Why Do Some States Ban Unvented Gas Fireplaces? (2023)

If you are building a new fireplace or looking to update an existing brick fireplace, you have the option of using a vented or vented gas fireplace in most locations in the United States. Ventless gas fireplaces are highly efficient and are characterized by the lack of a chimney or other ventilation. In fact, after aArticle from the Journal of the Air & Waste Management Association, nearly 23 million consumers use ventless gas heating products. Who Bans Ventless Gas Fireplaces and Why?

Currently, only the state of California has a total ban on these fireplaces, with states like Massachusetts recently lifting their bans. So, these fireplaces are legal in 49 states, with some states having more restrictions than others. Even then, each county has different codes, so what's allowed in one city may not be allowed in a city right around the corner. It's important to check with your county's building codes as to what is and is not permitted for use in your home or business. In this article, we discuss perspectives for both the pros and cons of banning ventless fireplaces to ensure you can make the most informed decision for your specific needs.

The case for flueless gas fireplaces

The main benefit of flueless fireplaces is their improved efficiency compared to flue options, with flue loss reaching up to 99%. This higher efficiency is achieved through complete or perfect combustion and heat storage in your home.

Complete combustion uses the perfect ratio of oxygen and fuel to produce relatively harmless by-products — heat, carbon dioxide (CO2), water vapor (H20), and nitrogen (N). Of course, we don't care about water vapor (and ANSI-certified burners don't produce enough humidity for mold to grow in your home), and low levels of carbon dioxide and nitrogen don't bother us either. In fact, the air we breathe is made up of about 20% oxygen and 80% nitrogen, with about 0.04% of the air being carbon dioxide.

(Video) Gas Fireplace 101 - Vented, Vent-Free & Direct Vent Gas Fireplaces Explained

pro tip: If you wish to work without a vent, regardless of whether your county code requires it, we strongly recommend purchasing an ANSI certified unit, which always includes additional safety features such as an oxygen deficiency sensor (ODS).

Why Do Some States Ban Unvented Gas Fireplaces? (1)Ventless gas fireplaces do not require expensive brick chimneys or other venting systems.

Because flueless fireplaces do not use chimneys or similar venting solutions, they have no connection to the outside, meaning all of the heat generated by combustion is emitted directly into your space. In this scenario, you have minimal heat loss. If you've ever sat near a door on a chilly winter's day, you've felt a rush of freezing cold air when that door opened. Leaving the door closed sounds a lot warmer, doesn't it?

Another benefit of ventless fireplaces is that they are easy and inexpensive to install. Since these fireplaces do not require ventilation, you have much more flexibility as to where you can place them in your home. And no ventilation means you spend less material on this installation. An added plus for these fireplaces, and all gas fireplaces, is that there is no ash to remove. Unlike wood burning fireplaces that use a solid fuel, gas fuel leaves no charred residue to deal with.

(Video) Taker caution with ventless fireplaces

The case against flueless gas fireplaces

We have discussed how ventless gas fires can be efficient when they achieve complete combustion, but we also need to discuss what happens when combustion is incomplete.

Incomplete combustion occurs when the air in your room contains either too little or too much oxygen. When less oxygen is available to take part in combustion, the by-product carbon dioxide (CO2) turns into carbon monoxide (CO). Likewise, if there is too much oxygen in the combustion, nitrogen oxide (NOx) remains instead of just nitrogen (N).

Carbon monoxide is an odorless, colorless, tasteless, and flammable gas that is dangerous and highly toxic. When inhaled, this gas reduces the oxygen your cells receive. Effects vary with intensity and duration of exposure, but high levels of CO cause cellular asphyxiation and can lead to death. Nitric Oxide is similar, although not necessarily as dangerous. NOx primarily affects your lungs, and short or small doses can cause temporary common problems like coughing. Prolonged or high exposure can lead to significant lung damage, which in extreme cases can lead to death. It's these two dangerous gases that led California to completely ban ventless gas fireplaces and why so many other states and counties have restrictions on them.

Both of these by-products are a very serious issue and definitely something to consider when choosing the right fireplace for your home. This is exactly why we strongly recommend purchasing only ANSI certified unvented systems.

(Video) Ventless Gas Fireplace

Why Do Some States Ban Unvented Gas Fireplaces? (2)Real Fyre vent-free systems are ANSI certified and a popular brand with vent-free customers.

These certified systems include an oxygen deficiency sensor (ODS) that shuts off the gas when oxygen levels fall below safe levels. With an average concentration of oxygen in the air of 20% and these ODS systems triggering at 18%, there is little chance of the oxygen dropping to levels that cause harm.

In addition, all ANSI-certified burners undergo rigorous testing to ensure levels of hazardous by-products are exceptionally low. ThisArticle from the Journal of the Air & Waste Management Associationsays it most clearly:

“Currently, there is no evidence in the peer-reviewed scientific literature that chimneyless gas heating products manufactured to current ANSI codes and maintained in accordance with the manufacturer's instructions are the cause of health-related problems in the home or expected emissions. There is also no evidence that the small amounts of carbon dioxide, carbon monoxide or nitrogen dioxide produced as normal combustion products from ANSI code compliant unvented gas heaters exceed applicable indoor standards.”

(Video) Real Fyre Vented vs Vent Free Gas Logs

The arguments against ventless gas fireplaces only apply when it comes to non-ANSI certified burners, and we totally agree that these can pose a risk. When installed and maintained according to the instruction manual, ANSI certified ventless gas fireplaces are unlikely to put you or your loved ones at risk. If you plan to install a flueless fireplace in your commercial building, make sure it is an ANSI-certified fireplace.

The best choice for your home

Ultimately, unvented gas fireplaces come with a higher risk than their vented counterparts—although even vented fireplaces still carry some risk. However, if you only use ANSI certified ventless burners and follow the manufacturer's instructions for installation and maintenance, the risks are greatly reduced. Even better if you make sure your home or business is also equipped with a carbon monoxide alarm. We continue to wholeheartedly support gas fireplaces, both vented and unvented, as a viable supplemental heating solution. But make sure you buy ANSI certified for vent-free.

We've outlined the arguments for and against ventless burners, but understand that these choices are important and want to make sure you are completely confident in your choice. If you have done further research or just want to ask us some additional questions, we're happy to help in any way we can. You can reach our NFI certified team by phone at 866-578-8538, via live chat on our website, or by filling out ourcontact us form.

Sources + Additional Reading

Probabilistic assessment of the potential indoor air effects of ventless gas heaters in energy efficient homes in the United States,Journal of the Air & Waste Management Association


Ventless Gas Fireplaces: Are They Safe?

ANSI Z21.1.2-2016 - Gas Fired Space Heaters, Volume II, Unvented Space Heaters

Main image: Dog relaxing in front of a ventless gas fireplace.


Why are ventless fireplaces illegal? ›

Massachusetts, California, and a number of other states in the U.S., as well as Canada and other countries, have outlawed ventless gas fireplaces due to the aforementioned safety concerns. Many individual municipalities, too, have outlawed these appliances in states where they are otherwise legal.

What states do not allow ventless fireplaces? ›

In fact, in 1996, they were banned by Alaska, Montana, Minnesota, New York, and Massachusetts, however, after strong influence by the industry, all but California still bans them.

Are unvented gas fireplaces safe? ›

Are Ventless Gas Fireplaces Safe? Ventless gas fireplaces emit dangerous and noxious gasses into the room they are operating. Without proper ventilation and safety systems in place there can be serious health risks associated with burning gas in a ventless fireplace.

Which is safer vented or ventless gas fireplace? ›

Ventless fireplaces are designed to burn gas more efficiently than vented versions, resulting in far fewer fumes and no need to install a flue.

How long can you leave a unvented gas fireplace? ›

In short, you really shouldn't let a gas fireplace on for too long—specifically more than three hours at a time.

Do ventless fireplaces cause headaches? ›

The smell of burning gas can cause sensitivity, headaches, and other issues in some people. This can especially be the case with vent-free gas logs. These types of logs don't have a chimney or vent to remove the fumes produced by the fire, so the smell is typically stronger.

Can you make a ventless fireplace vented? ›

Answer: Unfortunately, there is no way to convert a ventless fireplace into a vented fireplace. Ventless fireplaces are not designed to have a vent added to them. Your only alternative is to tear out the existing ventless fireplace and replace it with a vented fireplace.

Which is warmer vented or ventless fireplace? ›

Ventless fireplaces produce more heat than vented fireplaces, but vented fireplaces look better. The different strengths of the two types of units will appeal to different people.

Which is safer vented or unvented gas logs? ›

Vented gas logs produce carbon monoxide emissions so your fireplace must have a chimney or flue. Ventless logs do not put off these emissions so no chimney or flue is needed, and the heat is more likely to stay in your space. Each type of fireplace requires its own type of gas logs to function safely and correctly.

Can you put a TV over a ventless gas fireplace? ›

In most cases, you should not install electronics above wood-burning stoves or gas fireplaces and inserts because they produce massive amounts of heat. That heat could severely damage your tv or other electronic devices.

Are vented or unvented gas logs better? ›

Ventless gas logs are much more energy-efficient than vented logs. Ventless gas logs are one of the most energy-efficient options you have for your home. As we touched on earlier, ventless gas logs use 99% of the fuel burned and radiate heat back into the room where they're used.

Is a ventless gas fireplace worth it? ›

A ventless gas fireplace is one of the most energy-efficient fireplaces that closely mimics the look of a wood-burning fireplace—without producing smoke, ash, or soot. They are also more energy-efficient than vented fireplaces because no heat escapes up the flue, so you'll save money on your gas bill.

What are the pros and cons of ventless gas fireplaces? ›

Ventless Gas Fireplace Pros & Cons
Pros of Vent Free UnitsCons of Vent Free Units
Since ventless gas products require no vent or chimney, they cost less to install, compared to vented gas appliances.Since ventless gas logs exhaust into the home, there is an added risk over vented gas fireplaces.
6 more rows
Jul 2, 2019

Does a natural gas fireplace need to be vented? ›

Must Vent to the Outside

Vented gas fireplaces do require a way to vent to the outside. This venting could take place through an existing brick or masonry chimney, but you are not limited to just using an existing chimney to accomplish the necessary venting.

Do unvented gas fireplaces smell? ›

Ventless logs do in fact produce an unmistakable odor, some more so than others depending on the quality of the brand. There is no way of preventing this, it is simply the nature of burning gas in your home without exhausting the fumes up a chimney.

What is the healthiest fireplace? ›

Ethanol fireplaces really give you the best of all the worlds without any repercussions. Not only do they have a real flame (unlike electric fireplaces), they require no flues or vents (unlike gas fireplaces) and have zero emissions of toxic compounds (unlike wood burning fireplaces)!

What is the most efficient type of gas fireplace? ›

Generally, fireplaces with features such as Direct Vent Technology, a ceramic glass front, a secondary heat exchanger, circulating fans and an intermittent electronic ignition system are going to be the most efficient to operate.

Can you run a ventless gas fireplace all day? ›

Most manufacturers don't advise running a vent free gas fireplace for more than a few hours a day. Usually, that's not much of an issue, because you'll get hot in 20 minutes, and you'll probably be ready to turn it off.

Why do ventless fireplaces smell? ›

In a gas ventless fireplace, oxygen is provided by the air in your home. If that air contains impurities, those impurities are drawn in with the oxygen and can produce odors which are amplified by the flame.

Do ventless gas fireplaces give off heat? ›

This u-shaped design means ventless fireplaces can provide more heat since none of it is being vented outside. Integrated Safety Features: Many ventless gas fireplaces come with carbon monoxide detectors and oxygen sensors.

Is a ventless fireplace more efficient than furnace? ›

Usually it is more fuel efficient to have the fireplace on because it doesn't lose any heat traveling through ductwork, but that also means the heat is localized and won't warm the entirety of a large house. So if everyone is cozied up in one room it is often better to have the fireplace on.

How long does a ventless fireplace last? ›

Ideally, if you have vented gas logs, you can expect them to last for more than 10 years. Ventless gas logs, on the other hand, have a lifespan of 3 to 5 years.

Are ventless gas fireplaces legal in California? ›

Vent-free gas appliances are prohibited statewide. If installing a vented fireplace in a bedroom or bathroom the fireplace must adhere to the following guideline: The room volume shall be not less than 50 cubic feet per 1000 Btu/hr.

Does a ventless heater give off carbon monoxide? ›

When properly maintained and adjusted, gas heaters produce low amounts of carbon monoxide. One cause of carbon monoxide poisoning from unvented heaters– incomplete combustion caused by lack of air–has been virtually eliminated in newer heaters by use of Oxygen Depletion Sensors (ODS).

How do you know if your gas fireplace needs to be vented? ›

A vented fireplace has attractive yellow and orange flames that lick upward around the sides of the ceramic logs. An unvented fireplace, by contrast, has much less striking flames. These flames tend to be smaller and bluer. As a result, an unvented gas fireplace won't create quite the same illusion as a vented one.

How long do ventless gas logs last? ›

Q: How long do gas logs last? A: In the average home, a well-maintained vented log set with ceramic logs will last 10 or more years. A well-maintained vent-free log set with ceramic logs can also last a long time, but, if heavily used, will begin to wear in 3-5 years.

Will ventless gas logs heat a room? ›

Ventless gas logs are extremely efficient and will provide an exceptional amount of heat for your room. They don't require a chimney or venting, allowing all of the heat produced to circulate back into the room, rather than escaping up the chimney. Ventless gas logs are designed to achieve a clean, smokeless flame.

Are ventless fireplaces legal in Wisconsin? ›

A: Per Wisconsin law, vent-free or ventless gas fireplaces can only be installed in homes built prior to 1980. While the safety of ventless fireplaces is debated all ventless gas fireplaces come with oxygen depletion sensors and catalytic converters.

Do gas fireplaces affect indoor air quality? ›

But to keep your home comfortable all winter long, it's important to consider how your gas fireplace might be affecting your home's Indoor Air Quality. Gas fireplaces release dangerous pollutants into the air, like carbon monoxide, nitrogen dioxide, and other particles.

Can you put a ventless fireplace anywhere? ›

“While traditional fireplaces can only be located in rooms with a flue, ventless fireplaces can be installed in virtually any room,” Galinsky says. Their location can vary, but their flames will remain static.

Can you vent a gas fireplace from an interior wall? ›

But what if that perfect spot for a fireplace is on an interior wall? No problem! Power Venting technology makes it possible by simply pulling outside air to the fireplace, while exhausting the fire's byproducts to the outdoors through the venting system.

Do you need a chimney liner for ventless gas logs? ›

Whether you go from gas to wood burning or vice versa, you must install a new chimney liner appropriate for that type of fuel and use. The same rule applies to heating and hot water equipment because different materials are more suited for different types of fuel.

Are ventless gas heaters legal? ›

These are commonly sold at hardware and home-improvement stores. These unvented (or vent-less) heaters are prohibited in most occupancies by the state fire or mechanical codes. This includes only heaters with an open flame; it does not include electric space heaters (no open flame).

Are ventless fireplaces legal in Colorado? ›

A: Vent free gas fireplaces are illegal in the state of Colorado. In this application, an electric fireplace would be your best option.

Do ventless heaters produce carbon monoxide? ›

When properly maintained and adjusted, gas heaters produce low amounts of carbon monoxide. One cause of carbon monoxide poisoning from unvented heaters– incomplete combustion caused by lack of air–has been virtually eliminated in newer heaters by use of Oxygen Depletion Sensors (ODS).

Are gas fireplaces allowed in CA? ›

Vent-free gas appliances are prohibited statewide. If installing a vented fireplace in a bedroom or bathroom the fireplace must adhere to the following guideline: The room volume shall be not less than 50 cubic feet per 1000 Btu/hr.

Is California banning gas fireplaces? ›

The Golden State will ban the sale of all new natural gas-fired space heaters and water-heating appliances by 2030, under a proposal unanimously approved by the California Air Resources Board on Thursday.

Do natural gas fireplaces need to be vented? ›

Must Vent to the Outside

Vented gas fireplaces do require a way to vent to the outside. This venting could take place through an existing brick or masonry chimney, but you are not limited to just using an existing chimney to accomplish the necessary venting.

What is code for a gas fireplace? ›

NFPA 211 is the Standard for Chimneys, Fireplaces, Vents, and Solid Fuel-Burning Appliances and NFPA 54 is the national fuel gas code which includes sections specifically pertaining to gas fireplaces.

Why don't they use gas stoves in California? ›

The USCPSC argued that the stoves emit air pollutants that are tied to respiratory illness, cardiovascular problems, cancer, and other health conditions, reports from the American Chemical Society and Institute for Policy Integrity.

Are vent free gas fireplaces legal in Massachusetts? ›

In Massachusetts, there are limits on where you can install vent free gas fireplace devices. These limits include: There must be a primary source of heat already in that room (baseboard or ductwork) Gas fireplaces cannot be installed in a bedroom or bathroom.

What will replace gas fires in 2025? ›

The new legislation on boilers that has attracted some big news headlines is that there will be no new gas boilers after 2025 - in newly built homes. So, all new homes built after 2025 will have an alternative heating system, such as heat pumps for example.

Why would California ban natural gas furnaces? ›

The ban, which was unanimously voted on by the California Air Resources Board (CARB), directs agencies to create a draft rule which will be put to another vote in 2025. The move was introduced to help wean Californians off of natural gas, transition to more renewable energy, and meet federal ozone standards.

Will gas furnaces be phased out? ›

In its ongoing effort to slash ozone pollution, the California Air Resources Board (CARB) voted Thursday to ban the sale of new gas furnaces and water heaters beginning in 2030. Homes will be required to install zero-emissions alternatives, like electric heaters.

Can you convert a ventless gas fireplace to vented? ›

Answer: Unfortunately, there is no way to convert a ventless fireplace into a vented fireplace. Ventless fireplaces are not designed to have a vent added to them. Your only alternative is to tear out the existing ventless fireplace and replace it with a vented fireplace.

Do ventless gas fireplaces need to be cleaned? ›

Your vent-free gas fireplace must be cleaned and serviced a minimum of once per year. Prior to the burning season, and additional cleaning in the middle of the season is recommended if the appliance is used heavily or it is located in an area of heavy traffic, dust, dirt, or pet hair.

Why does my ventless gas fireplace smell like kerosene? ›

A vent-free appliance requires room air to operate and when the appliance draws room air in with any chemical base odor it will go through the burner and come out smelling like a petroleum based product. Most chemicals that are airborne in the room that go through the burner comes out smelling like kerosene.


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