Types of Chimneys

If you’ve done any research on how a chimney vents then it’s likely you’ve stumbled upon the phrase Class A Chimneys or B-Vent Pipes.  As mentioned above, there are significant differences between systems and the types of pipes used in their construction and/or installation. Understanding the nuances of each chimney type as well as its’ unique parts and purpose is critical to your family’s home safety.

The purpose of a Class A Chimney is to vent high-temperature exhaust from wood-stoves or other appliances such as a furnace or boiler. Class A pipes are used with all types of fuel, and for that reason are often called “All-Fuel Pipes”. Often referred to as Double or Triple Wall Pipes as well as Insulated Chimney Pipes.

B-Vent Chimneys are metal pipes used strictly for gas appliances. Often still used by contractors but is becoming less common. We’ve seen these pipes called many things online. Often b-vents are referred to as “Class B” or “B-Class”, “natural vent” or a “Type-B”.