When summer arrives and temperatures climb, so does the question: should you run a fan or reach for the air conditioner? The short answer is that fans use far less energy — but the full picture is a little more nuanced. Here's a clear breakdown to help you make the smartest choice for your home and your energy bill.
How much energy does a fan use?
A standard electric fan uses between 15 and 100 watts depending on the type and speed setting. To put that in context:
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Desk fan: 15–35 watts
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Tower fan: 40–60 watts
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Pedestal fan: 50–100 watts
Running a tower fan for 8 hours a day at 50 watts costs roughly 4–5p per day at average UK energy rates approximately 28p per kWh. Over a full month, that's around £1.20–£1.50.
How much energy does an air conditioner use?
A portable air conditioner typically uses between 900 and 1,500 watts. A split-system wall unit can use anywhere from 700 to 2,500 watts depending on the room size and model. Running a portable AC at 1,200 watts for 8 hours a day costs roughly £2.69 per day — nearly 50 times more than a fan.
So why would anyone use an air conditioner?
Because fans and air conditioners do fundamentally different things. A fan moves air and creates a wind-chill effect — it makes you feel cooler, but it does not lower the actual temperature in a room. In very humid conditions or extreme heat, moving hot air around only does so much.
An air conditioner removes heat and moisture from the air, physically reducing the room temperature. In countries with hot, humid summers, that makes a real difference to comfort and sleep quality.
The verdict: when to use a fan
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Temperatures are below around 35°C
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Humidity is moderate
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You want to keep energy costs low
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You're looking for background comfort rather than intense cooling
The verdict: when an air conditioner is worth it
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Temperatures consistently exceed 35°C
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High humidity makes the heat feel oppressive
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You need to cool a room to sleep properly
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Someone in your home has a health condition worsened by heat
The smart approach: use both
Many households get the best results by using both — running an air conditioner to cool the room and then switching to a fan to maintain comfort once the room has reached a comfortable temperature. This cuts AC running time significantly and reduces energy use without sacrificing comfort.
Energy-efficient fans from Dimplex
Dimplex fans are designed to deliver maximum airflow for minimum energy consumption. Browse our full range of fans at shopdimplex.com and find a fan that keeps you comfortable without running up your energy bill.