Vented vs Ventless Gas Logs: Pros, Cons & Comparisons

Gas logs are a great way to warm up your home when the weather gets cold, but you’ll want to ensure you know the ins and outs of both vented and ventless gas logs before deciding on one option. Each type of gas log has unique pros and cons, so it’s important to consider each option before making your choice carefully. Vented vs ventless gas logs – which one should you choose? Read on to find out!

What are vented gas logs?

Vented gas logs are designed to be used with a wood-burning fireplace that has a fully functional chimney. The logs are placed on a grate inside the fireplace and are burned using natural gas or propane. A key feature of vented gas logs is that they must be used with the damper open, allowing smoke and other combustion byproducts to escape up the chimney.


  • Realistic-looking flame similar to natural wood fire
  • Do not require an oxygen level detecting system
  • Exhaust all combustion gases to the outside
  • Not banned in any state
  • It doesn’t release any smell into the living space


  • Not as efficient in heating the room as that of ventless logs
  • Consumes more gas than ventless logs

What are ventless gas logs?

Ventless gas logs are an alternative to traditional wood logs that do not require a vent or chimney. Instead, they burn using a small, self-contained unit placed inside the fireplace. These logs can be used with an existing fireplace with a closed chimney or as a standalone unit. They are not fitted with a vent, so they release fumes in the living space where they are installed.


  • More efficient in heating the room as compared to vented logs
  • Burn much clearer than vented logs, so don’t require venting out
  • Consume less gas for burning


  • The flame pattern is not as realistic
  • Banned in many states
  • Produce a peculiar odor that can trigger breathing issues
  • Needs a professional to install the ventless gas logs
  • Requires carbon monoxide and oxygen level detecting systems

Vented vs ventless gas logs: Comparison

If you’re debating the merits of ventless gas logs versus vented gas logs, there are many things to consider. Here are some of the main distinctions between vented and ventless gas logs so that you can choose wisely:

Chimney requirements

Vented gas logs must be installed in a wood-burning fireplace with a fully functional chimney. These logs need a chimney to operate because they produce carbon monoxide during combustion that needs to be exhausted outside the home. The damper must be open while the vented log set is in use. 

Ventless gas logs, on the other hand, do not require a chimney because they burn cleaner and hence don’t need to be vented outside. If you use ventless logs in a fireplace with a chimney, ensure that the damper is closed and the chimney is properly sealed so ventless logs can burn efficiently.

The ambiance of the fireplace

From an aesthetic point of view, vented gas logs are a clear winner. They produce a flame pattern that closely resembles the flames of natural wood burning. It is because the flame can spread out and dance around more, thanks to the ventilation provided by the chimney. Plus, most vented logs also recreate the ember glow of natural burning wood, which is a plus point. 

On the contrary, ventless gas logs don’t produce an authentic look of a burning fire that puts people off. However, ventless logs produce more heat than vented logs. So, if your main focus is the aesthetics of the fireplace and you have other sources of heat, you might want to go with vented gas logs.

Heat production

You have to open the damper every time you are using your fireplace. Because of chimney and flue involvement, there are more chances for heat to escape with vented gas logs. It makes vented gas logs a less efficient heat source than the ventless option.

If you are more concerned about heat than ambiance, then ventless gas logs are a better choice. Ventless logs are more efficient because instead of venting out, they circulate the heat produced back into the room, so it feels warmer.


Both types of gas logs have similar prices, but installation costs differ for vented and ventless fireplaces. Installing a proper chimney increases the overall cost of a vented fireplace which can be deciding factor for many homeowners.

Gas consumption

Vented logs use twice as much gas as ventless gas logs, so do keep it in mind when choosing between these two alternatives to natural wood logs. If you are concerned about your gas bill, choose the ventless option from these two gas logs.


For many homeowners, ventless logs are a safety concern as they recycle the air inside the house. This functionality can reduce oxygen levels inside the house, causing health issues. So an oxygen detection system is required with ventless gas logs, and it’s recommended to not use ventless gas logs for longer than 2 to 4 hours at a stretch.

With vented gas logs, you will not have to be concerned about oxygen level depletion or carbon monoxide detection as they are vented outside through the chimney and are completely sealed off from the indoors. So, vented logs are considered safer than ventless gas logs.

Odor issues

As vented gas logs are completely sealed off from the indoors and are vented outside, the smell of combustion and harmful gases do not enter the indoor air, so you will not notice any peculiar smell when vented gas logs are burning. However, ventless gas logs produce a specific smell that can be felt in the indoor space as the exhaust is not vented outside. So, if you have a sensitive sense of smell, there is a chance that you’ll not like the kerosene-like smell of burning ventless gas logs.


When choosing gas logs, another important factor to consider is the lifespan of the logs. Ventless gas logs produce more heat, which can shorten their lifespan. Ventless logs can show wear in 3 to 5 years if used frequently. On the other hand, vented gas logs typically last longer than ventless gas logs because they don’t burn too hot. Well-used vented logs can last up to 10 years or more. Vented gas logs are a perfect choice if you’re looking for gas logs that will last a long time.

Which one is better? Vented or ventless gas logs?

Both vented and ventless gas logs have their specific merits and drawbacks. So, the answer to this question depends on the suitable or better option according to your specific needs. Preferring vented or ventless gas logs depends upon your heating needs, the look you’re going for, and whether or not you want to worry about fumes. Vented logs are ideal for perfect wood-fire ambiance with less heat, while ventless logs can provide better heat with acceptable aesthetics.


Ultimately, the decision between vented and ventless gas logs comes down to personal preference and your type of fireplace. If you want the more realistic look and feel of a wood-burning fire, then vented gas logs are the way to go. However, if you’re more concerned with convenience and efficiency, then ventless gas logs may be your better option.

Charles John

Experienced HVAC technician with 8 years of experience in the industry. Capable of handling all sorts of heating and cooling equipment as well as proficient in operational management, construction-related techniques such as preventative maintenance, electrical troubleshooting and AutoCAD

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