Glass Fronted Gas Fireplaces: Are They More Efficient?

Gas fireplaces offer the traditional comfort of a live fire without the mess or cleanup. Many gas fireplaces have a glass front—especially indoor ones—while some have an open front. What’s the difference? Does the glass make the fireplace more efficient?

Glass-fronted gas fireplaces are more efficient as the glass front prevents room air from being used for combustion. Therefore room air is also not vented out through the top of the gas fireplace. When a glass front is used, the room’s air warms slowly using both convection and radiant heat from the fireplace’s pane.

What makes a glass-fronted gas fireplace more efficient? Continue reading, and let’s get into the details. For the purposes of this article, when the word “fireplace” is used, it is used in reference to a gas fireplace unless otherwise specified.

Are Glass Fronted Fireplaces More Efficient?

Glass-fronted fireplaces are more efficient in regards to raising the temperature of a room. This is because room air is neither used to fuel the fire nor is the room air being vented to the outside. The glass pane blocks the room air from being used and instead radiates heat from the pane.

To understand how a glass-paned fireplace is more efficient, let’s briefly talk about how the fireplace works. Glass paned fireplaces have a vent system to provide air to the flame and to release the exhaust outside.

This method of air flow means that air is not taken from within the room. The benefit to this is that as the room’s air warms from the fireplace, it stays in the room and does not escape outdoors through the exhaust vent.

Additionally, many glass-fronted fireplaces have a method of convection that allows the room air to be circulated through or blown via a fan system back into the room.

What Are The Differences Between An Open Front And A Glass Front?

The main difference between an open-front fireplace and a glass-front fireplace has to do with the source of air and venting system. Open front systems use the room’s air as an oxygen source, whereas glass front systems are sealed from the room air and use a vent to source outside air.

There are a few other differences between the two types of fireplaces that I will briefly lay out.

An Open Front System: This type of fireplace imitates a traditional wood-burning fireplace. Although you won’t need to throw new logs on the fire, and it does not crackle, it does have that rustic charm. In this system, you will feel the radiant heat as there is no pane blocking the flame’s heat.

Furthermore, a no glass system offers a realistic fire with modern, easy-to-use features, especially on an outdoor fireplace. In these systems, the flame is typically more blue in color—especially in vent-less systems.

A Glass Front System: This type of fireplace offers the comfort of a live fire with efficiency for supplemental heating. This system, as mentioned above, uses vents for air supply so that the room air is not being replaced or removed. This slowly raises the room’s thermal temperature.

One other difference to note is that a glass front system is safer since the flame is behind glass and out of reach. In these systems, the flame is more yellow in color.

Do Direct Vent Gas Fireplaces Require A Glass Front?

A direct vent fireplace system requires a glass front to prevent room air from being used in the fireplace. The direct vent system is designed to source all the air from outside and to exhaust air outside.

A direct vent fireplace also has a realistic yellow flame and needs that exhaust vent to get rid of any smoke or gases.

On the other hand, a ventless fireplace system is a popular feature on the market. This type of fireplace has no glass panel (or may have a partial glass front) encasing the fire. The air of the room or the outdoor setting provides the air to combust and fuel the fire. Typically, with these ventless systems, there is little to no exhaust so there does not need to be an exhaust vent or chimney.

Think of those outdoor gas fireplaces that mimic a bonfire, or a fire table in the middle of a restaurant—those are usually ventless fireplaces. They provide a level of radiant heat when you are directly next to the fire, but without a blower, they are not efficient at raising the thermal temperature of a room.

Is A Gas Fireplace More Efficient Than A Wood-Burning Fireplace?

A glass-front gas fireplace is more efficient than a traditional wood fireplace. This is because the gas fireplace system has been designed to both pump warm air back into the room and prevent room air from escaping.

A traditional fireplace loses a considerable amount of heat through the chimney. In fact, without a blower, wood fireplaces are not especially efficient at room heating. However, with a blower in use, heat can be distributed better.

Another consideration is that when the fireplace is not in use, the glass front system blocks the room air from escaping through the chimney or vent system. In a traditional wood-burning system, if the damper is not closed or functioning properly, room air can be lost through the chimney and a cool draft can enter.

Gas Vs Wood Fireplace; The Pro’s And Con’s

Gas fireplace pros:

  • Cleaner fuel
  • Efficient
  • No cleaning
  • Minimal maintenance

Gas fireplace cons:

  • Cannot burn your old papers or cardboard
  • No crackling fire

Wood fireplace pros:

  • Ambiance and a crackling fire
  • Can pick your logs, including ones that smell good
  • You can roast a marshmallows

Wood fireplace cons:

  • Requires maintenance
  • Requires work to start the fire
  • Possible to have smoke billow in your room

Dan Westfield

Hi everyone! My name is Dan and I currently have two fireplaces, a wood-burning and a gas one. I cannot live without them and love to share my passion with you all!

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