Chimneys and Fireplace Sizing
Chimneys can be separated in two main categories:
- metal
- masonry
Prefab or Metal Chimneys
Prefab or metal chimneys, class A and double or triple walls are usually found in three diameters. Each diameter has a specific usable area, which is also called it's cross section.
The capacity of a chimney to remove smoke and/or energy (BTU's) from an appliance is directly related to the cross section area.
Chimney Size | Common Venting Uses | |
---|---|---|
Inside diameter (inches) | Inside Area (square inches) | |
6 | 28.3 | Stoves, Central Heaters |
7 | 38.5 | Stoves, Central Heaters |
8 | 50.3 | Stoves, Small Fireplaces, Central Heaters |
10 | 78.6 | Stoves, Fireplaces, Central Heaters |
12 | 113 | Fireplaces, Central Heaters |
Masonry Flues
Flue Size | Common Venting Uses | |
---|---|---|
Outside Diameter (inches) | Inside Area (square inches) | |
7 1/2 X 7 1/2 | 31 | Stoves, Central Heaters |
8 1/2 x 8 1/2 | 41 | Stoves, Central Heaters |
8 1/2 X 13 | 70 | Stoves, Fireplaces, Central Heaters |
13 X 13 | 99 | Fireplaces |
13 X 18 | 156 | Fireplaces |
Related Topics
• Combustion
Combustion processes and their efficiency. Boiler house and chimney topics. Properties of fuels like oil, gas, coal and wood and more. Safety valves and tanks.
• Heating Systems
Design of heating systems - capacities and design of boilers, pipelines, heat exchangers, expansion systems and more.
Related Documents
Chimney Sizing
Calculate chimney draft and required chimney area - online calculator.
Chimney's Explosion Doors
Recommended size of explosion doors or draught stabilizers in oil fired installations.
Chimney's Size vs. Boiler Power
The size of chimney vs. boiler's heat load.
Chimneys - Roof Termination
Chimneys and single wall vents roof termination.
Fuel Oil Burners
Pot types, gun types and rotary types fuel burners.
Natural Draft - Air Flow Volume and Velocity
Air flow - volume and velocity - due to stack or flue effect caused by indoor hot and outdoor cold temperature difference.