As the UK experiences record-breaking temperatures above 40°C, a debate has emerged on the best way to keep homes cool. Dr Andrew Shea, a senior lecturer in building physics at the University of Bath, advises keeping windows closed if it is cooler inside than outside. Opening windows can let in warm air, making the home even hotter.
Dr Ana Souto, a principal lecturer at Nottingham Trent University, recommends closing everything and only opening windows late in the evening and early in the morning, until around 9am. She describes her own home as 'like a cave' but says it works effectively.
Professor Amin Al-Habaibeh suggests exceptions: if indoor and outdoor temperatures are equal, windows should be opened but with curtains closed. South-facing windows may need opening to prevent a greenhouse effect. Conservatory windows should always be open during a heatwave, with the door to the house closed.
Regarding the use of wet towels in front of windows, Dr Shea is sceptical, stating the cooling effect is insufficient in extreme conditions. He concludes that keeping warm air out altogether is the best strategy.
