Expert reveals whether you should open or close your windows during heatwave
Summer is almost here and if you're in the UK, this weekend may already have given you a taste of what is to come.
Temperatures this weekend hit record highs for May and many are probably scrambling for ways to keep cool in the heat.
Thankfully, experts have weighed in on whether you should open or close your windows during peak hours.
Advert
John Small, a UK housebuilder and owner of Ty Eco, says the most common mistake is opening the window every time the temperature rises in the house.
However, he noted: “If it’s cooler inside than outside, you should keep your windows closed.”
Opening them when it is hotter outside draws warm air into your home, making it harder to cool down.
“Heat enters our house in two ways: solar radiation from the Sun, and hot air," Small explained. “We want to limit both, by closing the windows and curtains – but, if it reaches a point where the temperature inside the house is equal to that outside, then you should open the windows, keeping the curtains closed.”
Around late evening through to early morning is the best time to open your windows and let in cool air.
John added: “How it feels, and the actual temperature is deceiving, so always use a cheap temperature probe.”
For those still struggling with the heat, John suggests looking into privacy or reflective window film.
It works by bouncing solar radiation away from the glass rather than letting it pass through. The film lowers the insider temperature while still allowing natural light into the room as well as some added privacy.
Similar practical advice was offered on social media like that of Rahul Joshi (@greatvibesuk_rahul). The Instagram content creator reveals why opening all your windows during a heatwave 'might be the reason your house feels like an oven’.
He points out that most UK homes are designed to retain heat rather than expel it. As such, Joshi advises keeping the windows closed during peak hours (between 11am and 5pm), especially on south-facing windows which receive the most direct sun.
Then, once temperatures drop in the evening, he recommends opening windows on opposite sides of the house to create cross-ventilation and draw in cooler air. Since hot air rises, Joshi described that opening windows upstairs and using a fan can quickly push the hot air out of the house.