For us to fully understand the concept of Cold Air Penetration it is important to wrap our minds around the facts of air being dense.
When the various molecules within air are all squeezed together very tightly the air is more dense or heavier or thicker or heavier. How’s that for a profound scientific explanation? Well, it is true, dense air is heavier and heavy things tend to fall downward.
So, when cold air is outside it tends to fall to the ground. If there is an area around your home where Cold Air can Penetrate it will. Understand that the air inside the house is far less dense than the outside cold air. Less dense air tends to do everything that cold air does but in reverse. Warm air which is less dense has less weight and wants to rise.
- Cold air penetrates the building envelope through all kinds of tiny cracks and crevices of your home.
- As the cold air enters the building its temperature rises, and it quickly loses density causing it to rise
- As the air becomes less dense it increases in size and rises. As the air gets warmer and warmer its size continues to increase
- As the air becomes less dense it rises and forces the inside warm air out. It literally pushes the warm air out
- Many people think that warm air escapes. The truth is that it is forced out by the increased pressure from dense air increasing in size as it warms.
So, Heat Loss is basically Cold Dense Air forcing warm air that is less dense outside.
The trick is to stop the cold air from penetrating.