Stack effect

Hey kiddo, have you ever played with a tower of blocks? When you stack the blocks on top of each other the tower becomes taller and taller, right? Something similar happens with air when it is trapped inside buildings.

When you are inside a building, the air outside and inside are usually different temperatures. If the air inside is warm and the air outside is cool, the warm air rises up and tries to escape through any openings it can find - this creates what we call a "stack effect".

Think of it like a chimney. When you light up fire inside a chimney, the hot smoke rises up and exits through the top. This is because it's lighter than the cold air outside. In a building, the stack effect works in the same way, except there is no fire.

Warm air rises and escapes through small openings like cracks and vents on the top floors while the cooler air rushes in to replace it from the bottom. This cycle keeps repeating itself creating a kind of air flow.

This process is necessary as it helps keep the inside air fresh and reduces humidity, but it can also have an impact on the temperature of the building. For instance, in winter the warm air escapes, and the cold air enters, making the building colder. The opposite happens in summer, and it becomes hotter.

So just like with your tower of blocks, the more floors a building has, the taller the stack effect becomes, and the stronger the air flow will be.