DIY cooling hack: Beat the summer heat with a homemade air conditioner

Air conditioning is standard in many offices but is still missing in most residential buildings, especially older ones. Summer temperatures can be very high, so an effective way to cool down at home can be precious.

Interestingly, it doesn’t take much to improve your thermal comfort dramatically. If you have an ordinary fan, you already have the most essential element to create a homemade air conditioner. All you need is cardboard, a little free time, and, for the more determined, polystyrene foam.

It’s important to remember that basic physics remains unchanged—the only way to cool down a room is to supply cold air or remove heat. Other methods only temporarily improve thermal comfort.

That’s why when we turn off the fan, the heat returns quickly - the feeling of coolness comes from the flowing air, while the actual temperature in the room does not change.

Our proposed method works differently, but it is still a temporary solution. It involves modifying the fan to work similarly to a fan coil unit. You’ll need cardboard, preferably lined with polystyrene foam, some ice, and a fan.

The fan should be encased in cardboard as tightly as possible. Lining the cardboard with polystyrene foam is advisable - it prevents the cardboard from getting soaked by melting ice and helps insulate the fantastic elements from the warm outside air.

The concept is simple: Place ice inside the cardboard and mount the fan in front of it. The tightly enclosed fan draws in the cool air inside our construction and directs it to a chosen location.

Of course, this solution won’t cool down the entire room, just the places where you direct the stream of cool air. Although it’s not a full-fledged substitute for air conditioning, it can bring us temporary relief during the hottest moments of the day.