Why your finished basement may be cold

Articles & Interest

Chances are that your furnace has the capacity to heat your basement and the above-ground levels of your home to the comfort level you expect. So why are so many finished basements cold in winter?

A scientific reason

Physics is one reason. Hot air naturally rises and cold air falls because warm air is less dense. The basement is the lowest point, so that is where the cold air will naturally go. 


A second reason is that the basement is often not insulated as well as the rest of the house. The exterior walls and the basement floor lose heat to the outside (even if the outside is soil). Many basement walls are not completely insulated from top to bottom and very few basement floors are insulated at all. That means there is heat being lost in the basement which will make it cooler.

An Alternate Solution

Since your basement is finished it will be difficult to add more insulation, but there is another solution. Add some cold air return ducting to the basement. For any furnace to deliver warm air to a given room, the cool air that’s already there needs to get out of the way. In the upstairs rooms, the cold air is either removed by the cold air returns on that floor or the cold air naturally moves downwards using the stairway. The basement is the last stop for the cold air so adding a cold air return will help to “pull” more cold air from the basement into the furnace. This makes sure the coolest air is being heated and it also creates space so the warm air can get in.

When basements are unfinished, no one worries much about the comfort level because no one is spending much time there. When basements are finished cold air return ducts are often forgotten. To function properly, they need to draw air from the basement floor level where it’s the coolest. Adding cold air ducting or heating ducts is best done by a professional heating contractor.

If you need professional help making your basement cozy, make sure to hire the smart and safe way with a written contract or service order. All RenoMark members provide a detailed, written contract for all jobs. Click here to find a RenoMark Renovator.