Air conditioner vs ceiling fan: the gap is bigger than you think

Everyone knows the fan is cheaper. Almost nobody knows by how much, which is a shame, because the size of the gap is what makes the decision easy.

Eight hours of cooling, on New South Wales reference rates:

Split-system air conditioner850W, 8h per day of use	$2.25 per day of use	$270 a year
Ceiling fan70W, 8h per day of use	19c per day of use	$22 a year

A 2.5kW-cooling split system pulling about 850W costs roughly $2.25 for an eight hour stretch. A ceiling fan at 70W costs about 19 cents for the same eight hours. The fan is around twelve times cheaper, and over a 120-day cooling season that is the difference between about $270 and about $23.

The honest catch

A fan does not cool a room. It moves air across your skin, which makes you feel about three degrees cooler than the thermometer says. That is a genuine and underrated effect - but it only works on people. The fan does nothing for a room that is already 38°C, and nothing at all for a room with nobody in it.

So the comparison above is not quite fair, and the fair version is more useful:

• Under about 30°C, the fan usually wins outright. You get the comfort you wanted for a twelfth of the cost.
• Above about 35°C, the fan is not a substitute. Running it instead of the air conditioner is not thrift, it is just being hot.
• In between, run both. This is the part people miss. A fan lets you set the air conditioner two or three degrees higher for the same comfort, and each degree is worth roughly 5 to 10 per cent off the cooling bill. The fan’s 19 cents buys back considerably more than 19 cents of compressor time.

Where the real money is

If you want to cut a cooling bill, the split system is not the villain - the ducted system is. A whole-house ducted unit draws around 4,200W, which is five times the split system:

Ducted reverse-cycle air conditioning: 4,200W, 8h per day of use, 90 day of uses a year

State	Rate	Per day of use	Per year
Tasmania	27.95c	$9.39	$845
Queensland (south-east)	27.97c	$9.40	$846
Victoria	28.2c	$9.48	$853
Northern Territory	31.68c	$10.64	$958
New South Wales	33.14c	$11.14	$1,002
Western Australia	33.26c	$11.18	$1,006
Australian Capital Territory	36.95c	$12.42	$1,117
South Australia	41.91c	$14.08	$1,267

Eight hours of ducted cooling costs over $11 a day in New South Wales and over $14 in South Australia. Ninety of those days runs from $845 in Tasmania to $1,267 in South Australia. Cooling one occupied room with a split system and a fan instead of the whole empty house is, by a distance, the biggest summer saving available to most households.

Assumptions

Figures use flat 2026-27 reference rates and exclude the daily supply charge. Air conditioner draw varies enormously with outside temperature, thermostat setting and how well the room is sealed; 850W is a reasonable average for a 2.5kW-cooling inverter unit doing steady work, not a nameplate maximum. Our full method is here.