Why Sizing Your Liner is Important

Making sure that you have the right size liner is very important. The ideal size for a liner will depend on what type of appliance it is being hooked up to. Generally, for woodstoves, wood furnaces, and wood inserts, it will be the same diameter as the exhaust collar of your appliance. You NEVER want to use a liner that is smaller than the exhaust pipe of your appliance.

Size is one of the most important aspects to having a well functioning chimney pipe. You need to be able to fit your liner down the chimney as well as be able to match the exhaust size of your appliance. If your liner is too small, it might not allow the necessary exhaust volume that is needed for efficient operation. If the liner is too big, it may draft too slowly and develop too much updraft when it heats up.

Making sure that you measure the inside diameter of your chimney is equally important. You will need at LEAST a 1 inch space for the inside dimension bigger than the size of the reline pipe you plan on using. It’s important that the chimney maintains that clearance all the way down to where you will come out to the appliance with the liner. The more clearance between your chimney and the liner the better – more insulation can be used to fill the space.

If you are planning on lining your fireplace chimney, then you will want to measure from the top of your chimney to the top of the smoke chamber to figure out the length that is needed. To determine the length of liner needed for a wood stove, you will need to measure from the top of the chimney to where you will be connecting your stove.

When looking to size a liner for an oil appliance, you will need to determine the GPH (gallons per hour) of the unit. If you are using a gas appliance you will need to determine the max BTU input of your appliance to help determine the size liner you need.

The advantages of having a properly sized chimney liner are improved draft, hotter core temperatures, easier cleaning, improved safety, and longevity, keeping your chimney safe for many years to come.