It’s the summer dilemma: you’re sweltering while staring longingly at the air-conditioner but the thought of a stratospheric electricity bill doesn’t quite let you push the ‘on’ button.
It’s not just you. A survey last month by consumer ratings agency Canstar Blue found more than half of Aussie households cut their AC usage in 2016 to save on the bills.
But the temptation is still there on super-hot days, so we asked AC expert Glenn Townsend for some tips on how to use air-conditioning in the most energy efficient way. Townsend is the vice president of AREMA, as the Air-conditioning and Refrigeration Equipment Manufacturers of Australia is known, as well as being on staff at Toshiba, so he knows his coolers. Here’s what he told us.
Clean the filter on your air-conditioner, as often as every eight weeks if you use it regularly, by washing it with soap and water or vacuuming it. A clean filter puts less strain on the unit’s fans, which means it works more efficiently, thus requiring less power.
Townsend recommends trying to tolerate a temperature a degree or two higher than your ideal comfort temperature, because the more an air-conditioner must work to reduce a room’s temperature to the setting, the more electricity it uses.
“It’s like taking your car for a shorter trip, you’re using less fuel,” he explains.
Canstar says the ideal temperature to maximise the energy efficiency of your unit depends on your local climate.
For example, residents of south east Queensland and north east New South Wales should set their AC at 25 degrees in summer, while south east NSW, north east Victoria and the ACT should aim for 26-27 degrees, 28 degrees is sufficient for Tasmania, and 23-24 degrees is right for south west Western Australia and 24 degrees in south Victoria.
Canstar recommends checking out how much you can save by moving your temperature a degree or two by using the Ergon cost calculator.
Townsend says it’s key to close doors and windows and even pull the blinds or curtains of the room or area you want to cool “otherwise you’ve got 41-degree air blowing through the door that you’re paying to cool.”
This is particularly important if you’ve got windows facing the western sun, he notes.
Townsend is adamant on this point: it’s a must to insulate any room you want to cool “otherwise 30 percent of the energy will go through the ceiling of an uninsulated space.”
If your AC units are more than 15 years old, it may be time to consider swapping them for far more energy-efficient recent models, according to Townsend.
Canstar says that split-system air-conditioners are the most energy efficient type of cooler, while the older-style window AC units are less so, with energy star ratings usually around the two-star mark or lower.
Townsend admits that even industry pros can’t agree on whether it’s kinder to your electricity bill to shut up house and whack on the AC at the first sign of a scorching day, or to wait until the heat peaks then turn on the air-conditioning and crank it up to full blast.
“It’s the equivalent of putting the foot down in the car to go five kilometres faster to get somewhere quicker or steadily increasing your pace over a longer distance.”
But, speaking personally, Townsend recommends the slow-and-steady approach of putting the AC on early at a moderate temperature, then adjusting the temperature lower only if the heat outside increases dramatically.
Canstar points out that, while built-in AC is getting cheaper, there are other, less expensive options, such as evaporative coolers (cool the air through the age-old method of evaporating water), ceiling fans and portable air-conditioners.
Then there are the truly low-cost solutions, such as soaking your feet in cold water, placing a bowl of ice cubes in front of a fan as a DIY air-conditioner, hanging a damp sheet in an open window, and turning off all heat-producing appliances such as the dishwasher and clothes dryer.