Chimney Flues Size

For example a 13 x13 flue can be wrapped with eight standard brick per course to build a chimney that is 21 x21.

Chimney flues size.

Required chimney area can be calculated as. If a chimney s diameter is six inches then the flue should also measure six inches. If the flue is circular then it should be at least one tenth the size of the fireplace opening. The ideal flue size is typically determined by the exhaust outlet of the stove or appliance.

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. Just muliplying these dimensions together 6 75 x 6 75 45 56 sq in. A 6 inch stove requires a 6 inch flue. However generally speaking a rectangular chimney flue size should be at least one eight of the fireplace s opening.

For example an 8 x 8 square nominal clay chimney flue tile liner has inside dimensions of 6 3 4 x 6 3 4. As i said standard flues were designed to fit with standard brick. Quality chimney liner material that meets astm and excels in freeze thaw environments. The velocity of air and flue gas in a smaller furnace should not exceed 2 m s.

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. Dimensions for square rectangular and round clay flue liner. Design velocities of larger furnaces should not exceed 10 m s. Flues should also mirror the size of a chimney.

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. A standard 12 x12 flue was what we now call a 13 x13 flue. A cross sectional area of chimney m 2 q volume of flue gases at chimney temperature m 3 s v velocity m s. Solving your chimney s math figuring out the proper size for your chimney flue can seem like a challenge.

Please note that the chimney pot base should not impinge upon the inside surface of the flue liner. A modular 12 x12 flue is what we now just call a 12 x12 flue. In most cases a step up is also fine. As a general rule the diameter of the chimney should match the flue collar on your wood stove.

In the end you just want a chimney that drafts properly and allows you to enjoy your fireplace. A q v 3 where.