5 mistakes everyone makes with fans: don't let the heatwave ruin your week

Thinking of buying a new fan? Don't make these five fan foul-ups and make the heat beat a retreat

5 mistakes everyone makes with fans
(Image credit: Getty)

Do you feel the temperature rising? Here in T3's native UK, we are on the verge of a 'heatwave'. This is what much of the world just calls 'summer', but there it is. Most of the northern hemisphere is seasonably hot, and some of it is too hot for comfort, and that is always when fan buying kicks off in earnest. We always recommend that people buy a fan before it gets really hot and demand starts to outstrip supply, but we know from our annual traffic figures that, regrettably, nobody pays attention to those wise words.

Needless to say we have a guide to the best fans, and also one for the best Dyson fans specifically. In parts of France, Spain and much of the USA it's hot to a level that is genuinely dangerous, so perhaps a fan is not sufficient – move right along to the best portable air con units, in that case.

Whatever you do, though, don't buy or operate a new fan before you've contemplated the following mistakes that (almost) everyone makes with fans.

1. Thinking a fan will cool your house

Duux Whisper Flex

Even this fine specimen from Duux won't save you in a real heatwave

(Image credit: Duux)

Well, that's put a dampener on things straight away, but it's true. When it gets really hot, all a fan will do is move the hot air around at medium to high speed. I once wrote some words for an advert for a fan by a certain well-known brand, and was told in no uncertain terms that I couldn't use the word 'cooling', because it was not an accurate way to describe what the fan does. 

So why bother at all? A very fair question. The simple answer is that hot, moving air is preferable to even hotter, non-moving air. The sense of a having a breeze is refreshing in itself and if you are close enough to your fan, the blast of air will cool your skin even if it doesn't appreciably cool the air in the room as a whole. 

However, that being said, I still think you should buy a portable air conditioner rather than a fan if you want to really feel cool in truly scorching weather.

2. Putting your fan on the window sill

Couple who are too hot in front of fan

Window? No! This is more like it…

(Image credit: iStock/Getty)

Due to the powerful hand of thermodynamics, this is an unwise choice. Unless something has gone drastically wrong, the inside of your house should always be cooler than the air outside it. Placing a fan immediately next to a window, whether open or closed, will therefore usually mean sucking air into your living space that is hotter than what's already there. So don't do that.

Also, for the same reason, your curtains and blinds should be closed in hot weather anyway. Clearly, placing a fan on your window sill behind a curtain is even more of a waste of effort. 

3. Pointing your fan OUT of the window

This is a popular 'hack' for cooling your home and in theory it does make sense: pointing a fan out of the window should expel hot air, rather than simply moving it around. 

However, if you think about this for even a moment, you will realise that the impact this will have – if any at all – is absolutely tiny. If your window is open only a crack, hardly any air can be expelled through it, and if your window is open fully, you will need an incredibly powerful fan to push out more hot air than is able to come in. It would need to be like a bloody wind machine, in fact. 

In terms of physical and psychological effect, pointing the fan into the room – and at yourself, more to the point – is the only way to go. 

4. Buying a fan that's just a fan

Dyson Purifier Humidify + Cool

This fan is useful all year around

(Image credit: Dyson)

A while back, Dyson hit on the rather cunning ruse of making fans that are also heaters – okay, they did not invent that idea; fan heaters have been around for years. However, they then started making devices that are various combinations of fan, heater, air purifier and humidifier. 

Although these fan hybrids are naturally more bulky and expensive, they have the considerable benefit of being useful all year around. A fan that's just a fan, bought during a heatwave, is likely to gather dust as soon as it gets cooler again – and that will be pretty soon in the case of the UK, let's face it.

5. Running your fan 24/7

MeacoFan 1056 Air Circulator review

(Image credit: Meaco)

Given the cost of electricity right now, this seems highly unwise. As we were discussing just now, fans don't appreciably lower the temperature of the room they're in, so there is minimal benefit to leaving them running while you're out of the room, and potentially significant costs. 

If you're worried about the size of your next electricity bill, it makes sense to turn fans off when you're not in the same room as them. Another option is to buy a portable, battery-powered fan and take it with your from room to room. Or get one of those novelty hats with a fan in them – they're both chic and practical. Okay, maybe not.

Some fan deals right now

Duncan has been writing about tech for almost 15 years and fitness ever since he became middle aged and realised he could no longer rely solely on his boyish good looks. He used to be on telly loads, but an unfortunate incident put a stop to that, so he now largely contents himself with telling people, "I used to be on the TV, you know."
Pre-lockdown Duncan was widely regarded as the best-dressed man ever to work for T3 – admittedly not saying much. Post-lockdown he is looking forward to wearing clothes other than shorts and hoodies again very soon, assuming he can still fit into them. He currently writes about cycling, fitness tech that isn’t too heavy, and all things kitchen and home related.