Venting for Fireplace Inserts: How to Make the Right Selection

Did you know there are different types of venting for different fireplace inserts? There are six main ones to discuss. Those are direct vent co-linear, direct vent co-axial, b-vent, vent free, wood vent, and pellet vent. So, let's discuss each vent type and what it means for your fireplace insert selection.

• Direct Vent Co-Linear: Direct vent systems feature dedicated intake and exhaust venting. Co-linear vents are completely separate lengths of pipe for intake and exhaust. Generally reserved for inserts, co-linear vents tend to be smaller in diameter than coaxials and are run side-by-side through existing chimney systems.

• Direct Vent Co-Axial: On the other hand, co-axial venting systems are concentric in design and feature a pipe-within-a-pipe design. Each section of pipe or length of flex is complete with the smaller exhaust vent securely routed down the center of the larger intake vent. This makes for an easier installation and has the added benefit of using the outer intake pipe as insulation for the exhaust vent.

• B-Vent: Another type of venting is called B-vent or natural venting. The components are double-walled and rely on indoor air for combustion, using negative pressure to draw air into the fireplace insert. Due to this, they cannot be vented horizontally. B-vent is becoming less common but is still favored by contractors and builders.
• Vent-Free: Vent-free fireplace inserts don't require venting. They are easier to install than their vented counterparts and offer more flexibility in where they can be installed. When a vent-free fireplace insert is installed, the chimney of the existing fireplace is closed off.

• Wood Vent: Wood venting is designed for use with wood-burning fireplace inserts. Manufacturer instructions will dictate when specific wood venting is required. The venting can be single or double-walled and generally terminates vertically.

• Pellet Vent: Similarly to wood venting, pellet venting is designed for a specific fuel type. Its venting will also be specified in the manufacturer's instructions. Pellet vents are double-walled and airtight. They also typically feature a galvanized steel outer wall and can terminate vertically or horizontally.

Venting can be difficult to understand, but hopefully, now you understand the differences between the types and know which will be best for your new fireplace insert. Now, let's move on to the next selection needed in the fireplace insert process—style!