Do You Need a Chimney for a Gas Fireplace?

That’s a good question and one that is often asked in the context of gas stoves and gas log sets too.

We know that the traditional style of lighting a fire in the house using a wood-burning fireplace absolutely needs a chimney. But things work a little differently with all gas appliances, right? So, why not fireplaces? That’s a valid question.

The demand for gas fireplaces has been on the rise ever since their installation became easy. One of the reasons for that ease is because, with these appliances, there is no actual combustion which makes zero-clearance installation a possibility. That means you can actually install a gas fireplace in contact with walls and floors that are combustible. They are constructed such that heat insulation is maximum. But, about ventilation now. Well, you’ll need some of it, won’t you? 

Do you need a chimney for a gas fireplace?

It depends!

There are 3 primary types of ventilation for gas fireplaces dependant on the model you choose. 2 of those need chimneys of some sort and the other does not, it’s completely vent free (often called a ventless fireplace).

Keep reading for a more in-depth explanation below.

Gas fireplace

Types of Ventilation for Gas Fireplaces

Primarily, there are three different options to ventilate a gas fireplace.

- B Vent

This is also referred to as a natural vent and it uses a masonry chimney or you could go for a factory-built metal one. The idea is to use an existing chimney for ventilation purposes. There is a single pipe or a flexible liner inside the chimney which uses the air inside the room to flush out the byproducts of combustion.

- Direct Vent

This is a system wherein the outside air is drawn in for combustion. The spent air is sucked outside through a co-linear venting system. Using a direct vent, you can reduce the loss of heat that is typical of traditional chimneys. You can use this to flush out the spent air into the back of your house or through the roof. If there is an existing chimney, there is no need to get rid of it. Instead, just make sure the vent unit has a sealed door, preferably made of glass, so that the indoor air quality is not compromised.

- Vent-free (also known as ventless)

The third solution, and probably the best, is to go vent-free. There was a time when this was not preferred at all and was even a bit controversial. But today, fireplaces that use catalytic-converter technology are in great demand.

These units work like exhaust systems on some of the newer car models. There is a combustion chamber from which the hot air exits. And it goes through a bit of a purification process before leaving the chamber so as to not compromise the air quality of the room. And they look great too. Sleek like a plasma television set.

Thanks to these ventilation systems, you can now install a fireplace inside a wall or under a window. This directly answers the original question. No, you don’t need to install a chimney if you’re getting a gas fireplace. And it gets better because if you’re in a house which already has a chimney, you don’t have to spend money and get rid of it.

And you don’t have to worry about the heat because gas fireplaces are insulated well, usually with a ceramic or tempered glass. They are exposed on three sides creating a peninsula or on four sides like an exposed island.

Do You Need a Chimney Liner for a Gas Fireplace?

If you are opting for a chimney though, there are a few things to take care of. A lot of people neglect to get a chimney liner when installing a fireplace.

Yes. If you have a chimney, you must get a chimney liner. It is not only useful but also proves to be invaluable for safety reasons.

The first step is to check with your municipality because, in some places, your chimney is required to have a liner. If you're not, there are still plenty of reasons to get one.

Without this liner, you will realize pretty quickly that the walls of your chimney are more susceptible to damage. The heat is also sure to cause damage to the bricks and mortar in your fireplace. That is why, even if you’re moving to a new house with a chimney, it is critical to check if it has a liner and if it needs replacing.

It is also a good idea to replace the liner if you find moisture on the walls of the chimney. This applies even when you are switching from a wood-burning fireplace to a gas alternative. Gas fireplaces typically use aluminium liners and wood-based fireplaces work well with steel liners.

And you don’t have to figure this out all by yourself. Get a chimney inspector to take a look. In fact, that is the best approach because installing gas fireplaces is anyway a job for professionals. Considering the risk you run if you do a shoddy job, it’s best to let the pros take over.

The Bottom Line

There are many advantages to having a gas fireplace. To begin with, all you need is a natural gas connection to get going. It can be installed anywhere in the house and you can pick a good-looking unit that fits the decor of the room it is in.

Since actual wood is not involved, ventilation is easy and there is no smoke or particle mess to clean up. You can switch it on and off with a button like a television and you don’t need to worry about storage space. There is also little heat loss which makes it efficient.

But before you jump and place the order, remember that these units run on propane which is expensive compared to wood for the same amount of heat. If you like camping ambience, you won’t get it with a gas fireplace. And a bad installation job is not just something to fix. It is actually a hazard to you and those who are sharing the house with you.

Almost every product and service comes with its own set of pros and cons. What works for someone else might not work for you. So, it is best to sit down and understand your needs best before making a decision.

Not sold on a gas fireplace? We've reviewed our favorite electric fireplaces if that's more of your thing.