Dr Negin Nazarian, an award-winning researcher in urban heat from UNSW Sydney, shares her expertise to help us keep cool at home.
Dr Negin Nazarian, from the School of Built Environment at UNSW, is an expert in urban heat. We asked her how the science behind urban heat research could help us keep our homes (and therefore ourselves) cooler over summer.
1. Insulation, shades and blinds can keep things cooler
“On a hot sunny day, the winning strategy is to stop the heat from getting into your space,” says Dr Nazarian. “Cooling is harder once your home has heated up. In the urban environment, any way that radiant heat from the sun can be prevented from being absorbed by surfaces or heating a space is key to keeping cool in the face of high temperatures. In urban environments this looks like designing buildings using effective insulating materials, orienting larger windows to be north rather than west facing, using awnings or shades that can be adjusted, and ensuring windows are double glazed, tinted or shaded to prevent radiant heat getting into the space.” The Australian Government’s Guide to Environmentally Sustainable Homes says up to 87 per cent of a home’s heat is gained through windows, so improving the thermal performance of windows is a great way to keep cooler.
Take home tips:
- Blinds, shutters and awnings can all stop heat from entering your home, so keep them drawn when the sun is hitting them. Remember to close them before you leave the house, if you won’t be home at the hottest part of the day!
- Proper insulation doesn’t only keep your home warm in winter; it also keeps it cool in summer by trapping cool air inside. Insulate your roof and walls and floors if possible to prevent heat transfer.
- Upgrade your windows to better insulate your home.
- You can also use reflective window films to reduce solar heat gain significantly by blocking the sun’s heat.
Double-glazed windows, curtains and shades stop radiant heat getting into your home. Up to 87 per cent of a home’s heat is gained through windows so if you can improve the thermal performance of your windows you will keep your home cooler. Photo: Getty Images.
2. Make use of natural ventilation
“When looking at heat mitigation in urban settings one of the factors that can help lower temperatures and keep people cooler is planning settings that ensure buildings are oriented to take advantage of breezes that come from the ocean, or ponds, dams and lakes. Another is to ensure there is space between buildings to allow for ventilation which moves heat out of the urban environment,” says Dr Nazarian. “Now, while you can’t change the location of your home to catch the ocean breeze, you can certainly try to create avenues for air to pass through. This means when you open a window, open a door and a window on the other side of your home too, to create cross-ventilation and allow air to move through your home.”
Take home tip:
Take advantage of any cool breezes during the early mornings, evenings and overnight. Open windows on opposite sides of your home to create cross-ventilation. This allows fresh air to flow through and hot air to escape. And when the wind is hot, close those windows to keep cooler air trapped in the house if possible. You can also check the weather stripping on doors and windows to keep the cool air in.
