I love a British summer, but (without jinxing it) this heat is a bit much. After a hard day’s work, followed by wrestling through tourists in Leicester Square, sardine-ing myself on to a train and then finally reaching home, I want to cool down and relax. There’s no such luck with this ongoing heatwave.
I find myself taking refuge in the bedroom most evenings, with the shades drawn, window open and the fan running, trying my best to lower the temperature. So, when I stumbled across GH’s DIY air conditioner hack, I was admittedly sceptical but desperate. I had to give it a go to see what a difference it could make, if any. Here’s what happened.
How to make a DIY air conditioner
There’s very little required to make a DIY air conditioner; in fact, I already had everything I needed at home.
The first step involves filling and freezing a large empty plastic bottle with water – you could use a 4-pint milk bottle or a 1-litre water bottle. Keep in mind: the larger the bottle, the longer your air conditioner is going to last. Don’t freeze a new, unopened bottle of water without drinking some of it first – the water needs room to expand as it freezes. So, don’t fill to the brim, but aim for 75% full.
Once frozen, simply place the bottle in a short tray, to collect excess condensation and run-off. Then cover with a damp cloth (using cold water) and place it directly in front of an electric fan. And voilà: you’ve got yourself a cooling fan, or mini air conditioner.
What happened when I made a DIY air conditioner
I handily had everything I needed for this project. I’d just finished off a plastic bottle of milk (1-litre capacity), which I refilled with water, remembering to leave room for the water to expand. I filled it to about 90% full, thinking that was enough room – turns out it wasn’t. I fitted the lid back on and froze it for 24 hours.
When the time came to remove the bottle from the freezer, it was filled to the brim with ice. The water had expanded to the lid and the bottom of the packaging had even been pushed out by the pressure. Thankfully, it hadn’t cracked the packaging, but this did make standing it upright near impossible.
I worked around this by tucking the edges of the damp cloth (draped over the top) beneath the bottle to keep it steady. I placed it on a tray and moved it in front of the fan, elevating it with a shoebox to give it the best exposure to the breeze. Then I upped the fan speed to increase the effect and closed the window and pushed the door to (the cat absolutely wouldn’t let me close it fully).
I wasn’t sure it was doing anything at first, but the breeze in front of the bottle definitely had a slight chill to it compared with the breeze between it and the fan. I left it to work, and enjoyed lying down in the chilled breeze in the interim.
Within two hours, I could feel the effect – and it was significant. On leaving the bedroom, the hallway felt stuffy and stagnant, whereas the bedroom had a tranquil breeze as the chilled air circulated the room. Only my cat ventured out of here over the next couple of hours, although I decided to dry my hair in another room after a shower, as I didn’t want to ruin the chilly conditions.
My mini air con made the room feel much cooler (and breezier) compared with only having the window open. Plus, there was the bonus that it kept pollen to a minimum. The only problem was it could only last for so long.
I checked it after two hours of running and about 50% of the ice had melted already – that was with the thermostat reading 26 degrees. I noticed at this point that the cloth on top had also dried in that time, despite the condensation on the bottle. So I re-rinsed it with cold water, which refreshed its efforts in front of the fan.
Thirty minutes after that, the room was still cool but the breeze had lost its chill – I could tell the ice was wearing thin. And by three hours, it was just hanging on with the sound of a small lump of ice in the bottle, but as there was still lots of condensation on the outside, I left it to continue to work.
By four hours, the ice had fully melted and finished cooling the breeze. The damp cloth on its own had somewhat of an effect, but it was the icy water bottle that gave it its power.
Stay cool in heatwave - fans
Dyson Purifier Humidify + Cool Formaldehyde
Score: 93/100
This versatile fan kept our testers cool and comfortable with its powerful air flow and 10 different air speeds. Its fastest and strongest setting is noisy, but it has a night mode so you can still enjoy a dreamy sleep. Plus, it also acts as an air purifier and humidifier.
Score: 92/100
This clever design oscillates at up to 130 degrees, so it can cover you and your partner. Though it's a tad bulky, it's extremely quiet, making it perfect for bedtime use. It doubles up as an air purifier, too.
Score: 92/100
This great-value fan, which has 12 air speeds, improved testers' comfort levels. It was relatively quiet and there's a remote control for tinkering with the settings from under the covers.
Verdict
Four hours may not sound like much, but it can make all the difference in this heat. My bedroom felt transformed within this time, so much so that I didn’t want to leave the room! Of course, my makeshift mini air con can’t be compared to a full-size air con and it does come with conditions.
For one, there’s the time limit. This will depend on the size of the bottle and the temperature of the room, but it’s not likely to last through the night based on what can fit in your average freezer. The second issue is the pressure as you freeze your water. The bottle needs a robust plastic exterior to avoid breaking when freezing, although if you have the space, you could freeze your bottle upright with the lid removed to relieve the pressure. Just remember not to fill to the brim, as the water needs to expand.
While I had what I needed at home, this DIY air con wasn’t entirely free to build. There was the energy required to freeze the water, and the energy needed to run my fan (which was upped over the four hours). However, freezers will technically run more efficiently when full (but not overfull), so if you have the space, you could store a few bottles long-term and it would actually save money. What’s more, using the freezer and fan will still be nothing in comparison with the energy needed to run a full-size AC unit.
While it’s a limited quick fix, I can confirm that this method does work when needed. I’m certainly going to make my own DIY air con again over the weekend – it’s only a temporary relief, but it’s inexpensive and effective.
