You keep your bedroom coolest during a heatwave by keeping windows and curtains closed during the day, ventilating only after sunset, and using a fan or air cooler in the evening to eliminate the remaining heat. This combination of insulating against the heat during the day and actively cooling in the evening and night is more effective than just opening a window, especially in a well-insulated bedroom where heat tends to linger.
Why does a bedroom get so hot during a heatwave?
During the day, sunlight through the window heats up the walls, furniture, and bed, and they slowly release that stored heat in the evening, even when the outside temperature has already dropped. Windows left open all day actually let more hot outside air in rather than providing cooling. Furthermore, a bedroom on a higher floor, under a roof, or with a lot of window surface area often retains heat longer than a room downstairs or on the north side of the house.
During the day: insulate instead of ventilate
Keep curtains, shutters, or blinds closed during the day on the side where the sun is shining, especially between midday and late afternoon. This prevents the room from heating up like a greenhouse. Only open windows once the outside temperature drops below the inside temperature, usually in the evening or at night, and ensure airflow by opening a window on the other side of the house at the same time.
Evening and night: active cooling
As soon as the evening air is cooler than the room, a fan such as the Tower Fan TV26G helps to actively draw in or distribute that fresher air. Place the fan in front of the open window to blow cool air inside, or let it run in the room to help the sweat on your skin evaporate faster, which provides a noticeable cooling effect without the air temperature itself necessarily dropping. If you want to really lower the air temperature, an air cooler such as the Air Cooler SM211 is an intermediate solution between a fan and a full-fledged air conditioner: it cools the air through water evaporation, without the high purchase and installation costs of air conditioning.
Quick answer: keep your bedroom dark and closed during the day to prevent heating, and only ventilate and actively cool from the evening onwards using a fan or air cooler. This combination works better than leaving windows open all day.
Extra tips for a cooler night
Choose thin, breathable bedding and sleepwear instead of thick fabrics that retain heat. Turn off electronics like a television or laptop in the evening instead of leaving them on standby, as those devices also emit heat. A damp towel on your neck or a hot water bottle filled with cold water at your feet can provide just that little bit of extra relief during the hottest nights until the room has cooled down sufficiently.
Fan, air cooler or air conditioner: what suits a bedroom heatwave?
A fan is the cheapest and fastest solution and works excellently as long as the air temperature itself is not extremely high. An air cooler adds evaporative cooling to that and works best in a dry, well-ventilated room. An air conditioner cools the air most effectively, but requires a larger investment and considerably more power. For most bedrooms during a Dutch heatwave, the combination of good insulation during the day with a fan or air cooler at night is sufficient for significantly better sleep comfort.
| Solution | Cooling effect | Power consumption indication |
|---|---|---|
| Fan (TV26G) | Cools through airflow, not the temperature itself | 30 - 65 watts |
| Air Cooler (SM211) | Also lowers the air temperature via evaporation | ±65 - 100 watts |
| Air conditioner | Cools the air most effectively | 800 - 2000 watts |
Want to be well-prepared for the next heatwave? Check out the Air Cooler SM211 or the full range in the air conditioner and fan collection.
Frequently asked questions
Should I leave the window open or closed at night during a heatwave?
Open, as soon as the outside temperature has dropped below the inside temperature. Ensure airflow by opening a window or door elsewhere in the house as well.
Does a fan really help during a heatwave?
Yes, although a fan does not lower the air temperature, it accelerates the evaporation of sweat on your skin, which makes your body noticeably cooler.
Is an air cooler a good alternative to air conditioning?
For most bedrooms, yes: an air cooler is quieter, cheaper to purchase, and consumes less power, although the cooling effect is less powerful than that of a real air conditioner.
Why does my bedroom stay so warm in the evening even though it has cooled down outside?
Walls, furniture, and the bed have stored the day's heat and release it slowly, even after the outside temperature has already dropped.
Does sun protection really help against overheating the bedroom?
Certainly, exterior blinds or closed curtains during the day prevent sunlight from heating the room like a greenhouse, which makes a significant difference to the evening temperature.
Can I use a fan and an air cooler at the same time?
Yes, that works perfectly. An air cooler that sends moist, cooler air into the room, combined with a fan that further distributes the airflow, enhances the cooling effect.