution isn’t always practical for densely populated urban areas where space is at a premium.  Living green walls and roof systems, such as these from Elmich Australia, can substantially improve a building’s insulation qualities and reduce the amount of heat transfer whilst also improving air quality and on-site water retention.

Increasing the amount of shade on a building’s facade is an obvious way to promote cooling, with as much as half of the heat gain in a building coming from unshaded windows.  Whilst an office or room may be artificially cooled to 21 degrees through the use of air-conditioning, areas near windows can reach upwards of 37 degrees or more, with the conflicting temperatures causing discomfort and bodily confusion.  

Installing shades or awnings over these windows reduces the amount of heat penetrating the building.  UV resistant fabrics like those used by Sunbrella also protect those inside from the harmful effects of sunlight, offering 98% protection from UV rays.

It is well known that white-coloured objects reflect heat and research released by the University of Melbourne has confirmed the cost- and heat-saving benefits of white roofs and exteriors.  But if white walls aren’t in line with your vision, heat reflective paints and coatings can help lower the internal temperatures of buildings by up to 20 degrees.  

Solar Cool, manufacturer of Insultec heat reflective coatings, applied the product to a large industrial building with a metal roof in Brisbane, that was displaying a temperature of 55.8°C on the underside of the roofing. After the roof was coated with the heat reflective paint the temperature was measured at 38°C, significantly dropping the internal temperature.

These are just some of the many passive cooling options available for those who don’t want to rely on their air conditioner for comfort all summer and are looking for ways to reduce their energy costs and environmental impact.