The Best-Value Way to Keep Cool
Air coolers are increasing in popularity with every passing summer. It’s easy to see why – they offer much more cooling power than an electric fan while being significantly more affordable (to both buy and run) than an air conditioner while also being lightweight and easy to use. It sounds almost too good to be true; how can something offer all this at such a low price? It’s all to do with the natural process used by air coolers to chill rooms. By understanding the science behind it, you’ll be able to make a more informed choice when picking up an air cooler!
Evaporative Cooling
Air coolers work using a process called evaporative cooling. This is an entirely natural process, meaning an air cooler doesn’t need to use complex, expensive machinery to chill the air. All that you’ll find inside an air cooler is a tank of water, a small pump, and an absorbent pad.
How Evaporative Cooling Works
When water evaporates, it changes from a liquid to a gas. This gas – water vapour – is absorbed by the air. You probably knew this already, but what you might not know is that when water changes state and is absorbed into the air, it causes the air to lose heat energy. This is why the wind gets so cold as it blows in from the ocean or across a lake.
Air coolers use a tank of water, a pump system, an absorbent pad, and a fan to artificially create a system where water is constantly evaporating to chill the air. The pump system takes water from the tank and sprays it onto the absorbent pad. It doesn’t soak the pad, but lightly wets it to ensure the moisture it holds evaporates quickly. In front of the pad, you’ll find an electric fan. The fan pulls in warm, dry air through the back of the unit and, crucially, through the pad. The water on the pad evaporates, which cools the air before the fan pushes it out into the room.
Extra Cooling Power
All of this gives air coolers an extra edge over electric fans. Despite what you might think, fans don’t actually lower the temperature of a room – they just create a cooling effect by moving air around. This is fine if you just want to keep yourself comfortable, but if you want to actually lower the room temperature as well, you’ll need an air cooler.
Humidifies the Air
As you might imagine, evaporative cooling also humidifies the air as it cools it. You might think this is the last thing you want when you’re trying to cool down, but humidity can actually be a good thing! This misconception comes from the fact that the warmer air is, the more moisture it can hold. This means hot air is usually humid, but humid air isn’t always hot. If a room has a healthy airflow, you won’t be affected by the humidity.
One major benefit of humidifying the air is that it helps to purify it. Humid air is full of negative ions, which bind themselves to dirt and impurities in the air and give them a tiny negative charge. This charge causes these particles of dirt to cling to surfaces (the same way rubbing a balloon on your hair creates a charge which makes them stick together) so they won’t be circulating around in the air that you breathe.
Eco-Friendly
Evaporative cooling is a natural process. This means they’re considered more eco-friendly than air conditioners as they don’t use refrigerant gas and barely use and energy to run. They’re good for the planet and good for your energy bills, too – you can run an air cooler all day long for around 2-3p per day (depending on your energy tariff).
Do You Need an Air Cooler?
If your old fan isn’t cutting it any more, you can definitely benefit from an air cooler. On very hot days, a fan might not help much as all it’ll do is circulate warm air around the room. An air conditioner would be ideal, but, for many people, they’re simply too expensive to be a realistic option. An evaporative air cooler occupies the perfect middle ground between the two – they lower your room temperature and encourage a healthy airflow, but they don’t cost the earth.
While air coolers are much more affordable than aircon units, there is a trade-off. Air coolers aren’t as powerful as air conditioners and you shouldn’t expect the same instant blast of ice-cold air from them. If you have a massive open space that you need to cool – such as an open-plan office, a warehouse, or a gym – you’ll be better off with an aircon. However, if you have a medium-sized room that gets too hot for a fan to be effective – such as a bedroom or a south-facing office – an air cooler is the ideal choice.
