Hot Air Rises
This is the law of nature that makes the upper floors of a house generally warmer than the bottom floor or basement. It’s called convection, and it’s responsible for much of the heat and cold lost inside our homes. In the winter, you heat the inside of your house, and that heat is constantly trying to escape through convection and other means. It heads right upstairs and sneaks through all the little holes in your ceiling between the top floor and the attic and from there makes its way outside.
As the warm air is leaving the house, it’s also pulling outdoor air into the house through tiny gaps around doors and windows, cracks in the foundation, around pipes entering the house, etc. This cool “makeup” air just makes your furnace work harder to keep you comfortable. In the summer, the same effect leads to inefficiency with air conditioning, because convection is pulling hot outdoor air into the house, making your air conditioner work harder.
Now that we’re done with the science lesson, let’s look at what home energy experts say about cooling your house more efficiently.