Mastering airflow in your home to beat the heat and stay mould-free

We’ve had some warm weather recently, which means keeping our homes cool has been a challenge on some days.

However, did you know that opening your windows strategically can be a simple yet effective way to not only achieve a comfortable temperature in your home, but also help to prevent damp and mould growth?

Well it can, and here’s how.

The stack effect

Imagine your home as a chimney. Warm air naturally rises. But by opening windows on opposite sides of your house, you create a stack effect: cooler air is drawn in through the lower windows, pushing warm air out through the higher ones.

This circulation keeps your home feeling fresh and prevents heat from building up.

Here's how to do it

Identify the breeze: Feel which direction the wind is coming from. Ideally, you want windows on opposite sides of the house facing the wind.
Open up high and low : On the side of your house catching the breeze, open windows on the lower floors (around knee height works well). On the opposite side, open windows on the higher floors (near the ceiling). This creates the strongest air flow.
Maximize the flow: Open windows as wide as possible for maximum air circulation. If you have trickle vents, keep them open throughout the day for a constant flow of fresh air.

If you live in a flat, you can create cross ventilation by opening windows and doors at the opposite ends of your home. If you have a clear path for the air to flow (e.g. no large pieces of furniture in the way to slow it down), this will increase its effectiveness. Use a fan to enhance breeze. This BBC article has more details.

Fresh air, happier home

By promoting healthy air circulation, you're not just keeping cool, you're also preventing damp and mould growth.

Mould thrives in stagnant, humid environments. Proper ventilation helps remove moisture from the air, creating a healthier living space for you and your family.

To support airflow:

Close windows and curtains during the hottest part of the day to keep the sun's heat out.
Open windows for short periods during the day, e.g. in the very early morning when it is cool and in the evening hours once the sun goes down.
Consider using fans to further circulate cool air within your home.
Checking that any heating and lights are off, and unplug electrical items not in use, such as washing machines as they can generate heat.
If you can, use your boiler on a lower temperature for part of the day as hot water storage can cause your home to heat up.
Limit hot activities such as using an oven or cooker and stick to cold food such as salads and sandwiches during the hottest part of the day.

More advice

Habinteg is committed to helping you live comfortably in your home. For more simple information on ways to keep your house cool in summer, take a look at these videos:

Should you open your windows on a hot day:
https://www.youtube.com/watch?v=9QRw4dUo38g

Best fan placement in a house:
https://www.youtube.com/watch?v=YUOQad6esE4

How to keep your house cool in summer without air conditioning:
https://www.youtube.com/watch?v=4BLfYtE4Kow