Ventless Fireplace

Recently came across the following situation: Whenever the ventless fireplace is in use the smoke detector alarms. It is not a combination CO/Smoke detector.

Has anyone else experienced this? Is there a remedy?


Put in a proper approved Fire Place . These are not allowed in many places .
Roy Cooke

My smoke alarm goes off when my woodstove hasn’t been used in awhile…

When it was brand new the smoke alarm went off right away if I got too hot a fire in it too fast…the manufacturer (lopi) said it was a combination of the oils/paints used on the metal…

Could this be the prob? Is it new?

There are “approved” units and they are “allowed” in many places.:wink:

If you leave the window open.

It might be many things, but here is some information on smoke alarms that might help you figure it out:

There are three basic types of residential smoke detectors, all with different means for detecting smoke and fire, different types of fires they detect best.

Ionization Smoke Detectors powered by batteries are the most common kind and economically available at most local hardware and discount stores. They can be mounted easily in just about any location. They use a small radioactive source (not harmful to humans) to cause the air inside the detector to be capable of carrying electric current.
As particles of smoke enter the detector they block the flow of electricity. Low electrical current causes the alarm to sound. These detectors work best on flaming type fires (wood, paper, etc) and react a little slower on smoldering fires (mattresses, couches, etc).

Photoelectric Smoke Detectors use a light sensitive photocell to detect smoke inside the detector. They usually require a connection to an electrical supply but are also available with a battery backup.
A light bulb puts out a beam of light. The photocell is hidden from direct exposure to the light beam. Smoke entering the detector causes the light beam to be reflected in several directions. The photo cell detects the reflected light and causes the alarm to go off. These detectors work best on smoldering fires and react a little slower on flaming type fires.

Thermal Detectors usually requiring a connection to an electrical supply, react to heat rather than smoke. A fire must raise the heat level near the detector to cause the alarm to go off. This type of detector is mostly used in dusty, dirty environments usually found in industrial and commercial applications. This is the type of detector that most fire sprinkler heads use to detect heat, pop, and start spraying water. This detector would be good near a cooking stove where an ionization or photoelectric smoke detector might cause false alarms.

I hope this helps somewhat…

That’s only true for unusually “tight” construction. As always follow the manufacturer’s instructions especially with respect to safety.

I agree. I have seen several ventless fireplace units operate with no defect or need for open windows. The installation of a cabon monoxide detector is always recommended, and definitely so in the case of the ventless fireplace (as an additional precaution) but every source I find indicates that they are more efficient and create less CO than a standard vented gas unit.

Case in point - this is from “ask teh builder” but matches what I have seen from several other sources…

"Years ago, there was only one type of gas log, that being the vented type. These are still made today. However, energy conservation trends produced gas appliances that are vent free. This technology found its way into the U.S. gas log market not too long ago. The technology actually started in Europe many years ago.

The vented logs are those that require a working chimney. They produce vast amounts of heat (some up to 90,000 BTU’s per hour.) But, since you must open the fireplace damper as if burning a wood fire, most of this heat escapes up the chimney (85 to 90 percent!)

Vented gas logs also produce massive amounts of carbon monoxide, a deadly, toxic gas. This carbon monoxide results from the low tech burner that is used to combust the gas. In most cases the gas simply escapes from a simple pipe that has holes drilled into it. This pipe is usually covered with silica sand. The gas filters through the sand so that the entire area under the gas log set appears to be on fire.

Vent free gas logs are entirely different. They have specially designed burners that are not covered with anything. They are hidden underneath and behind the logs. These burners are adjusted so that enough air is supplied to the burner to combust the natural gas with top efficiency. This combustion process produces a minimum of carbon monoxide.

Furthermore, as an additional safety measure, to protect against the buildup of carbon monoxide in a confined space, vent free logs approved by the American Gas Association (AGA) are equipped with oxygen depletion sensors (ODS). These sensors can tell how much oxygen is left in the air near the bottom of your floor. As carbon monoxide starts to build up, it dilutes/depletes the amount of oxygen in the room(s) / confined space. This, in turn, activates the sensor and the gas shuts off to the logs. All of this happens long before you would feel the effects of carbon monoxide poisoning.
Because you cannot cover the burners of vent free logs with anything, you cannot experience the burning ember effect with these products. These logs are not as realistic as the vented gas logs. "

Still not legal in Canada or New York city.
I understand there are many places in the USA that do not like them .
Never in my home .
Please read just afew who agree they are not a good idea.
Roy Cooke…

Roy, I know you have strong feelings about this type of device but your links seem to be personal rantings or the opinions of those with a vested interest in disallowing these types.
Can you produce one documented case of injury from these devices? Anecdotal stories don’t count BTW.:wink:

Many of these article end with something like-You have to decide for yourself.

Gee you mean you want to know some one has died before you will agree they are not safe .

When Canada and New Your City and many towns in the USA and countries in the world will not approve them .
This gets my attention .
The other side of you argument is the only ones who say they are safe are the manufactures and those who sell them .
The Gas company will not
(To: The U.S. Consumer Product Safety Commission. RE: Unvented Gas Fireplaces
Jun 19 '02

The Bottom Line The Gas Appliance Manufacturer’s Association, (GAMA) have refused to produce proof that unvented gas fireplaces are safe, because they know,… they are not safe. They simply sell well. )
Sorry I guess we will have to agree to disagree.
Roy Cooke

Read that carefully.Its one of those rant things I mentioned.:wink: This guy has a personal compaint regarding these products. He’s offering his “opinion” in the form of a rant against their approval, not facts.

Facts are stubborn things. Let’s have some.

"vent free logs approved by the American Gas Association (AGA) are equipped with oxygen depletion sensors (ODS). "

Seems the American Gas Association thinks they are ok - they don’t have as vested interest in vented versus unvented as far as I can tell…

The NYC thing would probably more likely be linked to the age and heights of many buildings, population density and the inability to alter existing structures to accomodate where necessary which would lead to many homeowner installations that are not correct.

Also, check out info from the Vent-Free Gas Products Alliance (a coalition of members of the Vent-Free Gas Products division of GAMA)…they seem pretty enthusiastic about vent free gas fireplaces:

Finally - there’s this (from the following site: ) which seems to indicate that GAMA has conducted the study and offered the requested proof:

gee they all sound to me to be associated with GAS.
Consumer reports says no way.
Try and get some one who is not associated with GAS to say they are safe.
Could it be money talks.
All over the world they say no way.
Those things are no different then a BBQ and we all know you do not want to heat with a BBQ.
Logic comes to the front for some things.
Burn up the oxygen in the home and you die .
Why do you think they say open the window .
I would not keep a kettle boiling adding moisture to you home non stop why would I have a BBQ burning in my home adding Moisture non stop.
As I said in my last post I guess we will have to agree to disagree.

For free I would not have one .
Roy Cooke

So can someone please explain to me the difference between gas stoves that are more common in a home and an unvented gas fireplace? Lets use that as a point of comparison.

My daughter has one in her home (an unvented fireplace) in Michigan that was installed by the local gas company. It was installed by their licensed installer that also is an inspector for the company. - Interesting!

Yes Gas stoves usually have a hood vented to the out side and who would have a gas stove on full blast for 8 hours…
Many people think Gas stoves burn clean and they are tested to prove they do .
When you put on a cold pot they now are burning bad and adding the not so nice stuff to the home .
Food for thought those with gas testers might get some surprises if the do some testing over the cook stove .

Roy Cooke … RHI… CHI… CMI…



Next you’ll be telling us not to use candles in the home.
BTW-Candles actually are much more dangerous than vent free fireplaces. And yes there are facts to back that statment up.

WOW! you can not be any more obvious .
Will you please tell us the rest of the story .
What is you connection to the Gas industry.
I am sure it is plenty and you must have a long history to give us .
Thanks Roy Cooke



I have absolutely NO connection to the GAS industry. What on earth led you to that conclusion? My frustration with you has to do with your sharing your strong opinions with no substantiated facts ie. documented injury or death caused form the use of Ventless Fireplaces or heaters when used in accordance with the manufacturer’s instructions.

Have a good day Roy.

A NACHI main event is brewing…