Vented vs. Vent-Free Gas Logs

Vented and ventless gas logs are both wonderful but for different applications. Take a look at the chart below to see their different properties and decide which might be better for you.

Realistic?Venting RequirementsHeat ProductionEfficiency
Vented Gas LogsThese logs are great for ambiance and aesthetics; they are quite decorative and similar to a wood burning fire without the hassle of cleanup. You can recognize vented gas logs by the tall flames, big ember beds, and full orange-yellow color. The flames dance around, over, and through the logs making the logs look engulfed in flames. In most vented sets, the logs can be rearranged to the user's liking. This also contributes to make the vented set realistic.Your flue must be clear and working properly to funnel smoke and fumes out of the house. If you have a damper, it must be open while you burn. In any gas application, it is wise to install a carbon monoxide detector in case of a gas leak.While vented gas logs can produce more BTUs (a heat measurement) than ventless gas logs, most of that heat will escape up the flue along with the smoke and fumes. A set of vented logs is a good option if you love the ambiance a real fire creates, but you don't want excessive heat in your space (e.g. if you live in a warmer state or if enjoy sitting for long periods in front of the fire).Vented gas logs have around a 75% efficiency. This is slightly higher than the efficiency of most wood burning fires.
Ventless Gas LogsThese logs won't be quite as realistic as their vented cousins. The colors are less vibrant, and the flames are shorter. The flames won't engulf the logs, and the logs are not able to be rearranged.Ventless logs are designed to produce such a small amount of smoke and fumes that it isn't dangerous to allow it into your home. We recommend installing a carbon monoxide detector in the same room as the fireplace for added safety. In addition, check your local fire codes. Not all codes allow for vent-free gas logs.Even though ventless logs produce fewer BTUs an hour, no heat will escape through the venting. They thus provide more heat to the room than their vented cousins. Especially if you are used to a vented fire, the amount of heat produce might surprise you. A set of ventless gas logs is a good option if you want to warm your room significantly.Ventless logs have a 99.8% efficiency, which means they are great for the environment!

Safety Notes On Ventless Log Sets

  1. Always check your fireplace's manual to see if it is approved to have a ventless fireplace.
  2. Consider installing a carbon monoxide detector. Even when working properly, ventless logs have a 0.2% emissions rate. These emissions do contain carbon monoxide, a colorless and odorless poison. A detector ensures that the carbon monoxide won't built up to a dangerous level without your knowldedge.
  3. All manufacturers recommend only using your vent-free fireplace as supplemental heat, not as your 24/7 primary heating system.