A see-through gas fireplace installed on a white wall in contemporary-style living room with a white couch, a yellow accent chair, and light wood furniture.

The Ultimate Gas Fireplace Buying Guide

Thinking of buying a gas fireplace? Learn what styles are available and how they work to choose the best model for your home!  

Last Updated: February 5, 2024

Gas fireplaces come in three distinct styles, including Direct Vent, Ventless (Vent-Free), and B-Vent.  

Direct Vent fireplaces are the most popular option, while Ventless fireplaces offer more flexible installation options. B-Vent models are the least popular, but they provide the most realistic flames.  

If you're thinking of adding a gas fireplace to your home, follow this guide to pinpoint the perfect design. We'll cover how each gas fireplace style works, ideal installation locations, and our best-selling models! 



What Is a Direct Vent Fireplace?

Direct Vent fireplaces are safe and efficient alternatives to traditional gas and wood burning fireplaces. These models don't require a chimney, but instead use a completely sealed venting system to operate. The system pulls fresh outside air into the firebox for combustion and exhausts combustion gases out of your home. This maintains indoor air quality and protects overall home efficiency while allowing the fireplace to work effectively.  

Direct Vent fireplaces also have glass fronts and safety barrier screens. Most models come with standard tempered glass, while others offer ceramic glass as an upgrade. 

How Do Direct Vent Fireplaces Work? 

Direct Vent fireplaces can work one of two ways — through a co-linear or co-axial venting system.  

In a co-linear venting system, two pipes run parallel to each other. One of the pipes pulls in fresh air for combustion, while the other pipe exhausts combustion byproducts. This type of system is most often used with Direct Vent fireplace inserts in masonry chimneys.  

Keep in mind, co-linear venting systems must be terminated vertically. This may affect the final placement of your gas fireplace. 

Co-axial venting systems consist of a pipe within a pipe, separated by 1 inch or more. The outer pipe draws in fresh outside air for combustion and the inner pipe expels combustion byproducts. As hot air exits your fireplace, the co-axial system pulls cool air in from outside. This creates a consistent flow of heat, known as a convection loop.  

For co-axial systems, your Direct Vent fireplace can have a flue outlet on the top or rear of the firebox. This allows you to tailor the venting configuration to the installation area. 

Where Can You Install a Direct Vent Fireplace?

With the correct venting system, you can install your Direct Vent fireplace in practically any room of the house. However, each city and state has specific code requirements. Make sure you check your local building and fire codes before installing your Direct Vent fireplace.  

Are Direct Vent Fireplaces Safe?

When installed properly by a licensed professional, Direct Vent fireplaces are one of the safest options available. 

Direct Vent models won't pollute your indoor air or negatively affect the air quality in any way. However, as a precaution, we recommend installing carbon monoxide detectors in your home. You should also consider having your gas fireplace serviced and cleaned at least once a year to make sure it stays safe and efficient. 

Make sure you don't run your Direct Vent gas fireplace without the safety barrier or glass front in place. If you remove the glass, your fireplace could release combustion gases into your home.  

What Direct Vent Fireplace Styles Are Available?

Direct Vent fireplaces are available in linear, traditional, single-sided, multi-sided (peninsula), see-through, and corner styles.  

Need some inspiration? Check out our best-selling Direct Vent fireplaces here

Our Most Popular Direct Vent Fireplaces

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What Is a Ventless Fireplace?

Ventless, or Vent-Free, gas fireplaces are freestanding units that don’t require a chimney or venting system.  

Without a chimney for hot air to escape through, all the heat produced stays inside your home. This makes Ventless fireplaces extremely efficient and economical heating sources.  

While the heat output is great, the overall look of the flame display is less intense than Direct Vent and B-Vent units. For this reason, Ventless fireplaces are primarily sold as heaters, rather than decorative appliances.  

How Do Ventless Fireplaces Work?

Ventless gas fireplaces function on a closed-loop system of indoor air. The system pulls cool room air into the firebox to complete combustion. The air cycles around the firebox before flowing back out into the room as heat. 

Ventless gas fireplaces burn at nearly 100% efficiency, leaving little to no gases behind after combustion. Typically, they only release a small amount of water vapor and carbon dioxide. Any dangerous gases, like carbon monoxide, will be minimal and within safe limits. 

As Ventless fireplaces burn oxygen, they produce moisture in the form of water vapor. You may notice some condensation on your windows or surfaces throughout the room. This is especially true with Propane gas. Some moisture can be a benefit in the dry, winter months, however, too much condensation can lead to mildew or mold growth.  

To remedy excessive moisture, crack a window open when you run your Ventless fireplace. You can also install a hygrometer to keep track of the humidity levels in your home. We recommend using a Ventless fireplace for one hour at a time and four hours max in one day to make sure your oxygen and humidity levels remain balanced. 

Where Can You Install a Ventless Fireplace?

Ventless fireplaces offer more flexibility with installation because they don’t require a chimney. However, they do have more restrictions for location, room size, media options, and elevation.  

Without a chimney or venting, air quality and oxygen depletion is a major concern. You cannot safely install a Ventless fireplace in a small or compact room where oxygen supply is limited.  

Ventless fireplace manufacturers calibrate each model to burn a specific air to gas ratio, ensuring minimal byproducts after combustion. If you live in an area with high elevation, like Colorado, you may need to have the gas outlet on your fireplace adjusted to offset the higher altitude and thinner air quality. You can have any adjustments made by the manufacturer when you purchase your fireplace or by a licensed gas professional during installation.  

Overall, Ventless fireplaces are safe to install in any home. The main concern is that your Ventless fireplace must always function optimally, or it will release harmful gases into your space.  

Some states, like California, have outlawed Ventless fireplaces for indoor use altogether, while states have strict installation requirements. Research your building, city, and state codes to see if there are any installation restrictions you need to follow.  

Ventless appliances must have a built-in oxygen depletion sensor (ODS) on the ignition pilot. The ODS monitors the oxygen level in the room. If the oxygen supply dips below an 18% threshold, the ODS automatically shuts off your gas supply.  

To preserve an adequate supply of oxygen, Ventless fireplaces are limited to 40,000 BTUs of heat per hour. For bathrooms and bedroom installations, they're limited to 6,000-10,000 BTUs, regardless of room size.  

Ventless fireplaces intensify any odors that are already present in your home. These can include air fresheners, incense, perfume, dust, and pet dander. Exhaust from the fireplace can also cause irritation to the lungs. If you or someone in your home is sensitive to smell or has respiratory issues, Ventless may not be the best option.  

What Ventless Fireplace Styles Are Available?

Ventless fireplaces are available in linear, traditional, single-sided, multi-sided (peninsula), see-through, and corner styles. 

Need some inspiration? Check out our best-selling Ventless fireplaces here

Our Most Popular Ventless Gas Fireplaces


What Is a B-Vent Fireplace?

B-Vent fireplaces, also known as Natural Vent, are the least popular gas fireplace option on the market. While they're more affordable than Direct Vent and Ventless fireplaces, they are inefficient and more difficult to install.  

How Do B-Vent Fireplaces Work?

B-Vent fireplaces feature an open-front design and operate similarly to wood burning fireplaces. They pull fresh air into the firebox from inside your home for combustion and use a vertical pipe to carry away exhaust and fumes.  

Most of the heat produced by the fire will escape through the vents. That's why B-Vent fireplaces are often used for aesthetic purposes, rather than as a supplemental source of heat.  

B-Vent fireplaces create a natural movement of air through insulated pipes. The airspace between the inner and outer pipe provides insulation to prevent heat loss, while the inner pipe warms up quickly. Once the pipe is warm, hot flue gases can exit through of the top of the pipe with ease. 

Where Can You Install a B-Vent Fireplace?

B-Vent fireplace installation is slightly more limited than Direct Vent or Ventless gas fireplaces.  

Like a masonry chimney, the venting for B-Vent fireplaces must terminate vertically through the roof of your house. This limits the location of installation to areas where a vertical pipe can run straight up to the roof.  

Are B-Vent Fireplaces Safe?

B-Vent fireplaces are safe. With a vertical venting system to exhaust combustion byproducts, dangerous gases won't build up in your home. Some models also feature a sensor that shuts off your fireplace if a downdraft occurs.  

What B-Vent Fireplace Styles Are Available?

B-Vent fireplaces are available as inserts and custom masonry fireboxes. With a custom firebox, you'll be able to choose from a variety of designs and finishes to match your home decor.  

Our Most Popular B-Vent Fireplaces


Two different ignition systems are available for gas fireplaces — intermittent pilot ignition (IPI) and continuous pilot ignition (CPI). For both systems, you can light the pilot with a switch on the fireplace.  

Once the flames ignite, a flame-sensing thermocouple registers the heat and sends an electrical current to the gas valve. The gas valve opens, sending a constant stream of fuel to the pilot light. If the flame ever goes out, the thermocouple will cool down, stopping the electrical current, and shutting off the gas supply.  

With an IPI, the pilot stays lit if the fireplace is on. Once you turn your fireplace off, the pilot light will go out. IPI’s are best for warm-weather climates, or areas where you won’t be using your fireplace every day. They will save you gas, however, the initial start-up will take between 15-20 seconds each time you turn your fireplace on.  

With a CPI, the pilot is continuous, meaning it will always stay lit unless there is an issue with the gas supply. CPI’s are best for cold-weather climates, or areas with long winters where you’ll be using your fireplace often.  

Most gas fireplaces also feature a battery backup, so you can turn your fireplace on during a power outage.  


Most gas fireplaces come with a hand-held remote control or a wall switch. You can choose a standard, On/Off remote control for basic functionality, or upgrade to a full-feature remote. With a multi-function remote, you can adjust the ignition, blower speed, heat output, flame height, thermostat, and timer.  

Some modern gas fireplaces can even pair with your smart home system. Integrated Bluetooth controls allow you to connect your fireplace to a smart device, offering the ultimate, user-friendly experience.  


Most gas fireplace manufacturers give you the option to choose the surround (trim) and media bed. Surrounds come in various widths, colors, textures, and materials, making it easy to match your home’s décor.  

Many homeowners add a set of gas logs to their media beds for an authentic-looking display. Other media options include sparkling fire glass, rustic river rocks, and contemporary fireballs.  


A fireplace blower is a type of fan that helps to blow more heat from the fireplace out into the room. Blowers don’t make gas fireplaces more efficient, but they do help to increase the overall heat output. Like a fan, blowers are not silent and will make a whirring noise while in use.  


Power venting can make your gas fireplace a lot more efficient, especially in large, commercial settings. Think condos, high-rise buildings, and tall apartment complexes where traditional venting won’t work.  

In a power venting system, a fan is installed where the venting system beings or where it ends. The fan pushes and pulls the exhaust through the venting and out of the building. Power venting systems allow installation through areas where venting must run down, across, and up to the roof. All power venting solutions are specific to the manufacturer.  


Cleaners are available to keep your gas fireplace looking like new. You can use a glass and hearth cleaner to remove any build-up from the inside of the ceramic glass front.  

To remove soot and residue from your gas logs or burning media, simply using plain water and a soft cloth will do the trick. Harsh cleaning agents can cause gas logs to become brittle over time, making them more susceptible to breakage.  

For a more in-depth look at how to care for your gas fireplace, check out our step-by-step maintenance guide.  


Need help choosing the best gas fireplace for your space? Call our NFI certified experts at 800.919.1904. 


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