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(Illustrative Photo: users.design) |
It is often noticed that there is a breeze coming from completely closed windows, with not even the slightest gap. This may seem very strange at first. However, it is actually quite normal. Simple physics will help you understand this phenomenon.
The air in a room is almost never completely still. There are often invisible air currents generated by changes in temperature. Warm air expands and becomes lighter, while cold air contracts and becomes denser. The lighter, warm air near a heater is pushed upwards to the ceiling, while the relatively heavier cold air near windows or cold walls sinks down towards the floor.
Using a balloon, we can easily detect these air currents. It’s important to tie a small weight to the balloon so that it doesn’t just stick to the ceiling but can float freely in the air. Bring it close to a roaring fire and then release it; it will be carried by the invisible air currents on a little “journey” around the room, rising from the fire to the ceiling, out the window, then descending to the floor, and back to the fire to continue its exploration of the room.
That’s why we feel a breeze coming from the windows, especially near the floor, even when they are tightly closed.
