Vented or Ventless Gas Fireplace

Gas fireplace in a spacious living room with hardwood floors

One of the best feelings is cozying up to the warmth and crackling sounds of a wood fireplace. But constantly hauling wood to burn is a labor of the past, which is why many homeowners are instead opting for more efficient gas fireplaces. They provide the best of both worlds by combining the cozy ambiance with the convenience of a push of a button.

But when it comes to replacing your fireplace with a gas version, there are several options to consider. So, if you’re new to the world of gas fireplaces, don’t worry, we’ll help you sort it all out.

Below you’ll find a helpful guide that will help you understand the differences and benefits of vented and ventless gas fireplaces.

What’s the Difference Between Vented and Ventless Gas Fireplaces?

The main difference is their venting systems—the former requiring one and the latter not. This is due to their differences in heat production.

While vented gas fireplaces use outdoor air to provide combustion and burn at a lower temperature to create a realistic flame, ventless gas fireplaces use air from inside the home to provide combustion and burn at a higher temperature to ensure no gases are leftover.

Although ventless options are more efficient, they aren’t designed to be the sole source of heat for a property. Therefore, their difference in home heating function is usually the largest deciding factor.

Other considerations include:

  • Cost. Due to the differences in ventilation and installment needs, vented gas fireplaces are much more costly than ventless options. However, if you are planning to use a gas fireplace to heat your entire home, a vented option would be the better choice.
  • Appearance. Because vented gas fireplace logs allow the flame and log to touch, the appearance is much more realistic and more akin to traditional wood-burning fireplaces. Ventless options require the flame and log to be separate to burn cleaner and prevent soot and exhaust buildup. This eliminates the dancing flame appearance.
  • Flexibility. While vented gas fireplaces typically need to be installed near a wall, a ventless fireplace can be positioned in the middle of a room, or even outside.
  • Safety. Though ventless fireplaces burn fuel more cleanly, leaving little to no exhaust, over time very small amounts of fumes and sensitive gas odors can still remain inside the home if not properly used. Because of this, it’s suggested that they are not left running for longer periods of time, and to periodically allow some ventilation through an open window or door.

Vented Gas Fireplace Venting Types

If you’ve decided on a vented design, there are two different ventilation types to consider:

  1. Natural Vent (B-Vent). Like a more traditional wood-burning fireplace, these use the air inside your home for combustion and then vent gases outside through a single, vertical venting system. Their combustion chambers are not fully sealed and rely on natural buoyancy to release gases through a piping system.

  1. Direct Vent.These utilize a sealed dual-pipe venting system to release harmful gases out of the home and draw fresh air in. Venting is required either through the wall or roof. To allow for proper gas circulation and release, the firebox is completely sealed off.

Direct vent systems are the safest option in terms of indoor air quality based on the fact that the gases and odors are directly vented out of your home.

Related Topic:Gas vs. Wood Fireplace: Pros and Cons

Are Ventless Gas Fireplaces Safe?

The National Association of Certified Home Inspectors (NACHI) notes that although ventless gas fireplaces burn at nearly 100% efficiency, and are tested to operate at a safe level of cycling combusted gases back into the home, very small amounts of fumes and vapors still remain. And because some water vapors are created in the cleaner gas-burning process, this can also increase the potential for mold and mildew growth. For this reason, ventless gas fireplaces can be a greater concern for those with respiratory issues. However, to combat these risks, built-in oxygen and carbon monoxide detectors will automatically shut off the fireplace if unsafe levels of either are present in your home.

Regardless, some states have restrictions or specific code requirements that may also limit ventless options.

Can I Convert My Wood Burning Fireplace to Gas?

If you already have an existing wood-burning fireplace and want the benefits of a gas fireplace without installing a separate system, vented or ventless inserts or gas logs can be installed. Inserts sit inside metal framing and slide into your firebox, whereas logs can be placed individually. Installation is therefore much easier for both but does also require gas and electrical lines.

Vented vs. ventless gas fireplace inserts:

  • Vented Inserts. Proper gas exhaust vents will need to be installed through the chimney, and for a direct vent option, a glass panel will be sealed in front of the insert to prevent any gases from entering your home.
  • Ventless Inserts. Because ventilation isn’t needed due to combustion being created from indoor air, this insert is designed to block off the chimney opening.

Vented vs. ventless gas logs:

  • Vented Gas Logs. Unlike inserts, metal framing isn’t required, but proper gas exhaust vents still need to be installed.
  • Unvented Gas Logs. No venting requirements are needed, and therefore your chimney flue can be closed off. But these logs need to be properly arranged so that the flame is not touching the log to make sure the gas burns cleanly and safely.

Gas logs on their own are typically not an efficient heating option, therefore many homeowners choose to have them installed purely as decoration. Regardless, all installation options should be done professionally to ensure your fireplace is running efficiently and safely.

Learn More About Gas Fireplaces with Aire Serv

Still have some burning questions? While not all locations provide an installation service for agas fireplace, our technicians can help you make critical decisions about choosing the right one for your needs. And we can help you with all your other home heating and ventilation questions, including installation, service and maintenance. To learn more, call us today or request an appointment online.