On a sticky day the ceiling fan is the first thing most people switch on, often instead of air conditioning. But how much cooler does it really make you feel, and what does it cost to leave running for hours on end? The answer overturns a very common misunderstanding: a fan does not lower the room temperature by a single degree, yet it can make you feel several degrees cooler. Understanding why helps you use it well and avoid wasting power.

How many degrees cooler it feels

A fan does not cool the air, it moves it. That movement speeds up the evaporation of sweat on your skin and breaks up the thin layer of warm air around your body, so you feel cooler than the room actually is. The effect is typically worth 3 to 4C in perceived terms, enough to make a room at 28C comfortable without switching on the air conditioning. The thermometer itself does not budge, which is exactly why running a fan in an empty room does nothing at all. It cools people, not walls.

One detail few people know: in summer, ceiling fan blades should turn anticlockwise, so they push air downward and create the breeze you feel on your skin. Most models have a small switch on the housing to reverse the direction between summer and winter. With the blades spinning the wrong way, the cooling effect is almost entirely lost.

What it costs to run all day

Here is the real surprise. A ceiling fan draws around 50 to 70W, against the 800 to 1000W of a portable air conditioner. Under the Ofgem price cap for 1 July to 30 September 2026, electricity costs about 26p per kWh, so leaving a fan on for a full 24 hours costs roughly 37p a day, compared with several pounds for a cooling unit. That is the gap between a few pence and a line that actually shows up on your late-summer bill. Over a whole month the fan stays under about 12 pounds, while an air conditioner used just as freely can cost ten times as much. To see how different appliances compare, our guide on how to save electricity is a useful starting point.

How to use it well

The smartest move is to combine it, not replace everything with it. A ceiling fan pushing air downward lets you raise the air-conditioning thermostat by a couple of degrees while feeling just as comfortable, and every degree higher on the thermostat noticeably cuts your cooling costs. At night, with the windows open once it is cooler outside, a fan helps circulate that fresh air and flush out the heat the house has stored during the day. Fan on when you are in the room, off when you leave, and the thermostat set a little higher: that is the recipe that pairs comfort with a lighter bill. If you are weighing up a purchase, there is a wide range of ceiling fan models to suit any room size. For the wider picture, our air conditioning guide sets out when cooling is worth the cost. A fan is not a poor relation of air conditioning: it is the right tool when the goal is to feel cool while spending as little as possible.