Customer Service Hours

8:00 AM EST to 7:00 PM EST



7525 Richmond Highway, Alexandria, VA 22306

Get Directions


2843 Rogers Drive, Falls Church, VA 22042

Get Directions


802 Rockville Pike, Rockville, MD 20852

Get Directions

Gas Fireplace Buyer's Guide

Is a Ventless, Direct Vent, or B-Vent Fireplace best? Learn about how they work, style options, the installation process, and the pros and cons.


So you've decided to purchase a gas fireplace! It could be the perfect design element to light up the living room in your new home or a fun new update to your current house. Either way, the first step is to decide what style of fireplace is the best fit for your lifestyle. The main styles of gas fireplaces include Direct Vent, Ventless, and B-Vent.

A direct vent gas fireplace also known as the traditional gas fireplace is one of the most versatile fireplaces and can be installed in almost any room in your home. The vent-free fireplace is designed to have almost 100% efficiency. As the name suggests, this model has no ventilation system, meaning all the heat from the fireplace is pushed back into your home. Finally, the B-Vent fireplace has the most realistic-looking flames of all the gas fireplace options. This is currently the least popular style of fireplaces, but that doesn’t mean it may not be right for your home!


Direct Vent Gas Fireplace

The direct vent gas fireplace is the most common fireplace installation today due to its versatility and safety. It can be installed in a home with an existing chimney, or into a home without an existing chimney, and have a ventilation system through an outer wall.

This style offers more venting flexibility than a B-vent and more efficiency; although it is not quite as efficient as a ventless gas fireplace.




How it Works

The direct vent gas fireplace uses a completely sealed venting system that uses Co-Linear Venting or Co-Axial Venting. Because the gas fireplace system is completely sealed, including a glass cover on the front of the fireplace, it means no oxygen is taken from inside the home for combustion, and no combustion byproducts, such as carbon monoxide, will be pushed into your home. This system will protect the integrity of the air within your home. On the other hand, a fair amount of heating will be lost through the ventilation.

This fireplace heats indoor air by pulling in cool air from the room to be heated near the hot firebox, and pushed back out into the room, creating a convection cycle. A blower accessory can be added to the fireplace. This is a fan that will help push more hot air into the room quicker. Another accessory that can be attached is a heat dump system, which will take the heat from the fireplace and push or “dump” it into another room.

Co-Linear Venting functions with a vertical chimney. This type of venting can only through the use of a vertical chimney. It’s a great option for a house with a pre-existing chimney because almost all co-linear vents exit through a masonry chimney. In this system two ridged parallel pipes exit through the roof. One of these pipes pulls cool air from the outside into the firebox for combustion. The second pipe works as an exhaust pipe pushing the exhaust fumes, carbon monoxide, and any odors produced by the fireplace, outside the home.

Co-Axial Venting is not as popular as co-linear venting because it can only be used for a direct vent gas fireplace (and not a B-Vent or masonry fireplace). It functions with two pipes, but instead of one pipe running linearly to the other pipe, one of the pipes in a co-axial venting system runs inside of the other pipe. The outer pipe pulls in cool air into the firebox for combustion, and the inner tube pushes the exhaust fumes out of the house. Because of this design, the hot air is insulated from the combustible materials composing the house by the cool air in the outer pipe. Instead of the ridged piping used in a co-linear venting system, the co-axial venting required flexible piping that can be customized to fit the configuration of your room. This type of system doesn’t need to terminate vertically, and therefore can be installed through an outer wall of a structure, and doesn’t require a chimney.

Deciding between a co-linear and a co-axial venting system will largely depend on the style of direct vent fireplace you choose, and if you have a chimney.

Installing a Direct Vent Gas Fireplace

Whether you require a vertical or a horizontal venting system, it can be easily fitted around beams, corners to be customized to your home. Because of this direct vent systems can be installed in almost any location. Because of the sealed nature of the design, these fireplaces are also safe for smaller rooms, or rooms with limited ventilation such as a basement or a bathroom.

It is always a good idea to check with your local building and fire codes before installing any kind of fireplace on your property. And finally, when in doubt it is always a good idea to consult an expert to inform you what type of systems are possible for your home.


You will be presented with the opportunity for some customization of your direct vent fireplace including choosing the type of logs that will match the aesthetic of your fireplace. Logs are most commonly available in oak, birch, or aspen, but there are lots of other wood options available. The logs can come in a split style or all whole logs. The flickering flame, usually and orange in color is more realistic looking than a ventless gas fireplace, but not quite as realistic looking as the B-Vent gas fireplace. This design offers a midpoint between flexibility and realism.

As for building styles, the options include:

  • Linear (most popular)
  • Traditional
  • Single-sided
  • Multi-sided
  • See-through
  • Corner

Safety for your Direct Vent Gas Fireplaces

Direct vent fireplaces are one of the safest options for installation. There is no flue, which eliminates the possibility of a backdraft from the fireplace gas valve. With certain clearances and added accessories such as a blower or heat dump system, it is safe to mount a TV above your fireplace.

Despite lower safety risks associated with this design, it is good to take standard fireplace safety precautions such as checking building and fire codes before installation and installing a carbon monoxide detector in your home in case of a gas leak. Lastly, you should get your fireplace serviced once a year to clean the burner, and check to see if it needs any gas fireplace repairs.


Ventless Gas Fireplace

Ventless gas fireplaces, also called vent-free fireplaces are another popular option, because as the name suggests, it requires no ventilation system such as a chimney or flue, making it the easiest fireplace to install. Because there is no vent for the heat to escape through this design it works at almost 100% efficiency pushing all of the heat it creates into the home. Because of the high-efficiency rating, this fireplace is more environmentally friendly by releasing the least amount of pollution.

How it Works 

The burners in ventless fireplaces are designed to burn cleanly, meaning almost all of the gas is burned up, eliminating most of the exhaust produced. This is why a vent is not needed in the fireplace system, all the gas is burned off, so there is no need to vent off the excess exhaust. This is not to say the ventless fireplace has zero byproducts. A minimal amount of CO gas will be released, as well as water vapor.

In the winter the water vapor byproduct can add some needed humidity to a dry home, but if too much moisture is added to the room it can cause mold and mildew. The moisture can be counteracted by either cracking a window to ventilate the room and tracking humidity levels in your home by purchasing a hydrometer. Another side effect of the water vapor is it will intensify any smells already present in the room such as perfume, or air fresheners.

Ventless Gas fireplaces create a cycle of heated air that forms a U-shape. Cool air from the room is brought into the firebox, typically the entry point is somewhere along the bottom of the fireplace. Once in the firebox, the air is mixed into the gas through a regulator to produce a flame. The heated air is then released back into the room through a vent at the top of the fireplace.

Since this fireplace draws in oxygen from the indoor room they are installed with an Oxygen Depletion Sensor (ODS) that monitors the room and will shut off the fire if the oxygen levels in the room get too low.

Installation of a Ventless Fireplace

Good news! The ventless gas fireplaces are often the easiest and cheapest fireplace to install because there is no need to install any sort of venting system. However, there are more restrictions on location for this fireplace. Because of the lack of venting it cannot be installed in small rooms or rooms with no windows where the oxygen supply is limited.

Just because this fireplace doesn’t require a chimney, doesn’t mean a ventless fireplace can’t be installed in a home with a pre-existing chimney; in this case, the damper should be closed. Ventless fireplaces are also specifically calibrated to burn a measured amount of air to gas ratio to produce minimal byproducts. This ratio will be different depending on the altitude of your home. If you live in a high-altitude locality be sure to double-check with the manufacturer or the professional completing the installation if the fireplace is set up correctly.

Because of the lack of ventilation, and the release of minimal amounts of CO into the house, there are some states and cities that do not allow ventless fireplaces to be installed indoors. some states include Canada, California, and Massachusetts, so make sure you check the guidelines of your locality.


The logs in ventless gas fireplaces are placed in a highly specific pattern around the burner to keep the flame from touching the logs, so there is no option for customization within the gas log installation process. 

But there are similar log design options with availability in oak, or birch depending on your preferences. The flame for the ventless fireplace is usually smaller and more blue-ish in color. Because no air is pulled into the firebox from an outside vent, the flames don’t flicker as much as in a direct vent and will burn in a pre-programmed pattern. This design has high efficiency and flexibility but a lower realistic look.

The building styles for ventless fireplaces are identical to direct vents.

  • Linear (most popular)
  • Traditional
  • Single-sided
  • Multi-sided (peninsula)
  • See-through
  • Corner

Safety for your Ventless Fireplace

Because of the small number of byproducts that can be released into the home, there are varying opinions on the safety of this fireplace. The fireplace must be professionally installed to the manufacturer’s requirements. This fireplace is also not recommended for people with lung conditions such as asthma or severe allergies. It is also recommended a ventless gas fireplace is only used for one hour at a time, and no more than four hours a day.

It is not required for these fireplaces to have a safety screen or glass barrier, but installing a safety screen on these fireplaces is increasingly popular. Also check national and state building codes to ensure the room you are installing the fireplace in meets the square footage and clearance requirements.

It is also recommended to have to logs of the fireplace annually. The logs on the fireplace are arranged in a specific configuration so the flames don’t touch the logs because flame impingement will occur and produces toxic gases. Therefore it is essential to get the fireplace checked out to make sure all the components such as the ODS and the burner are in working order.


B-Vent Fireplace

B-Vent fireplaces are also called Natural Vent Fireplaces. It is a good middle ground between a direct vent and a ventless fireplace, and most closely resembles an authentic wood-burning fire. One drawback of this type of fireplace is it is the least efficient in regards to heating a room, but because of its realistic appearance, B-Vent fireplaces are more often used as a design element to a room.

How It Works

A B-Vent fireplace is considered a middle ground between a direct vent fireplace and a ventless gas fireplace because similar to a Ventless fireplace, the B-Vent will draw in oxygen from the room to use in the combustion process. On the flip side instead of sending the CO byproduct from combustion into the house, the B-Vent has a chimney vent that sends the gases to the outside.

The B-Vent fireplace also often has an open-front design similar to a wood-burning fireplace. This not only makes the fire appear more authentic but is also how the fire takes in oxygen used for the flame. Unfortunately, most of the heat the gas fireplace produces will be sent to the outside along with the CO byproducts and odors, through the venting.

Installation of a B-Vent Fireplace

The main point that needs to be kept in mind for the installation of a B-Vent gas fireplace is the vent must be installed vertically. This means the pipe must exit above the roof of your home. The piping that is used in the B-Vent is a double-walled pipe, that provides insulation between the inner and outer walls, that will warm up the inner pipe and assist with the natural flow of air pushing the hot air outside.


Compared with the ventless and direct vent fireplaces, the list of styles for B-Vent fireplaces is shorter. On the plus side, the styles of B-Vents are incredibly customizable to be perfectly matched with your house’s design.

B-Vent fireplaces can be installed as an insert or a masonry firebox. The inserts can be built to seamlessly blend into your existing fireplace, or the masonry firebox can be customized for a more modern or traditional look.

Safety for your B-Vent Fireplace

B-Vent fireplaces are safe, like direct vent fireplaces, the byproducts of combustion are sent outside of the home. There is the possibility a downdraft from the outdoors will travel through the B-Vents piping, but many units have a sensor that will shut off the fireplace if this occurs.

Another element to be mindful of with a B-Vent fireplace is these appliances tend to not have a protector in front of the flame, which may not be ideal for homes with small children or dogs wandering close to the room with the fireplace. But this can be easily remedied with the purchase of fireplace doors or a screen.

Otherwise, it is good to have some standard fireplace safety precautions such as checking building and fire codes before installation and installing a carbon monoxide detector in your home in case of a gas leak. Lastly, you should get your fireplace serviced once a year to clean the burner, and check for gas fireplace repairs. 


Gas Fireplace Features

Ignition Systems: A gas fireplace is ignited with the use of a pilot light that is switched on to light the fireplace. Two different types of pilot lights can be utilized in gas fireplaces: the IPI or the CPI.

Intermittent Pilot Ignition (IPI): And IPI pilot light will only stay on when the fireplace is on. When the fireplace is switched off the pilot light will also shut off. This system is better for warmer climate areas or areas with long summers, anywhere the fireplace will be used sporadically. The IPI will save gas but will take longer to start the flame when compared to a CPI.

Continuous Pilot Ignition (CPI): The CPI has a continuously lit pilot light, meaning the pilot light is on constantly. Then with the flip of a switch, the thermocouple will send an electric current to the gas valve and open to send an immediate stream of fuel to the fire. CPI pre-heats the firebox, and exhaust pipes to remove extra moisture. The CPI is better for colder climates and long winters when the fireplace is used often and can be turned on quickly.

Battery Backup: is used in an emergency, in case of a power outage. It will ensure you can turn on the burner, but any lights or other accessories that require electricity will continue to not work in event of a power outage.

Controls: Part of the convince of gas fireplaces is they can be set up to be controlled by a remote or a wall switch. Check to ensure the ignition system for your fireplace can support these features. Some systems even allow a connection into a Smart Home, or directly to your thermostat.

Blower: A blower will increase the amount of heat delivered from your fireplace into the room it is situated. These blowers can be installed into a pre-existing fireplace, or are sometimes already built into a fireplace.

Power Vent: This is a type of venting ideal for apartments, where a chimney isn’t possible. It involves a fan that will circulate exhaust through the venting installed in the building.

Cleaners: using glass and hearth cleaners will make the front glass front looking sparkling and see-through for ideal viewing of your flame. Do not use cleaning products on the logs or burner to prevent damage. Instead, use a soft cloth and water without soap to clear up any soot.


We're Always Here to Help!

Purchasing a Gas Fireplace is a fantastic way to bring a beautiful focal point to almost any room. It will increase the value of your house, and your standard of living when you kick your feet up in front of the fire after a long day. As with any new appliance, it is important to review all your options and make sure you choose the right gas fireplace for your family.

Our experts are here to help! Call 866-848-3473, or send us an email with any questions today.

For more information browse our selection, or check out these other great articles from our Learning Center: