What’s the Difference Between Vented and Vent Free Gas Logs?

Vent type refers to the way in which fuel is burned and where the heat output is directed from the gas logs. The vent type you choose will be determined by the look and heating efficiency you want, the type of fireplace in your home, and the local codes in your area. There are two options when it comes to gas logs vent types: vented and vent free.

Vented Gas Logs

  • Most popular type of gas logs.
  • More realistic, natural looking flame than vent free gas logs.
  • Flames wrap around the logs like real wood, increasing the resemblance of a real fire.
  • Logs are able to be repositioned since the flame actually comes in contact with the logs.
  • Must be installed in a fully functioning wood burning fireplace.
  • Heat output is similar to burning wood.
  • Heating efficiency is limited as the majority of heat is lost as it goes up the chimney.

Vent Free or Ventless Gas Logs

  • Greater heat output than vented gas logs.
  • Heat circulates the room instead of going up the chimney, creating a highly efficient heat source.
  • Does not have to be installed in a fully functioning wood fireplace.
  • Designed to burn cleanly.
  • To prevent soot and unwanted gases, the logs cannot be repositioned.
  • Requires an Oxygen Depletion System (ODS) to guard against unsafe emissions
  • Check local codes as certain states and cities do not allow the use of vent free gas logs.

Measure Your Fireplace

Measure Your Fireplace
  • Measure a clean, open fireplace free of obstructions.
  • Measure the front opening of the fireplace. (A)
  • Measure the back width of the fireplace. (B)
  • Measure the depth of the fireplace from the back wall to the front. (C)
  • Measure the inside height from the floor to the top of the fireplace. (D)
  • Read How to Measure Your Fireplace to learn more.

What Fuel Type Do I Need?


Natural Gas Logs

  • Most common fuel choice for gas log installations.
  • Lighter than air – dissipates when released.
  • Great choice when other natural gas appliances are already owned.

Propane Gas Logs

  • Requires a safety pilot ignition system.
  • Heavier than air - collects at ground level if valves are left open when not in use.
  • Convenient in areas where natural gas is unavailable.

Gas Log Ignition & Control Method

Match Light

Match Light

  • Most basic lighting method – no safety pilot included, just logs and burner.
  • For use with natural gas only.
  • Light the fire by placing a match or lighter near the burner, then turning on the gas with the key valve.
  • Flame height is controlled by the key valve (located outside of the fireplace in the wall or floor).

Manual Safety Pilot

Manual Safety Pilot

  • Also referred to as a standing pilot and resembles a hot water heater pilot.
  • Manually lit and controlled through a knob.
  • Stays lit all the time (standing pilot).
  • Battery powered millivolt ignition can be used without electricity.
  • Types of Controls
    • With Basic On/Off Remote: Remote turns the burner on and off, but does not control the flame height.
    • With Variable Flame Remote: Remote turns the burner on and off and can control the flame height.
    • With On/Off Wall Switch: Wall switch turns the burner on and off, but does not control the flame height.

Electronic Ignition

Electronic Ignition

  • Ignites only when the system is being started.
  • Does not burn the pilot while not in use, saving energy (non-standing pilot).
  • Types of Controls
    • With On/Off Remote: Remote control ignites the pilot and then the burner, but does not control the flame height.
    • With Variable Flame Remote: Remote control ignites the pilot and then the burner; can control the flame height.

If you still have questions, call us at 1-866-292-7470!


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