How to make a fan colder and more efficient

On a still summer’s day, a fan feels like a lifesaver. In sultry weather, moving the air around makes rooms feel fresher, and a simple breeze across the skin helps sweat evaporate, keeping you cool. But if you’re still feeling the heat, you’re probably wondering how to make a fan colder and more efficient. Here we look at the best tricks and tips to improve fan performance.

There’s little mystery to the way a desktop, personal, or floor-standing fan works – as its blades rotate, they kick up a draft. Liquids evaporate more quickly in moving air, so our sweat becomes much more effective at keeping us cool. So long as you’re in the breeze, and particularly if you’ve got bare skin, you’re going to notice the difference.

Even so, in the hottest weather it might not feel like your fan’s making much difference – after all, it’s just shifting the same old hot air around. In fact, there are a wealth of ways to improve fan performance, but let’s start with the basics.

Related: Best fan

1. Use the lowest speed possible

First of all, it pays to understand that fans are usually most efficient at their lowest speed setting. Turning up the power shifts more air, but it uses more electricity, generating more heat and noise in the process. Try to stick with the slowest speed that produces an effective draft.

2. Keep it clean

Talking of efficiency, a regularly used fan quickly picks up house dust. This tends to accumulate around its intake vents and particularly on the leading edge of the fan blades. Over time it makes them less slippery, and the fan becomes less effective. Many fans with concealed blades – notably Dyson models – include a serviceable dust filter. If you want to improve fan performance, make sure you check and clean it as recommended by the manufacturer to prevent it restricting the airflow.

Dyson Pure Cool Me filter

If you’ve got a standard fan, check it every month or so and clean off any significant dust buildup. With the fan unplugged, use a duster to remove dirt from around the air intakes and exits. If necessary, unclip or unscrew the blade cover and give the blades themselves a good clean – you might need to look in the manual to find out how to gain access.

If needed you can usually get away with using a damp cloth to wipe the blades and intakes of a fan, but always dry and reassemble the components before plugging the fan back in, and always defer to any cleaning instructions in the manual.

A clean fan should create a much stronger draft, but where should you point it? Opinions differ, particularly when it comes to features like oscillation. Generally speaking, point a small fan at the people who need it, and only use oscillation if it’s not possible to cover everyone without it. More powerful fans can circulate the air around an entire room – try bouncing their airflow off the ceiling, or aiming it along one of the walls to create a consistent, powerful swirl of air.

3. Open the windows – or don’t

So far we’ve assumed there’s not much natural breeze available, but where there is you may be able to turn it to your advantage. Don’t rush into opening up all the windows, though – on very hot days, particularly in the afternoon, your house may be far cooler than it is outside. 

Keep curtains closed on the sunny side of the house, and only open the windows when you know it’s significantly cooler or less humid outside – typically overnight and in the early morning. Use a thermometer or weather station to compare real figures if possible, but failing that, use information from the weather forecast – or simply go by feel.

In breezy conditions, opening the windows alone could begin to cool your home, but in still weather a fan lets you accelerate the process. Open windows on opposite sides of the house, and place fans to either blow air directly out of a sunny window, or suck in air directly from a shaded one. While the latter will create a cool breeze, the former might produce a more powerful through-draft.

4. Turn your fan into a cooler

If you still can’t get cool, you may need to try some more creative solutions. Evaporative coolers use the breeze from a fan to evaporate water, which in turn cools the stream of air – with care you can create something similar yourself.

Begin by finding a thin sheet of cotton or another wicking fabric, preferably with holes in it to allow air through. Soak the fabric, then wring out the excess water. Place it across the seat of a plastic garden chair so that it hangs down on either side, and point a fan so that it circulates air across the fabric. You should find that the damp fabric cools the stream of air as the water evaporates. You can enhance the effect by placing ice packs atop the fabric, and occasionally re-wetting it with cold water – be careful to keep any running liquid well away from the fan.

Alternatively, you could skip the fabric and place ice or ice packs directly in the airflow in front of the fan. One way to achieve this without condensation running everywhere is to place the frozen items on a shallow tray on the ground, then point the fan to blow air across them from perhaps a metre away. You don’t have to use ice – in the summer this is a great way to defrost frozen meals or drinks.

There are other ways to build your own evaporative cooler. It seems a shame not to line-dry washing on a summer’s day, but if you’ve got a clothes dryer or radiator racks, simply pointing a fan at your washing will dry it quickly and create a similar cooling effect. If you find this effective, try selecting a slower spin speed to leave washing wetter. And if you’re already up to date with the washing, just put clean towels through a cold rinse programme using the slowest available spin.

5. Getting through the night

On a hot, still night, a fan can make the difference between sleeping or not. If you’ve got a quiet, powerful fan like the MeacoFan 650 Air Circulator, use a low setting and point it just above the bed to create a gentle circulation of air.

However, some other powerful fans are too noisy to sleep with. Place noisy fans outside your bedrooms, but point them through the open doorway to create a compromise between noise and air circulation. Remember to open up as many windows as possible before you go to bed – with luck you’ll create a fresh enough environment to get a decent night’s sleep, and wake up to a much cooler home.

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