Many people’s first response to rising temperatures is to open all their windows to ‘let some air in’.
But this isn’t always the wisest idea - and could even cause the temperatures inside to soar.
Here’s when you should open and close your windows – and some other advice on how to keep the heat out of your home.
When should I open my windows?
Most people think that leaving windows open on hot days will help cool the house - but this isn’t true in all cases.
In hotter countries it’s common practice to block the sun out completely during the day, and there’s a very good reason they insist on keeping their windows closed.
It comes down to a couple of key elements, namely how much natural air circulation there is in your home experiences and how well your home is insulated.
If there isn’t a decent breeze outside, having your windows open for a long period can increase the temperature in your home rather than reduce it.
Meanwhile, while we think of insulation as being for keeping heat in, it actually slows the transfer of all heat – meaning it can also keep heat out.
This is also the case for double glazing, so opening those windows can just mean inviting heat in that would otherwise be kept out.
First thing in the morning, check to see if it’s cooler outside than in. If it is then open your windows to encourage fresh air to flow through the house.
Keep an eye on the temperature and, as soon as it starts to rise, close all your windows to keep cool, beofre opening them again if it cools in the evening.
Whenever it’s warmer outside than it is in your home it’s better to keep your windows closed – that’s doubly the case should you be lucky enough to have air conditioning.
Keeping internal doors open can also help to circulate the air throughout your home with less risk of increasing the temperature.
Remember to keep your home secure
While we’re keen to keep our homes cool it’s also important to remember to keep them secure.
It may be tempting to leave windows open in the cooler evenings when you go out, but this is never a good idea.
Stick to opening windows while you are at home – unless you can guarantee they can’t be exploited by potential intruders.
Keep curtains and blinds closed
Try to get into the habit of closing your curtains and blinds during the day when the sun is at its hottest. If windows in certain rooms catch a lot of direct sunlight, use dark or blackout curtains or blinds to prevent the rays from overheating your room.
If you’re handy with DIY, you could also opt for bubble wrap insulation which will help to temporarily block out the sunlight, increasing your windows insulating properties by creating a layer of still, trapped air.
Using shades or reflective material such at tinfoil outside the windows can also help to keep cool inside.
External window shading
Another good tactic is to create shade outside of your windows, especially in your living room if you sit in there during the day. If you love gardening, planting trees or high plants outside of the windows helps create shade and keep the space directly outside of the area cooler. When plants lose water vapour, they often cool the air around them.