Chimneys and Fireplace Sizing
Chimneys and fireplaces for stoves burning wood or coal as fuel.
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
Boiler house topics, fuels like oil, gas, coal, wood - chimneys, safety valves, tanks - combustion efficiency.
• Heating
Heating systems - capacity 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.
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.
