Thread: Pre-fabricated ventless fireplaces

I know that the general consensus on these is that: they suck/ condemn them/ and tell everyone that they vent carbon monoxide into the living space.

Let's be realistic though, if present (usually townhomes/ commonwalls or condos when I see them) they will get used by the homeowner whether for romance or during a power outage.

Here's my questions:

1. I've heard that blower fans aren't allowed with them to help discourage from using them as a primary heat source, this one was pre-wired with a wall switch (next to the fireplace off/on switch). Am I mistaken on this??
2. Has anyone ever heard of electronics/ TV's/ or the like from getting damaged due to the excessive heat generated by these?
3. Won't a carbon monnoxide detector continuously go off when these are turned on?

I think the fact they're 100% efficient is great (sarcasm), but everytime I see them I scratch my head and mutter to myself what the heck where the manufacturer's of these thinking

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I would get a copy of the installation instructions to answer your questions. Do you have the make and model available? I would also check the clearances to that side wall.

Some manufacturers will sell whatever they can get away with - safety be damned. Anyway, just because a local ordinance allows something it is not necessarily an indicator of safety.

I dispute the term "ventless" which of course is widely used. These units do vent - into the living areas of the home. They generate high amounts of water vapor and consume oxygen. They have oxygen sensors to shut off the flame if poor air quality becomes present. As for the heat issue with electronics I have not heard of anything but that's not to say that it's not a concern. The burners in these units are different from the gas log units in the "vented" fireplaces and therefore CO is supposedly less of a concern - or so some would like you to believe. Where ventless units are allowed I think that all you can do is alert the client to the precautions that should be taken with these units.

I too question the clearance to the side wall in your photo.

I always tell clients to throw the thing in the alley the day of close. I try to say it when the realtor is standing there because I love to see their look of horror.
1 - I could swear I've seen a few of these with blowers but can't remember for sure. Wouldn't surprise me if there are some. Mostly not though I think.
2 - From my experience they don't seem to put out that much actual heat. I doubt they would harm any electronics
3 - They should but I can see how they might not. The CM detector usually isn't anywhere near the living room. The following is sheer guessing on my part: I'm guessing they put out a low, steady volume for only an hour or two, so it may not be enough to reach the detector in the basement or wherever. If the thing were on all day or the detector was in the living room I'm guessing it would go off.
I can smell the thing every time I walk into a unit where the listing agent as turned it on for that special ambiance.

I have seen some flat screen TV warranties say that will not cover damage from heat.

[quote=Markus Keller;155662]I always tell clients to throw the thing in the alley the day of close. I try to say it when the realtor is standing there because I love to see their look of horror.

(like)

Thanks for the feedback guys, I appreciate it.

As a UL listed appliance you have to go by the fireplace's Manufacturer's Instructions, since that is what it was tested for. If the Instructions state that a blower is a part of the unit, then it is.

Ventless gas logs are considered safe and are UL listed to be used in a residence. Although certainly not my favorite type of appliance, there is nothing particularly unsafe about them as long as the manufacturer's recommendations are followed and the unit is kept in good repair, as with any UL listed appliance.

As a Chimney Sweep, when I am asked about these by homeowners, my reccomendations are that they keep the instructions for the unit close and follow the instructions the manufacturer included and to always have a CO detector in the home.

If the homeowner doesn't have the instructions for their unit, I am glad to download them and provide a copy for a nominal fee, usually $5.

Chuck

Chuck, I don't know of anything that is *safe*. Safety is a relative term. Fireplaces are a lot safer when you don't burn fires in them. What you can say is that when installed in accordance with the mfrs listed instructions (does NOT have to be listed by UL but any recognized test lab) AND in accordance with the applicable building code, and operated within the mfrs instructions, they are considered an acceptable option.

It it is a circulating self contained VF firebox and logs that is listed for use with a convection blower then yes, as Chuck says, it is approved. Keep in mind ANY stray air currents can distort the flames causing impingement and thus incomplete combustion = CO, soot, aldehydes, NOx, odors, etc.

The Oxygen Deplention Sensor or ODS is merely a finely tuned safety pilot that drops out when the ambient O2 reaches about 18.5%. They also suffer nuisance dropout when the primary aeration port clogs with dust bunnies.

VF can produce a ton of heat. This is of concern for wall finishes as well as framing. If it is a built-in unit, it is absolutely critical clearances to combustibles are met. If it is installed into an existing woodburning fireplaces, it must first have a Level II inspection, make what repairs are required, then install a canopy or hood if needed per mfr, to protect clearances to a combustible mantel or trim. You also need to check the building code because there are very few instances where VF are even allowed due to building construction, air infiltration rates, makeup air, etc. The ANSI Z21.11.2 allows for wall surface temps. up to 117F above the ambient room temp. This would certainly ruin most any sensitive electronics, which usually cannot tolerate much above 103F.

The reason VF don't set off UL listed CO alarms is those alarms are junk. They have a very poor performance record and even if you get one working to spec., the listing precludes it from alarming at 70ppm for up to 4 hrs and 69ppm for up to 30 days.

We call them "lung vented". A new field study recently identified much higher NOx levels than first thought so they don't have to kill you to be bad.

The new energy rating programs from BPI and HERS call for the removal of all VF appliances as part of remediation.

I have never in my career found a single VF burner over one yr. old with the proper maintenance and did not stink. I have found them with dampers cracked to where the down or updraft was CAUSING increased CO production from flame cooling and impingement. I usually find them oversized for the space installed and against the building code requirements. I often find the occupants burning them as primary heat sources.

The safest form of ventfree is electric but even those are not *safe*.
HTH,

True, "safe" is a relative term.

They are, however, UL listed and approved for use in a residence, so they are not particularly "unsafe" when used and maintained in accordance with manufacturer's recommendations. there is no reason to tell a homeowner that they are any more inherently dangerous than other heat-producing appliances approved for use in a residence.

Chuck

I cringe whenever I see discussion about "vent-less" gas fireplaces/heaters. No such thing! I understand some states may allow these "vent-less" devices that actually vent their combustion gases into household air, but we here in Minnesota do not. Our state building code specifically calls out and excludes these so called vent-less heaters.

For what it's worth, there are some excellent energy efficient gas fireplaces for not a lot of money, and the "vent" can go out the back, side, or top of the unit. Super easy to install!

Yeah, I cannot say I'm a fan of them, but they are allowed in Georgia. In fact I see a lot of them in new homes where the is no chimney chase whatsoever! I had a customer call me to "clean her fireplace" and when I got there I discovered it was a ventless fireplace built-in directly under a bedroom (no chimney in the house at all) and she had been burning storm lamps inside the empty fireplace for effect and had soot everywhere.

I had to decline the job, of course and referred her to a shop that specializes in gas log fireplaces for more advice.

The builder had installed the ventless fireplace but no gas log set and there were no manufacturer's instructions anywhere.

chuck

I see a lot of these. If they are in operation I check for carbon monoxide, and usually (though not always) it is at or near 0. I do not light pilot lights; if it is not lit I do not check the unit. (Other than visual). I still always recommend the carbon monoxide detector, since the oxygen depletion shutoff is NOT the same thing (it's surprising how many people figure it is a substitute.) I also point out that it is venting to the room. I've seen at least two homes using them for the only heat source, which is a terrible idea. I'm prohibited by state law from quoting any codes, but I tell my clients it is simply unsafe to do and they need to budget for an honest-to-goodness furnace.

When the manufacturer recommends opening a window in the room while the unit is in operation....in winter time.....it doesn't make me think a ventless gas fireplace is a good idea.

Some of the manufactures also say not to operate the units for more than three hours at a time.

I just attach one of the warning labels (in picture form) to the report, so they can read about it themselves. Buyers never read those metal data plates under the firebox, so now they see what a dangerous device they can be for the occupants.

Even scarier is that they use vent-less propane heaters in RVs all the time.... that's just crazy IMO. Every reason they are dangerous in a house becomes exponentially worse when you're in a small box with one.

Hi, ALL &

As has been stated earlier - rely on U/L and /or CSA Testing confirmation on these things...

I NEVER have one on my own home, though - even if they offered one free (gives me the creeps just thinking of it being lit, indoors) !


CHEERS !