Logs and inserts

VENTLESS

The term “Ventless” or “Vent-Free” comes from the fact that Ventless gas log sets don’t require a chimney or venting to operate. They are designed to achieve a clean, smokeless flame and to burn at nearly 100% efficiency so little to no gases remain after combustion.

Byproducts that do remain are typically made up of water vapor and carbon dioxide. Any toxic gases, such as carbon monoxide, will be minimal and within safe limits.

The flames are often blue and much smaller than the flames produced by a Vented set. Ventless gas logs can still achieve a realistic-looking fire, but the flames may not be as large or as authentic as a Vented version can produce.

As Ventless gas logs burn oxygen, water vapor is produced. Without venting for the water vapor to escape through, excess moisture in the form of condensation may appear on your windows or throughout the room. This is especially true with liquid propane-fueled logs.

Minimal amounts of moisture can be a great source of humidity in the winter, but larger amounts can lead to mold or mildew growth. If you notice excess moisture while using your Ventless gas log set, cracking a window near the fireplace will help to restore balance to the air in the room.

Since combustion air isn’t able to escape through a chimney, Ventless gas log sets may give off an odor when burning and will intensify any odors already present in the home. If you use air fresheners, incense, scented candles, perfume, or have a lot of dust or pet dander in your home, Ventless gas logs will strongly enhance those odors.

Although exhaust from Vent-Free gas logs is minimal, it can cause irritation to the lungs. If you or someone in your household has severe allergies, respiratory issues, like asthma or chronic bronchitis, or are sensitive to smells, then you should not install a Ventless gas log set.

Burners for Ventless gas logs are required by national code to be ANSI certified. They are factory assembled, then tested for safety and efficacy prior to shipping. Ventless burners cannot be modified in any way after they’ve been ANSI certified.

Ventless logs must be stacked around the gas outlets on the burner to prevent flames from coming into direct contact with the logs. If flames do touch the logs, carbon monoxide can be produced. The manufacturer typically determines how the logs should be arranged and will include instructions in the owner’s manual.

Vent-Free gas logs are considered safe, but they are relatively controversial due to the fact that if they aren’t functioning optimally, dangerous gases will be released into the home. Some states, like California, have outlawed Ventless appliances for indoor use altogether, while others have strict installation requirements.

As an additional safeguard, all Ventless appliances are required to have a built-in Oxygen Depletion Sensor (ODS) on the ignition pilot. The ODS monitors the amount of oxygen present in the room and will shut off the gas supply to the burner if the oxygen supply dips below the safe threshold of 18%.

The BTU output of Ventless appliances is limited to a maximum of 40,000 BTUs per hour to ensure adequate oxygen is left in the room. For installations in bedrooms and bathrooms, the maximum BTU output is even more limited, allowing only 6,000 to 10,000 BTUs, regardless of room size.

Ventless Pros

• 99.9% efficient
• More heat is introduced into the home
• Less gas consumption
• No venting required
• Equipped with Oxygen Depletion Sensor (ODS)
• All burners are ANSI certified, tested, and factory assembled

Ventless Cons

• Unnatural/unattractive flame appearance
• 6,000 - 40,000 BTU limit
• Burners are pre-assembled and cannot be modified
• Logs must stay in the predetermined arrangement to prevent flame impingement
• More installation restrictions
• Minimal exhaust remains in the home after combustion
• Produces an odor while burning and intensifies odors already present in the living space (air fresheners, incense, dust, pet dander, etc.)
• Increases humidity levels in the home
• Can cause lung irritation to those with severe allergies and chronic lung conditions