Fireplaces, where people gather around to enjoy a warm and cozy atmosphere, can make a world of a difference when it comes to interior design. Whether you're moving into a new house or planning on renovating an outdated living space, you might find yourself in a bit of a pickle as you start exploring all the available—and sometimes, overwhelming—fireplace options on the market. To relieve some of the shopping frustration, we'll walk you through ways you can identify the type of fireplace you have so that you can find the perfect vent setup that is right for your home.
Masonry Versus Prefabricated Factory-Built Fireplaces
Question #1: Can you spot the difference between a masonry fireplace versus a prefabricated factory-built fireplace in the above images? (Read on to find out helpful hints. *Answer is at the end of the article!)
Identifying the type of fireplace your home has, or will have, can be admittedly trivial. We get it. All fireplaces have the same basic functionality of producing a flame, so how do I know which one I currently have—or need—for my living space?
If you have an open hearth or bifold doors that can be opened to the firebox—the area where fuel combusts—and a chimney that terminates up through the roof, then you most likely have a masonry fireplace. A masonry fireplace—identifiable by its all-brick and mortar, stone, or block build—is commonly seen in older homes. While this type of fireplace is traditionally seen burning wood, it can be converted for use with gas. If your fireplace has a log lighter—a long rod with ports—that starts a fire on real burning wood, then this is another sign that you have a masonry. Another good indication is if it has a damper clamp, which is a small c-shaped metal part or long metal lever, above the inside of the firebox. This tiny, but important fitting, is an essential component for controlling drafts in a flue to allow harmful emissions—such as carbon monoxide—to escape up through the roof. You should find an all-stone or brick interior when looking up the inside of the chimney and a relatively wide smoke chamber opening.
How to identify a masonry:
- Open hearth with no doors, or with bifold doors
- An all-brick or stone build (includes firebox and chimney interior)
- Damper clamp
- Wide smoke chamber opening
- Log lighter (long rod with ports, usually located towards the rear of the firebox)
On the contrary, if you're looking at a metal firebox you most likely have a prefabricated fireplace. These pre-built units are made in the factory and are seen mostly in newer homes. Depending on the model, they can burn gas or wood. Some manufacturers have improved the design of their prefabricated fireplaces so well, that it's easy to mistake one for a masonry. But generally speaking, they can be identified by a visible metal surround (usually with venting louvers at the top or bottom), a firebox made of cast refractory panels (that can sometimes mimic the appearance of brick), and a metal interior-based chimney system (typically covered by vinyl or siding that matches with the rest of the home). These types of fireplaces usually come attached with a rating plate that identifies the make, model, and serial number (but hold tight, we’ll discuss rating plates a little later in the article).
How to identify a prefab fireplace:
- Visible metal surround (look for venting louvers on the top or bottom)
- Metal interior chimney system
- Firebox made of cast refractory panels
- Rating plate
Gas Fireplace Vent Types
Now that we have masonry and prefabricated fireplaces defined, let's dive a little deeper into the different vent types and their requirements.
Vented
If you prefer the appeal of a wood burning fireplace but want the convenience of gas, upgrading your living space with Real Fyre Vented Charred American Oak Gas Logs and a Real Fyre Vented G45 Fireplace Burner makes it possible. This burner system can produce an impressive heat output anywhere from 30,000 to 110,000 BTUs.
What features to look for:
- An open hearth or bi-fold doors with a firebox that can burn solid wood fuel
- Damper clamp, above the inside of the firebox, that opens to the smoke chamber and flue
- An all-brick or stone chimney that terminates vertically up through the roof
- Full-bodied yellow flames with a realistic flame pattern
- If you have a current set up with gas logs, check the log placement and the flame display
- Do the logs allow flexibility in terms of arrangement?
- When the fireplace is turned on, do the flames touch and wrap around the logs?
- If the answers to the above two questions are “Yes”, then you most likely have a vented setup
Vented fireplaces, which must be installed in an operable wood burning masonry with the damper fully opened, requires a flue or ductwork through the chimney. Since it utilizes warm air from the room to feed the fire for combustion, having adequate ventilation is crucial for allowing carbon monoxide to escape. While some heat is lost when it escapes up through the chimney, this type of fireplace—aside from wood burning fireplaces—generally produces the most heat, typically anywhere from 100,000 to 300,000 BTUs maximum (to learn more about British Thermal Units, check out our Starfire's Guide to BTUs article). Vented fireplaces can be used with natural gas or propane and showcases a more robust natural flame pattern that closely resembles that of a traditional wood burning fireplace.
Vent-Free
The Loft Series Vent-Free Gas Burner by Empire Comfort Systems offers boundless possibilities for installation and can easily transform outdated living spaces into contemporary social gatherings, especially when decorated with fire glass.
What features to look for:
- A prefabricated factory-built fireplace certified for use with vent-free gas logs, or a vent-free firebox enclosure
- Sparse blue-cast flames that have a less natural flame pattern
- If you have a current set up with gas logs, check the log placement and the flame display
- Logs DO NOT allow flexibility in terms of arrangement
- When the fireplace is turned on, there should be no flame impingement—meaning the flames should not touch the logs. The flames should look as though they’re peeking through the gaps in the log arrangement
Vent-Free fireplaces don't require a chimney for ventilation since air from the room, used for combustion, is circulated back into the home. Considered to be 99% efficient, these units burn fuel cleaner and more efficiently as only it uses half to two-thirds less gas to heat up the room. They require the use of an oxygen depletion sensor, a device that monitors oxygen levels in the room, to maintain safety. Compared to vented fireplaces, a vent-free fireplace creates a less realistic flame pattern—with no flame impingement—and can provide supplemental heat. But their BTUs generally maxes out at 40,000 BTUs. They offer more flexibility in terms of fuel use, and can be used with natural gas, propane, or bio-ethanol fuel—depending on the product's configuration. However, this unit is subject to State and Local Codes. Therefore, can only be installed in vent-free approved fireplaces such as: in a solid fuel burning masonry with the damper closed off, in a prefabricated factory-built fireplace certified for use with vent-free logs, or in a vent-free firebox enclosure.
B-Vent (Natural Vent)
B-Vent fireplaces utilize a single wall pipe venting system to exhaust emissions vertically up through the roof.
What features to look for:
- An open hearth, or one with bifold doors that can open to the firebox
- A relatively small, round flue opening above the firebox that vents vertically up through the roof
B-Vent, or natural vent fireplaces, don't have a fixed glass panel front since warm air from the room is used to fuel the flames with oxygen. It utilizes a single wall pipe venting system that exhausts emissions outside, vertically up through the roof for necessary ventilation and combustion. They're suitable for use with natural gas and propane and can produce heat between 20,000 to 30,000 BTUs maximum. B-vents cannot be modified as they are designed to come with factory-installed logs specific to the unit.
Direct Vent
A sealed, non-operable glass front is a characteristic unique to direct vent fireplaces, such as the 42" Marquis II Direct Vent Gas Fireplace by Majestic Fireplaces.
What features to look for:
- A fixed, non-operable sealed glass door that cannot swing or slide open, unless with a tool
- A switch on the wall that lights up your fireplace (this should be in addition to the first bulletpoint)
- A relatively small flue opening above the firebox that vents vertically up through the roof, or horizontally through the sidewalls
Direct Vent fireplaces—which are tested and certified to be sold as a complete unit with the burner, fireplace media, and fireplace system combined—are sealed with a fixed, non-operable flex panel or glass screen covering the front meant to keep combustion isolated from the interior of the home. Unlike B-Vent fireplaces, which utilize a single wall pipe venting system, direct vent units expel byproducts through the walls via a dual, two-pipe chamber venting system. One pipe draws fresh air from outside of the home into the firebox for combustion while the other pipe simultaneously exhausts harmful byproducts outside of the home. This can be terminated horizontally through the sidewall or vertically up through the roof. Since air from the interior of the home isn't used for combustion, it allows for more convective heat and doesn't affect indoor air quality. Suitable for use with natural gas or propane, it offers more flexibility for placement since it can be installed into a wall or an existing open masonry. They typically range between 20,000 to 60,000 BTUs. Like b-vent fireplaces, direct vent fireplaces cannot be modified as they’re also designed to come as a complete unit with the firebox, media, and chimney system.
At a Glance
One of the easiest ways to narrow down what type of fireplace you have is to check the doors—or lack thereof—it has. If your fireplace is an open hearth or has bifold doors that can easily open to the firebox, then you most likely have a vented, B-vent, or vent-free unit. If there's a fixed glass front that cannot swing or slide open without the use of tools, then it’s a good indication that you have a direct vent unit.
To take some of the guesswork out of the equation, one of the simplest ways to identify what type of fireplace build you have is to check to see what type of door or—lack of door—it has. A door-less open hearth, or one with bifold doors that can be easily opened to the firebox, usually indicates a Vented, B-Vent, or Vent-Free unit. A sealed single-pane fixed glass front—which cannot be easily opened—indicates a Direct Vent unit. While some Direct Vent inserts out there can have bifold doors, they're intended more for ornamental purposes and are locked into place. They cannot be opened unless a tool is used.
Question #3: Can you locate the rating plate in the above two images? (***Answer is at the end of the article!)
If you're still unsure, another way is to identify the make, model, and serial number is by checking the appliance rating plate—which will typically also specify the type of fuel and the type of materials that can be burned in the fireplace. The rating plate can be used to look up the owner’s manual, if it is not readily available at your disposal.
Where can I find the fireplace rating plate?
- Behind the unit
- Underneath the lower louver
- Upper baffle—a metal deflector plate inside the top of the firebox
- Inside the fireplace opening, on the sides
- Behind an access panel or louver that opens to the plumbing or valve
Wood burning and prefabricated fireplaces have a metal plate while gas fireplaces usually have stickers or tags either on the burner or on the insert itself. However, some older homes with masonry-built fireplaces and chimneys won't even have a rating plate at all. If you fall into the latter category, you're probably stumped thinking, "Now what"? Read on to find the next best solution.
Criteria Check List Before Purchasing and Installing
If you're not too keen about hunting down the rating plate or doing guesswork, you can have a certified professional inspect your appliance or simply email or call our staff with pictures of your fireplace so that we can help you identify what you have.
It can be tricky trying to identify what type of fireplace you have. But if you have an idea of what you want—but just aren’t positive on what you need—asking yourself the following questions might help narrow down your options:
- What is your budget?
- What is the fuel source and ignition type you intend on using? You’ll need to consider what gas and/or electrical supply lines are available to your home. To get a more in depth break down on the pros and cons of electric, gas, wood, ethanol/gel fireplaces, read our Finding the Right Fireplace for Your Living Space article.
- Where in your home would you like your fireplace to be located? Depending on the fireplace model, you’ll need to consider your floor plan and the termination requirements. Is there venting needed in order to operate the fireplace? If so, how—vertically or horizontally—does the flue or vent pipe need to run to be terminated? Also consider clearance requirements to combustibles.
- In relation to #3, what are the specific State or Local Building Codes for your area?
- Do you want heat or something just more for decoration?
- What style are looking for?
Before committing to a purchase and modifying your home, having some of the above questions answered can go a long way. But when all else fails and you're still unsure by the end of this article—send a message on our live chat, reach out to us on our Contact Us page, or call our staff at (866) 578-8538 with pictures of your fireplace so that we can help you identify what you have.
Quiz Answer Key:Question #1: Can you spot the difference between a masonry-built fireplace versus a prefabricated factory-built fireplace?
*Answer: Left image is a wood burning fireplace, right image is a direct vent insert (a type of prefabricated fireplace). Although the fireplace in the left image has a visible copper-tone metal surround, you can clearly see that it is an open hearth. Plus, the damper clamp—which is crucial for vented and wood burning fireplaces, is peaking out right above the firebox. The fireplace in the right image, has a zero-clearance, meaning that there isn't a clearance required between the firebox and combustible materials. While louvers aren't present, it has a single panel front—a characteristic unique to direct vent fireplaces.
Question #2: Blowers and fans can only be installed in vent-free and direct vent fireplaces. They cannot be installed in vented fireplaces. Why?
**Answer: Vented fireplaces cannot have a blower or fan installed as they require adequate ventilation for terminating harmful emissions, like carbon monoxide, outside of the home.
Question #3: Can you locate the rating plate tag in the above two images?
***Answer: Left image should be obvious, but the rating plate (white sticker tag) is hidden inside the lower access panel. In the right image, the burner system's rating plate is located on the side of the burner. It's hidden right underneath the grate's front left leg.