Convection is really important when we think about how heat escapes from our homes. It’s also something to keep in mind when we’re designing insulation.

So, what is convection?

In simple words, convection is how heat moves through fluids, like air or water. When some parts of a fluid get warm, they rise, and the cooler parts sink down. This creates a cycle of movement, and it can cause heat to leave buildings.

How Convection Causes Heat Loss:

1. Air Movement: When the air inside a room gets warm, it starts to rise. As it does, it can create a draft by moving toward cooler spots. Often, this warm air escapes through little gaps or openings.

2. Insulation Gaps: If insulation isn’t put in properly or has holes, warm air can sneak out, and cold air can come in. This means the insulation isn’t doing its job.

What to Think About When Designing Insulation:

To reduce heat loss from convection, insulation materials should:

• Be Thick: Thicker materials can slow down the air movement, which helps keep warm air inside.
• Have Air Pockets: Making materials with spaces that trap air can stop air from moving around. For example, polystyrene has these air pockets.

A Simple Example:

Think about a wall. If it has fluffy fiberglass insulation, the air gets trapped inside. This stops warm air from going through the wall and escaping. But if a wall doesn't have any insulation, - the warm air rises, and cold air comes in, which can lead to higher heating bills.

In short, good insulation must fight against convection to save energy and keep buildings warm.