Comments on: A Ventless Gas Fireplace Is a Liability

By: John Proctor

John Proctor — Wed, 10 Sep 2014 20:54:50 +0000

Gas appliances vented into
Gas appliances vented into the occupied space are always a potential problem. Even if they don't "smell" they are still a problem. CO is an odorless, tasteless gas. These devices also produce NOx which is also a health hazard. If you can find the manufacturer's instructions for the house vented fireplace, you will probably find that they say you should open a window when you run the device and that it is "decorative" only. 4 to 6 hours is way, way, way too long.

By: kelly

kelly — Wed, 10 Sep 2014 18:56:07 +0000

Hi, I have a "unvented
Hi, I have a "unvented" fireplace. My question is if I take the logs out, is it safe to use for about 4-6 hours at a time? There is no smell with the logs taken out. Thank You

By: John Proctor

John Proctor — Thu, 19 Jun 2014 20:51:13 +0000

@Bradley

@Bradley
As best I know they are not convertible to venting. If your home had a real fireplace with c chimney, you can put in a vented gas fireplace.

By: Bradley Clark

Bradley Clark — Wed, 18 Jun 2014 21:25:30 +0000
We recently bought a house
We recently bought a house with a ventless gas fireplace. Since realising it's ventless I've been wondering what to do with it. Any ideas? Can you retrofit venting?

By: Chad

Chad — Sun, 01 Jun 2014 03:56:41 +0000
Use those data loggers to see
Use those data loggers to see the effect on humidity. Lady you dont want to have to run a dehumidifier. lOL

By: Jody Jones

Jody Jones — Fri, 29 Nov 2013 20:39:33 +0000
We recently turned ours on
We recently turned ours on and immediately realized the issues you point out. Who do we contact to replace in the Austin/central Texas area.

By: Judy Lester

Judy Lester — Wed, 18 Sep 2013 08:54:51 +0000
I see no empirical data in
I see no empirical data in this article, only anecdotal evidence. The story about the man with the head achy wife is a perfect example and reminds me of clients who call me crying that their computer crashed after installing a completely unrelated update.

If you are serious about steering people away from unvented fireplaces and heaters (and I assume you are), you have to lay off the unverifiable scare tactics and reliance on post hoc ergo propter hoc and start presenting hard data to support your claims. How about a study of a few dozen (or preferably hundreds) of various makes and models of unvented appliances (blue flame, radiant, fireplace), noting the BTU's of the unit, cubic feet and R-value of the room and the CO and CO2 measurements in fifteen minute increments over a period of, say, eight hours? Believe it or not such studies actually matter and anything less is just talk, regardless of the amount of education and experience the person doing the talking might have.

PS: I'll give you point regarding moisture because everyone knows that water vapor is a byproduct of fossil fuel combustion. However, that really is the least important issue since the advent of a nifty little appliance called the dehumidifier.

By: Allison Bailes

Allison Bailes — Tue, 05 Feb 2013 08:33:34 +0000
Bob: "
Bob: "Lung-vented" is a good term for them!

Don G.: Yeah, a vented pressure in a room with negative pressure is also room-vented.

Skye D.: Kudos to you. It's hard to refuse work, but I'd rather stand on principle and go broke than do things that I know are unsafe.

Robert T.: It looks like Skye And John Proctor addressed most of your questions. Renting a thermal imaging camera may be possible, but unless you've had training, it may not be helpful to you, and it could even give you misleading results.

John P.: I like the seatbelt story. I'll be using that one.

Nate A.: You're welcome, Nate. Please do write about it. We need to keep getting the word out.

Don W.: Yes, gas ranges--and even worse, gas ovens--need to have range hoods that are vented to the outside and used whenever the appliance is used. Here are a couple of articles related to that:

Don't Let the Turkey Get You Down! Carbon Monoxide alert

Recirculating Range Hoods — As Effective As Recirculating Toilets

Steve W.: Well, I sure hope Canadians are obsessed with heating, at least next week when I'll be in Toronto!

Jaap W.: Sounds like you have a good grasp of the potential problems.

John: I'm still waiting for an "argument that refutes this campaign against these devices." You flatter yourself if you think you can say something that will cause me to close comments here. I just get tired of responding to people who make themselves look like idiots who haven't even read what I wrote. Now, what was that you were saying about providing some kind of evidence?

By: John

John — Tue, 05 Feb 2013 05:57:15 +0000
Allison, if i post a fact
Allison, if i post a fact/experience-argument that refutes this campaign against these devices, will you close this blog too claiming that commenters with vested or commercial interests that do not align with yours have invaded the blog?

I have a quality ventless gas stove in my fireplace. Nearby are MSA CO sensors and one aircraft-grade 1ppm sensor that have never registered anything but zero. Yes, following certified calibration. Nothing like having good ole data.

Oh, I do not sell any of this stuff, including the services you-all do. I'm just one of those stupid consumers.

By: Jaap Weel

Jaap Weel — Sat, 26 Jan 2013 03:57:56 +0000
I'm sure if the manufacturers
I'm sure if the manufacturers haven't been sued into oblivion yet that apparently these things aren't quite as unsafe as they seem, but based on my intuition anything ventless that burns enough of anything containing carbon to considerably heat up a room seems like CO poisoning waiting to happen. I know that natural gas is among the cleanest burning of fossil fuels, but that's only true under optimal conditions: well designed, clean nozzles, etc. In practice, there's know-it-all contractors going beyond their core competency, there's homeowners who try to burn wood in these things and think of the gas supply as an easy way to get the wood to light on fire... I live in Northern California where many small houses and definitely apartments do not have central heat but instead small gas heaters, and as far as I've seen, even the smaller ones of those are always vented. So are gas water heaters. The biggest unvented gas burning appliance I've seen is an oven. If I bought a house with one of these, I'd want some pretty hard evidence that they were harmless, and some pretty solid CO detectors, before operating it.