The average Aussie home uses 9-29% of their energy on cooling each year (via Origin) and air conditioners are mainly responsible for this power suck–‘[t]he energy an average air conditioner uses in 3 hours is enough to power a fridge for a week’ (via Green Times)–so it makes sense to go air-con-less in order to minimise the power bill.
You might want to consider some old-school alternatives of staying cool, however, before the temperature inside your home creeps over thirty-five degrees and your resolve melts into mush.
- Summer wardrobes – In Ancient Egypt, men wore wrap-around skirts or went about naked while women wore loose-fitting dresses. Garments were made out of linen, a lightweight, natural fabric that breathed. I’m not advocating nudity or skimpy/see-through dresses but we can all certainly opt for the modern equivalent of ancient Egyptian linen without causing too much of a scandal.
- Window screens – In India, latticed screens or jaali filtered direct sunlight around windows. ‘The effect was decorative and helped reduce the heat’ (via CNN). Installing awnings, external shutters or louvres, or even planting a deciduous hedge in front of north-facing* or west-facing sections of your house will help you combat the heat. Sustainable Energy Authority in Victoria has put together a fact sheet on how to minimise excessive summer heat gain through windows.
- Windows of opportunity – Before fans and air conditioning, people habitually closed windows, curtains, and or shutters during the hottest part of the day to keep out the heat. When temperatures dropped overnight, the windows were thrown open so that the heat inside could dissipate. You can train your household to do the same. Just remember to seal all gaps around the windows and doors to make them more thermally efficient. Also install flyscreens and security screens so that no opportunistic intruders (six-legged or otherwise) can take advantage of those open windows.
- Passive ventilation – Houses in warmer climes were built to make the most of passive ventilation. Traditional Queenslanders were built on stilts to encourage a cool breeze underneath the house. Doors and windows were aligned to maximise cross-ventilation. A steeply pitched roof also allowed the warm air to rise and escape. While it’s expensive (and unnecessary) to raise a Melbourne house or change it’s roofline, we can still make the most of cross-ventilation by opening windows or doors on opposite sides of a room or house. Check out Carolyn Boyd’s article for more information on how to make it work for you.
- Hotspot avoidance – ‘This must be a most inconvenient sitting room for the evening, in summer; the windows are full west’, Lady Catherine de Bourgh declares in Jane Austen’s Pride and Prejudice, demonstrating how clued in Regency people were when it came to passive heating and cooling. They knew which parts of a building were heat traps and how best to use/avoid them. If you’ve lived in a house for more than one year, you will probably know its hot spots (i.e. the top floor, or a west-facing room). Try not to use these in summer. Instead shut them off from the rest of the house. Conversely, in winter, such rooms should be utilised to make the most of the free warmth.
- Sensible salads – There’s a reason why traditional Vietnamese cuisine is accompanied by a platter of leafy greens. Can you imagine trying to eat a hot phở in the middle of a Hanoi summer? Salad sounds like a more refreshing option. It also avoids the use of a stove. Yep, why add to the heat when it’s hot already? While you’re at it, don’t forget other summery treats that help you feel cool like jelly, frozen fruit, and homemade icy-poles.
- Fans – Like cross-ventilation, fans move air around, allowing our sweat to evaporate and cool us down faster. Initially human-powered, they became mechanicised in the 1870s. Since they only move air instead of cooling it, they have comparatively low overheads. A fan only costs 1.5c/hour to run; an air-conditioner costs 30-91c/hour to run (via ResourceSmart).
*Or south-facing if you’re in the northern hemisphere.