“Heatwaves are occurring across the country, but just because it’s warming up doesn’t mean we need to fall victim to bill shock,” a Finder spokesperson said.

The survey asked 2,017 people questions in relation to their air conditioner use and found 23 percent of users – the equivalent of 2.3 million households – admitted they left the air conditioner on.

“Aussies are predicted to waste over a billion dollars this summer due to bad air-con habits,” the spokesperson said.

”Those Aussies that are partial to air-con indulgence waste an average of 4.1 hours in energy per day.”

Finder believes this works out to cost up to $1.3 billion in wasted energy expenditure over the summer months while homes are sitting empty or an added $578 per household to quarterly electricity bills.

Bessie Hassan from Finder said for some people the consequences are brushed aside as the heat is too much to bear.

“When faced with a heatwave and temperatures as high as 40 degrees, we don’t usually think of our electricity bill some three months away – we just want to instantly cool down.

“But after a few scorchers, this way of thinking can leave you with post-summer bill shock.”

According to Finder the typical split cycle air conditioning unit consumes around 5.0 kWh and costs around 2.7 cents to run per minute, which can cost close to $13 per night if left running overnight. 

“There are more wallet-friendly ways to keep cool in summer such as keeping blinds closed during the day to keep the sun out and opting for a fan instead,” Ms Hassan said.

“If you find you really can’t live without air-con invest in a timer. That way you can set it to turn off once you fall asleep.”

The survey found 18 to 22-year-olds are the least savvy when it comes to air conditioning costs and keep the cooling running for 5.6 hours a day on average while not home. 

In comparison Millennials only waste four hours, Gen X waste 3.6 hours, and Baby Boomers indulge in 4.2 hours of cooling while not at home. 

The survey showed women are slightly more prone to air-con over-indulgence, wasting on average 253 minutes per day, in comparison to men who waste 233 minutes.