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What is Better: Vented or Unvented (Vent Free) Gas Logs?

When it comes to choosing gas logs for your fireplace, the debate between vented and vent free models is as hot as the flames they produce.

But it's not really about which is "better".

Both technologies have their advantages and disadvantages. What's important is finding the technology that's best for your specific needs.

Every situation is different, including yours. At the Torch Guys, we take great pride in helping you find best product for YOU.

In this comprehensive guide, we'll delve into both technologies, outlining their pros and cons, and help you decide which is the ideal match for your home.

The Pros of Vented Gas Log Sets:

  1. Realistic Flame: Vented gas logs are renowned for their realistic flame pattern, closely mimicking a traditional wood-burning fire. This feature makes them a favorite for those seeking an authentic fireplace experience.

  2. Convenience - A beautiful fire at the touch of a button.

  3. Less Emissions Indoors: Since vented logs require an open chimney flue, the combustion gases are expelled outside, ensuring better indoor air quality.

  4. Variety of Styles: Vented gas logs give you the most options in terms of designs and sizes, offering versatility to match different décor styles.

The Cons of Vented Gas Log Sets

  1. Heat Loss: You are required operate vented log sets with the damper wide open. As a result, vented log sets are only 20-30% efficient because most of the heat produced is lost up the flue. *Keep in mind, a vented log set it is still two to three times more efficient than a straight wood burning fire since wood burning fires are zero percent efficient under the best of circumstances.

  2. Installation Limitations: Vented gas logs are only suitable for fireplaces with a working chimney, restricting their use in some homes.

  3. Drafty Chimney: with a vented log set the fire code requires the damper has to stay open -not fully open but open nonetheless - at all times. Even when the logs are off. This can lead to cold air coming down the flue and warm air escaping up the chimney during the colder months and vice versa during the summer. **Glass doors are a nice solution to help with drafty chimneys.

The Pros of Vent Free Gas Log Sets:

  1. Heat: Vent free gas logs are 99% efficient when operated in true vent free fashion (damper fully closed). Meaning almost all the heat produced comes back into your room .

  2. Emergency furnace: vent free gas log sets are often purchased as emergency furnaces. If you were to lose power durning the winter months, your vent free gas log set will provide a reliable source of heat for you and your family.

  3. Versatility:

    • Installation - Because no chimney is required, vent free log sets can installed in any room (except a bedroom) offering greater flexibility in placement.

    • Damper Control - an often overlooked but very nice feature of vent free gas logs sets is that you have total control over the damper position. Just because it's vent free doesn't mean you have to operate it in the true vent free fashion (with the damper closed). For example, lets say in the summer you want the ambience of a fire but you don't want the heat. You can use your vent free log sets with the damper fully open so most of the heat escapes up the flue.

  4. Cost-Effective: With higher efficiency and less fuel consumption, unvented gas logs are generally more cost-effective to operate.

The Cons of Vent Free Gas Logs:

  1. Air Quality Concerns: All fires need oxygen to burn and all fires produce by-products as part of the combustion process. Given the unvented nature of a vent free gas log set this can create concerns about air quality in the following areas:

    • The common by-products of a fire including CO, CO2, and water vapor have no where to go except back into your room.

    • Smell - another by-product of fire is smell. With a vent gas log set we tend to see three types of people:

      1. people that smell the odor and get headaches/watery eyes

      2. people that smell it but it doesn't bother them

      3. and people that don't smell it.

    • Oxygen Depletion - if you are operating your log set in true vent free fashion, you are taking air from inside the room to feed the fire, which will deplete your oxygen supply over time. However, almost all vent free log sets come with an oxygen depletion sensor (ODS). The ODS takes constant measurements from inside the room and automatically turns off your unit if it senses oxygen levels are approaching an unsafe level.

  2. Less Realistic Flame: The flame pattern of vent free log sets is less realistic compared to vented gas log sets. There are two reasons for this:

    1. You have less BTUs to work with in a vent free log set so can't achieve the same tall, brilliant flame pattern as a vented log set.

    2. The flames in vent free log sets are designed so they don't touch the logs to prevent carbon & creosote from being created. This creates a cleaner burn and allows you to operate in the vent free manner but it also produces a less realistic flame experience with the flames popping up in between the logs.

Comparing Vented and Vent Free Gas Logs

Many people will tell you deciding between a vented or vent free gas log set is easy.

  • If you want heat, go with vent free.
  • If you want good looks, go with vented.

And while that is true, there are other factors to consider as well. We've included them below to help you determine which gas log technology is right for you.

  1. Room Size and Ventilation: Larger rooms with good ventilation are better suited for vent free logs and will help minimize any air quality issues, while smaller, less ventilated spaces are better suited for vented log sets.

  2. Installation Constraints: Consider the practicality of installation in your home. If you have an existing chimney, vented logs are a viable option. For homes without a chimney, unvented logs are more suitable.

  3. Budget Considerations: Factor in the initial installation costs and ongoing operating expenses. Vented logs might have higher installation costs due to the need for a chimney, while vent free logs have lower operating costs.

  4. Versatility of Use - perhaps you want heat during the winter months, but not during the summer. A vent free log set with full control over damper position is a great option.

Gas Log Set Safety and Maintenance

Regardless of your choice, safety and maintenance are paramount. Proper maintenance ensures your gas log set performs safely, efficiently, and without issue for many years to come. Here’s how to maintain your gas log set:

  • Inspect and clean the burner and logs, removing any accumulated dust or debris.

  • Check for proper gas pressure and connections to ensure a consistent and safe fuel supply.

  • Clean the glass enclosure and ventilation system, if applicable, for optimal venting and appearance.

  • Inspect gaskets, seals, and other components for damage or wear and replace them as needed.

While homeowners can perform some of these maintenance tasks, it’s best to schedule annual maintenance services with a professional technician who can thoroughly inspect and service your gas log set, address developing issues, and provide expert advice for ongoing care.

In conclusion, the debate between vented and unvented gas logs isn't about which technology is inherently better; it's about which one aligns with your specific needs.

Consider the pros and cons of each, along with your personal preferences, room characteristics, and practical limitations. Whether you prioritize the authenticity of a roaring fire or the efficiency of a heat source, there's a gas log solution that's perfect for your home.