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Beat the heat wave — how to make your own air conditioner in 3 easy steps

an image showing a thermometer during a heatwave
(Image credit: Shutterstock)

Whether your air conditioning is broken or you’re in a room without windows, you can easily learn how to make a DIY air conditioner. This is especially the case if you’re working from home on a humid day, and want to cool down a room. Or if you simply want to sleep better in a heatwave without waking up more tired. 

And while there are tons of hacks online, we’ve found the easiest method for how to make a DIY air conditioner that will take no time at all. Best of all, you won’t have to spend a fortune on expensive or complicated gadgets. All you’ll simply need is a fan and plastic water bottles! 

So if you want to keep cool, here’s how to make a DIY air conditioner to beat the heat, in just three easy steps. Also, be sure to check out 5 essential tips for keeping tour lawn green in a heat wave (opens in new tab) and how to use a $2 roll of aluminum foil to beat the heat.

1. Fill plastic bottles with water and add salt

Plastic bottles in a bag

Plastic bottles in a bag (Image credit: Shutterstock)

First, fill two or three plastic water or soda bottles with water, and pour three tablespoons of salt (51g) into each. Replace the caps on before shaking each bottle to ensure the salt is thoroughly mixed into the water.  

2. Put bottles in freezer

Frozen bottles of water

Frozen bottles of water (Image credit: Shutterstock)

Next, put the bottles into the freezer, and leave them until they are completely frozen. The salt inside will lower the freezing temperature of the water, making the ice colder. Take the bottles out of the freezer once the water turns to ice.  

3. Place frozen bottles in front of fan

Frozen bottles in front of a fan

Frozen bottles in front of a fan (Image credit: Shutterstock)

Then, place the frozen bottles right in front of your electric fan, about 6 inches away. Turn on the fan, keeping it pointed towards the water bottles, and the air should feel cooler once it passes around the frozen bottles. A desk/table fan will work best, but you can use any fan that is height adjustable. Simply put the bottles on a table in front of a standing fan. Once the ice melts, simply put the bottles back into the freezer again.You can always prepare multiple bottles in your freezer, so you won’t have to wait for your instant cooling.

And there you have your DIY air conditioner that's easy to make, and will cool you down in a heatwave!

How to make a DIY air conditioner: Hanging bottles behind fan 

table fan on wooden table

table fan on wooden table (Image credit: Shutterstock)

Another alternative is to hang bottles behind your fan.

1. First, take your empty, plastic water or soda bottles and cut off the end, about 1 inch (2.5 cm) up from the bottom with a utility knife. Next, carefully punch a row of holes in the sides with a screwdriver or pointed tool.  

2. Then, tie the bottles upside down at the back of your fan with a string or wire put through two of the holes in each bottle. Ensure the fan is turned off before securing one bottle on either side of the motor compartment.

3. Next, fill the bottles with ice cubes just below the holes, before turning on the fan. This will pull in the cold air through the holes, and cool the room.Since the bottles are tied securely to the back of the fan, you can set it to oscillating mode. Once the ice melts, simply remove the bottle cap and place a bowl underneath the nozzle to catch the water. Then you can just replace the ice in the bottles. 

Other tips for cooling a room 

A woman trying to keep cool in front of an electric fan

A woman trying to keep cool in front of an electric fan (Image credit: Shutterstock)
  • Keep the curtains and blinds closed during the day to keep out the heat
  • Similarly keep doors closed to trap cooler air 
  • Hang damp sheets in front of open windows. The moisture from the sheets should help to cool any breeze coming from outside
  • Buy one of the best cooling mattresses to help you sleep at night
  • Open windows and doors at night once the temperature drops 

If you’re looking to invest or upgrade your air conditioning, check out one of the best smart air conditioners, as well as the best air conditioner deals. You can also learn how to clean an air conditioner with these simple steps.

Looking at more tips to beat the heat? Check out the top 7 deals to help you stay cool and beat the heat. You can also read about how my iPad let me work while beating a heat wave

Cynthia Lawrence
Cynthia Lawrence

Cynthia Lawrence specialises in Homes ecommerce, covering all things homes and garden-related. She has a wealth of editorial experience testing the latest, ‘must-have’ home appliances, writing buying guides and the handy ‘how to’ features. 


Her work has been published in various titles including, T3, Top Ten Reviews, Ideal Home, Real Homes, Livingetc. and House Beautiful, amongst many.


With a rather unhealthy obsession for all things homes and interiors, she also has an interior design blog for style inspiration and savvy storage solutions (get rid of that clutter!). When she’s not testing cool products, she’ll be searching online for more decor ideas to spruce up her family home or looking for a great bargain!