In our last post, we covered what a combustion air vent is, so in this entry, we’ll cover problems which may come up during your basement remodel or afterwards. The most common, but easily remedied, problem is blockage.
Intentional
The cold air that the duct brings in over the winter tends to make the floor very cold, so some people either stuff rags in the duct or block the outer entrance for the sake of a warmer home. In reality, this has the opposite effect, since a blocked combustion air vent encourages leaks elsewhere. Simply remove the blockage to solve the problem.
As for the cold floor problem, you can install a tube at the end of the duct in the basement and bend it into a “J” shape. The air is forced to rise which warms it in the process and keeps it off the floor.
Another way to fix it is to put either a box or bucket under the vent, but make sure that the bucket is at least twice the diameter of the vent. If it’s too small, air won’t be able to circulate, which means the duct will still be blocked.
Poor Maintenance
Because air is drawn in through the duct, everything in the air comes with it, and the intake becomes clogged. Checking and clearing the vent at least once a year, but if you do it in the summer or fall, watch out for wasp nests. They like sheltered, quiet spots like the vent.
Small Mesh
Outer openings must be covered with protective mesh with openings no smaller than ¼” and no larger than ½”. If the screen is the problem, remove it and replace it with a ¼” hardware cloth.
Unintentional
When new siding is being put on the house, sometimes the crew loses track of which hole is for which purpose, and a damper gets installed instead of a screen. Solve this by removing the damper and replacing it with a screen.
Once your combustion air vent is unclogged, you can expect to see lower energy bills, and fewer leaks cropping up after you mend the ones you may already have.
