Skip to content

What's the difference between a gas fireplace and a gas fireplace insert?

Gas fireplace, gas fireplace insert, is there really a difference? 

Yes! Terms in the fireplace industry can be a bit confusing, let's straighten this one out. 

A gas fireplace can also be know as a direct vent gas fireplace or zero clearance gas fireplace.  Direct vent refers to the style of venting, we have an article about that too if you're interested.  Zero clearance refers to the clearances to combustible materials.  Side note, not all gas fireplaces are truly zero clearance fireplaces, many require non-combustible facing material around the sides and top, some even require non-combustible framing (steel studs) above the fireplace.  For this article, we'll stick with gas fireplace.  

A gas fireplace insert can also be known as a direct vent gas fireplace insert or just gas insert.  Again, the direct vent refers to the style of venting (has an air intake and exhaust).  For this article, let's use gas insert to make it a little easier.  

The details...gas fireplaces

A gas fireplace is typically installed in a wall with standard wood framing surrounding it.  A gas fireplace is generally larger and has additional insulation or air space around the firebox so that the outside of it stays cooler and hence can be surrounded by combustible material. 

A little about venting

This type of fireplace uses a coaxial direct vent system.  This means that the vent pipe is a pipe within a pipe.  A common system includes a 5" inner exhaust pipe surrounded by an 8" outer pipe.  The space between the two allows for the air intake.  This type of vent pipe can be installed inside a wall or wooden chase.  There are clearance requirements to combustible materials (e.g. wood studs or drywall).  Typically, if the vent is running vertically, you need a minimum of 1" clearance all the way around the pipe.  If the pipe is running horizontally, you need a minimum of 3" clearance from the top of the pipe and 1" clearance from the sides and bottom of the pipe.  These vent systems can be run up through a roof with a vertical termination or out through an exterior wall with a horizontal termination.  For a detailed explanation of the type of fireplace, check out our previous post about direct vent fireplaces. 

And now...gas inserts

A gas insert is installed within an existing masonry, wood burning fireplace.  A gas insert is smaller than a gas fireplace to allow it to fit inside of the opening of an existing wood burning fireplace.  These fireplaces have fireboxes that are just about as big as the unit itself with little to no insulation or air space.  A gas insert can get much hotter on the outside (no, not that hot) than a gas fireplace.  This is okay because a gas insert is within a non-combustible space (masonry fireplace) that can take the heat without any danger.  

A little more about venting

A gas insert uses co-linear venting.  A standard gas insert has two 3" flexible liners that are dropped down the masonry chimney and connected to the insert.  One liner acts as the exhaust and the other acts as the air intake.  At the top of the chimney they are connected to a cap that keeps them separated.  Here's the best drawing I could find for this, not great, but I think it should give you the idea. 

Gas Fireplace Insert


What have we learned? 

Hopefully a little about these two types of fireplaces, if not that's okay.  In short, if you are building a new house or remodeling, you typically want to look at gas fireplaces.  If you have an existing masonry/brick/stone, wood burning fireplace with a chimney, you want to look at a gas insert.  

We know this stuff can be confusing, we're here to help! Don't hesitate to reach out to our experts with any questions you may have. 

Thanks for reading, feel free to leave any questions in the comments, but for a faster answer, email or call us 844-635-5499.


Next article The 10 Best Electric Fireplaces of 2019 | Online Buyers Guide

Leave a comment

Comments must be approved before appearing

* Required fields