Chimney Flue Dimensions

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.

Chimney flue dimensions.

For example you could vent a 6 inch stove into an insulated chimney that is 8 inches in diameter. Superior clay manufactures a complete line of vitrified clay flue liners from 3 to 36 diameters in round flue liners and from 4 x8 to 24 x24 in square and rectangular flue liners. Terra cotta flue intent is to contain the combustion products and direct them to the outside atmosphere. Chimney vent capacity chart btu h and kw pdf.

Typical standards require a cross section area of the fireplace flue or chimney vent to be equal to 1 10 of the area of the fireplace opening itself for a conventional wood burning installation and without considering the effects of a glass fire door. The outer wall of your pipe also needs to be covered by your cap but it doesn t matter if your cap extends beyond the edges of your pipe. A q v 3 where. The ideal flue size is typically determined by the exhaust outlet of the stove or appliance.

50 mm of noncombustible material brick and 3 4 in. 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. Check with your local code enforcement officer or fire dept for proper installation. Click to enlarge any image.

350 mm consisting of the same elements. Quality chimney liner material that meets astm and excels in freeze thaw environments. Socket type joints and self aligning joints are available in round flue liners. A 6 inch stove requires a 6 inch flue.

100 mm bearing length brick. Just muliplying these dimensions together 6 75 x 6 75 45 56 sq in. Thickness of a lined chimney to be used as a structural component is 10 in. A pipe with a seven inch inner diameter for example requires a seven inch chimney cap.

The diameter of the chimney cap you choose needs to be the same as your pipe s inner diameter. 250 mm consisting of. As a general rule the diameter of the chimney should match the flue collar on your wood stove. Chimney vent capacity chart btu h and kw.

In most cases a step up is also fine. A cross sectional area of chimney m 2 q volume of flue gases at chimney temperature m 3 s v velocity m s in general 1 kw boiler heat requires 1100 mm 2 of chimney area. An unlined chimney s minimum wall thickness is 14 in. They help protect the chimney walls from heat and minimize condensation.

Required chimney area can be calculated as.