A UK mother has shared a simple fan trick that could make your home more bearable during a heatwave, and it involves pointing the fan out of the window rather than into the room.
The Correct Way to Use a Fan
Charlotte, who posts on Instagram as @charlotte_family_life, posted a video demonstrating the technique, captioning it: "POV: apparently physics says pointing a fan OUT of the window cools your home down..." She explained that the method is designed to "pull hot air out of your home," allowing the indoor air to become cooler.
"I thought it sounded completely backwards because surely you'd want the fan blowing cool air IN?" she admitted, echoing what most people likely assume. However, after testing it, she said: "The living room feels noticeably cooler than it did an hour ago." She joked in her caption: "Has anyone else tried this, or is it just a heatwave-induced placebo effect?"
Does It Actually Work?
According to Physics Stack Exchange, the trick does work, but only if the air outside is cooler than the air inside. Fans do not actually reduce air temperatures; they move air. By expelling hot air outward, the fan creates a vacuum that draws fresh, cooler air in through other open windows.
Which? explains that for optimal effect, the fan should be placed about two feet (0.6 metres) away from the open window, rather than pressed directly against the screen. This positioning allows the fan to pull more trapped heat from the room.
One commenter shared: "Been doing this for a while now and while it's certainly no AC, it at least makes my room bearable to be in lol. But in those scorching days I just take a cold a** bath."
Another added: "Yes, this works, I've done it before, works great cuz it essentially takes all the hot air in the room and shoves it outside while the other fans take the air from outside and shoves that inside." They noted that the entire window should be sealed around the fan, using a sheet or similar to cover gaps, for maximum efficiency.
Important Considerations
The trick is most effective when the outside air is cooler than inside, even by a few degrees. If the outdoor temperature is higher, the fan may instead draw in hot air, making the room warmer. In such cases, it is better to keep windows closed and use fans to circulate indoor air.
