Venting is required to remove harmful combustion gasses from the firebox and expel them outside. When installing a gas fireplace, you have the option to use a B-Vent, direct venting or using a vertical collinear vent.


If you’re using your existing wood-burning fireplace for a new gas fireplace, you might choose to use an approved metal liner that includes a B-vent.  While installing a B-Vent is easy and affordable, you could lose some efficiency.

Direct vent fireplaces are popular because it’s a flexible and efficient means of removing combustion products. 

This sealed venting system runs through an outside wall horizontally or through the roof vertically. 

The two-part system uses one pipe to bring combustion air in and one pipe to remove combustion products.

The most popular option for an insert is a double liner up the chimney. By drawing combustion air from the top of the chimney, there is much better efficiency than using a B-vent.

There are also some gas fireplaces that utilize power venting, which is a fan that helps improve the venting process. While not common, power venting can drastically improve a fireplace’s efficiency. One thing to note is that power venting is reliant on electric power, so it will not work in the event of a power outage unless there is a generator to provide auxiliary power. 

If you have any additional questions about fireplace venting,
don’t hesitate to contact one of our experts at Harding The Fireplace.