THE battle over the humble thermostat has been tearing friendships apart since air conditioning was invented.
The perfect temperature is a constant source of frustration for Australians who often wished they had brought scarves and gloves on menial trips to offices, cinemas and shopping centres across the nation.
Our obsession with making air conditioning is not surprising, given large swathes of the country have been baking in oppressive heatwaves in recent weeks.
But, our bad habits with this life-changing technology are damaging for the environment and costing us money - to the tune of more than $1.3 billion a year, according to new research from comparison website finder.com.au.
"The typical split cycle air conditioning unit consumes around 5.0 kWh and costs around 2.7 cents to run per minute," said Angus Kidman, energy expert at finder.com.au
"This might not sound like much but a full night's sleep with the air con running can cost close to $13."
The research shows Aussies waste an average of 244 minutes or 4.1 hours per day in energy by leaving their air conditioning running. This works out to cost up to $1.3 billion in wasted energy expenditure over summer while these homes are sitting empty.
More than 2.3 million households will waste power in Australia by keeping their air conditioning running when not home - which adds an average of $578 to their quarterly bill.
Mr Kidman says that cutting down air conditioning use by just half an hour a day can save households up to $72 over the three months of summer, depending on how much cooling is required.
It is easier said than done for the manager of the iconic Birdsville hotel in Queensland's far southwest, Ben Fullagar, who said he has to have the air conditioning running constantly until summer has passed.
The remote town has seen the mercury hit tops of 45C in this week's nationwide heatwaves.
"Pretty much once this heat starts this week we don't really turn our air conditioners off until March or April, because basically if you turn them off, it's too hard for them to cool the place down again the following day," Mr Fullagar told ABC.
THE PERFECT TEMPERATURE
If you really can't turn the air conditioning off then you should at least adjust the settings to 25C in summer and 19C in winter, argues Tony Crabb, national head of research at real estate services firm Savills Australia.
He said thermostats across the world are often fixed at 22 degrees - which, he argues, is costing the economy billions of dollars and pumping hundreds of thousands of tonnes of unnecessary carbon into the atmosphere.
If we all stuck to the 19C and 25C rule, Australian businesses could save $100 million and 300,000 tonnes of carbon every year, he argues.
"The built environment is heated and cooled to a fixed 22 degrees regardless of the temperature outside," he said during a TEDx presentation.
"It turns out, that's the thermal comfort level of a 44-year-old man. It was decided by the Americans in the 1950s, and it's been that way ever since."
"While human beings adapt to heat or cold by wearing more or less clothes, we don't ask our buildings to adapt.
"The [22-degree setting] is so embedded in the psyche of the world that it's legally written into leases," he said.
"But why? The thermal comfort level of a human being depends on whether they're male or female, what age they are, whether they're tall, short, fat or skinny. There isn't one-size-fits-all."
- with Frank Chung