How To Install A Combustion Air Vent

Last week, I wrote about what gas pipes are and why homes need them. This week, I’ll track down some of the most common problems and solutions related to gas duct installation and maintenance. When the gas duct is blocked, the air needs to ‘enter’ into the house through various unwanted routes. I have done several home inspections where the windows completely freeze in the house and in all cases there was a clogged gas line.

Problem: Deliberate blockage, lack of understanding

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A gas pipe brings in fresh outdoor air, which usually means cold Minnesota outdoor air. This can create a cold floor where the ductwork ends, as well as a cold draft. I was going to do a nice little drawing of cold air entering the basement around my own gas duct, but then I remembered I had an IR camera. Of course. Take a look at the two images below for a good look at how the gas pipes made my basement floor cold. To prevent cold air from entering the house, people sometimes stuff clothes or towels into the gas duct, or block the air inlet on the outside of the house. Solution: Remove any obstructions. If you want to help cut down on the cold air that just spills into the basement, try creating a trap at the bottom of the gas duct. Make the air have to rise again before entering the house. I don’t have any hard evidence that this makes a big difference, but I convinced myself it would help and it was easy enough to do. The two most common ways to create traps are to make a “J” at the bottom of the conduit, or place a bucket or box underneath the conduit. With either method, the air will need to rise before entering the house.Just make sure that the bucket or box you use isn’t too small to restrict airflow. I keep this in mind all the time, but if you’re super good, you can make your sixth grade math a success by measuring the inside diameter of the bucket and the outside diameter of the pipe, then then calculate the surface area (?R) and make sure that the bucket is at least twice the size of the conduit.Also, make sure that the duct is not so long that the opening lies flat on the floor, effectively blocking it.

Problem: Lack of maintenance

Opening the outside of the gas duct brings air into the home and brings in dust, dirt, insects, leaves, etc. I’ve noticed that the closer the gas line is to the ground, the more likely it is to get clogged. clogged with debris.Solution: Every year look under your gas pipe to make sure it’s clean. If you do this in the summer or fall, watch out for wasps. They love to nest during this opening period. If the opening is dirty, vacuum it up. If you have HRV, check your HRV intake at once.

Problem: Small mesh on the outside

Doors to the outside of the house should be covered with wire mesh with holes not less than 1/4″ and not more than 1/2″. When a standard window screen is used here, it gets dirty very quickly. Click on the photo below for a larger view; you will see the actual opening is covered by a window screen, which will be removed.Solution: Remove any mesh or restraining material and replace it with a 1/4-inch stiff cloth or similar material if not already present.

Problem: Inadvertent blockage, lack of understanding

Frequently, vinyl baffle installers will forget which opening is for the combustion air intake and they will install a damper in this hole instead of a shield. These dampers allow air to go out, not in.Solution: Replace the external terminal with one designed for gas intake, or remove the damper and cover the opening with a 1/4″ hard cloth.

Problem: Input is installed too close to ground

Read more: how to take a screenshot on galaxy note 5 The inlet for the gas pipe needs to be installed at least 12 inches or more. When it is too close to the ground, it can get dirty very quickly and can be covered with snow.Solution: When the gas inlet is installed close to the ground, it is usually done because that is where the rim brace is located, so creating a higher hole in the side of the house is not an option. The solution was to install what Milind calls a ‘snorkel’. I burst out laughing when I heard this for the first time, but I love the term. I think the photo below is pretty clear.That concludes my list of the most common installation and maintenance errors with gas pipes. If I think of any more, I’ll add them to this list in the future.Related articles: