The DIY Air Conditioning Hack That Can Help You Keep Cool

Man sat in front of desk fan
(Image credit: Getty Images)

DIY air conditioning hacks are a great way to stay cool and save money. When temperatures are hitting the high 30s and beyond you'll try anything to try and stay cool and avoid the sweltering heat.

If you are looking for quick and cheap alternatives to home air conditioning this summer, there are plenty of simple options to cooling your home, like keeping curtains or blinds closed or opening windows and rooflights at night when it's cooler to purge the house of hot air. Good choices, but for a more instant hit of cold cooling air you want your very own DIY air conditioning unit.

Here we take a look at a simple hack that’s quick to put into operation and cheap to complete. But was it really any good and did it work? We reveal how to put this hack into action and the benefits.

DIY Air Conditioning: What's the Hack?

If you are looking for tips on how to keep your house cool in summer, then this is one hack to try. For this hack you'll need a fan — an oscillating desk fan, the bigger the better, on a short stand is a good choice as it's easy to work with. But it can be used with any fan.
What you’ll need:

  • Electric fan
  • 3 x recyclable water bottles

1. Fill and freeze water bottles
Get yourself three empty water bottles, ideally recyclable plastic ones you were going to throw away. Fill with water and add a couple of tablespoons of salt. Why? Adding salt lowers the freezing point of water by a few degrees. This effectively means that the frozen water bottles will be slightly colder when in action. Put on the caps and put them in the freezer.

2. Set up in front of fan
Once the water bottles are fully frozen – leaving them overnight is a good option –take out the freezer and set them up in front of your fan. Spread the bottles evenly across the width of the fan and don’t put too close — this will disturb or block the airflow.

Raise up – safely place on a small box, books or similar – so the whole height of the bottle is in front of the fan. The air will hit the frozen water bottles and cool down the air as it passes by.

Fill up an additional three bottles and keep them in the freezer as backup. When the bottles in use have melted you can do a swap, so you have constant cold air.  

Three bottles of water in safe distance from electric fan to cool room

(Image credit: Future / Steve Jenkins)

How Did we Rate this Air Conditioning Hack? 

We are never quite sure what to expect from a hack. Some we have tried worked really well; some we have tried have failed completely and don’t work at all. So how did this DIY air condition hack fare? 

It fell somewhere in the middle. It worked about as well as we expected. It definitely won’t replace the real thing, but we say give it a go. Here we take a quick look at the pros and cons.

DIY Air Conditioning Pros?

  • Cheap to put into operation
  • Can set up in seconds
  • Adds extra cooling to a fan

DIY Air Conditioning Cons?

  • No temperature control
  • Only last three or four hours at a time
  • Only lowers the air temperature by a few degrees

DIY Air Conditioning Alternatives: What Are They?

When it comes to alternatives there are a few — some simple, some not so. Here's a couple to try out.

The simple DIY air conditioning alternative
The very simple alternative to the frozen water bottles is a bowl of ice. Get a large bowl of and fill with ice and put (a safe distance) in front of your fan. You will need a steady supply of ice to replace every time it melts.

The not so simple DIY air conditioning alternative
This involves a styrofoam cool box, a couple of dryer vents – or two plastic offset downpipes – and a small fan. On the lid mark the outline of the fan in the middle and the vents/pipe on either side. Not get a serrated knife or small saw and carefully cut out.

Fill the cool box with frozen bottles of water or ice packs, put the lid back on and place the fan and vents/pipes in the cut outs. The fan needs to point down to blow the cold air out the vents. Position the vents/pipes to where you want them to go and enjoy the cold air.

The not DIY at all alternative
If you are keen to keep yourself cool but are not convinced that a DIY option is for you, why not check out some of the best portable air conditioners on the market. These will definitely cost you more, but they will be ready and waiting for  you for the next time temperatures soar.    

Steve Jenkins

Steve is Homebuilding & Renovating's DIY content editor, and has been a writer and editor for two decades. He is an avid DIYer with over 20 years of experience in transforming and renovating homes. He specialises in painting and decorating, but has strong all-round building skills, having previously worked in the industry for 10 years.