Chimney Flues Size

Quality chimney liner material that meets astm and excels in freeze thaw environments.

Chimney flues size.

The rule of thumb for sizing a chimney liner is that you never want it to be smaller than the appliance exhaust hole and you don t want the liner to be three times the area of the exhaust hole of the appliance. For example a 13 x13 flue can be wrapped with eight standard brick per course to build a chimney that is 21 x21. The velocity of air and flue gas in a smaller furnace should not exceed 2 m s. If the flue is circular then it should be at least one tenth the size of the fireplace opening.

Please note that the chimney pot base should not impinge upon the inside surface of the flue liner. As i said standard flues were designed to fit with standard brick. A 6 inch stove requires a 6 inch flue. A standard 12 x12 flue was what we now call a 13 x13 flue.

In most cases a step up is also fine. For example you could vent a 6 inch stove into an insulated chimney that is 8 inches in diameter. In the end you just want a chimney that drafts properly and allows you to enjoy your fireplace. A cross sectional area of chimney m 2 q volume of flue gases at chimney temperature m 3 s v velocity m s.

Dimensions for square rectangular and round clay flue liner. As a general rule the diameter of the chimney should match the flue collar on your wood stove. Square flue liners are nominally sized using outside dimensions. Solving your chimney s math figuring out the proper size for your chimney flue can seem like a challenge.

If a chimney s diameter is six inches then the flue should also measure six inches. However generally speaking a rectangular chimney flue size should be at least one eight of the fireplace s opening. One exception to this is that round based pots may impinge at the corners of a square flue but not by more than 3 4 in. With that in mind the height of the chimney should be at least 15 feet from the floor of the fireplace to the top of the flue.

Flues should also mirror the size of a chimney. Design velocities of larger furnaces should not exceed 10 m s. For example an 8 x 8 square nominal clay chimney flue tile liner has inside dimensions of 6 3 4 x 6 3 4. But chimney experts and draft measurements show that in a rectangular flue not all of the cross sectional area is equally effective in developing draft.

A q v 3 where. A modular 12 x12 flue is what we now just call a 12 x12 flue.