Advice
How to cool a bedroom during a heatwave
Practical steps for keeping a UK bedroom cool overnight during a heatwave, including when portable air conditioning helps.
Stop the heat getting in
Close curtains or blinds on sun-facing windows during the day, and keep internal doors shut so you are only cooling one room rather than the whole house.
Open up in the evening once the outside temperature drops below the inside temperature, not before.
When a portable unit makes sense
UK homes are built to retain heat. In an extended hot spell, a bedroom that has absorbed heat all day will not cool down overnight through ventilation alone.
A portable air conditioner removes heat rather than moving it around, and vents it outside through a window kit. That is the difference between a fan and air conditioning.