Ventless gas heaters -- my experience

[Existential Angst]

. Awl --

Apropos of the ahr thread Gas vs. electric range, someone spoke favorably of ventless gas heaters.

Some time ago, it was complete news to me that "ventless gas" heaters even existed, as I thought it was safety no-no, and also being conditioned to vented Modine blowers -- not cheap, AND you need a stack. But after some reading, I thought I'd died and gone to heaven, regarding my shop heat problem, ie, freezing my ass off.

So I bought TWO, of the "radiant" type, with the ceramic ditty, a small and a large, plumbed gas to the shop, and BAM, from a heat pov, I was in seventh heaven. I need not have bought two, and could have easily gotten by with just the small one! Cheap, too, I think $119 and $79.

But.... BUT..... The air quality was atrocious!! You could FEEL the air in the back of your throat -- and I spent many a youthful winter huddled in a gas-heated kitchen, with no such sensation. A little stuffy, mebbe, but nothing like this. Almost acrid.

Second, the water vapor.... holy shit..... I don't think a dehumidifier coulda kept up with the vapor, and the wall above the unit was just soaked -- not good metal, machinery-wise, OR wall-wise..

They lasted a month, and have been in plastic wrap for years now.

Never could figger out what that smell/sensation was, as they seemed to be burning clean, altho I never did bring down the CO detector. But I'm sure had those sensations been related to CO, I'da blacked out or wound up with a CO migraine.

Too bad, cuz the heat was ossum. In a sense, the poor air quality mighta been a blessing, cuz I proly woulda endured the prodigious water vapor, to the long-term detriment of the shop.

Now, I've added lotsa lighting, proly almost 2 kW worth, so THAT helps in the winter. That, and a long electric baseboard heater (with a 3 way wall switch, you can get high heat and a nice low heat, by switching 120 V to it), the dehumidifer, and the machines themselves keep it OK -- not toasty, like the ventless gas, but OK. A second portable electric heater helps in the super-cold. Also calisthenics.... LOL

[Frank]

I could not find the specific impurities from a vent-less heater but did clip from an OSHA bulletin on air impurities. I experienced these heaters in a friends hunting camp when he installed them after getting free gas from a gas well on his property. Can't remember any breathing difficulty but don't like breathing combustion products and don't like depending on the carbon monoxide and low oxygen safety features. Lot of the chemicals listed below could be present.

MAJOR INDOOR AIR CONTAMINANTS.

General. Although asbestos and radon have been listed below, acute health effects are not associated with these contaminants. These have been included due to recent concerns about their health effects. The investigator should be aware that there may be other health effects in addition to those listed.

Acetic Acid. Sources: X-ray development equipment, silicone caulking compounds.

Acute health effects: Eye, respiratory and mucous membrane irritation.

Carbon Dioxide. Sources: Unvented gas and kerosene appliances, improperly vented devices, processes or operations which produce combustion products, human respiration.

Acute health effects: Difficulty concentrating, drowsiness, increased respiration rate.

Carbon Monoxide. Sources: Tobacco smoke, fossil-fuel engine exhausts, improperly vented fossil-fuel appliances.

Acute health effects: Dizziness, headache, nausea, cyanosis, cardiovascular effects, and death.

Formaldehyde. Sources: Off-gassing from urea formaldehyde foam insulation, plywood, particle board, and paneling; carpeting and fabric; glues and adhesives; and combustion products including tobacco smoke.

Acute health effects: Hypersensitive or allergic reactions; skin rashes; eye, respiratory and mucous membrane irritation; odor annoyance.

Nitrogen Oxides. Sources: Combustion products from gas furnaces and appliances; tobacco smoke, welding, and gas- and diesel-engine exhausts.

Acute health effects: Eye, respiratory and mucous membrane irritation.

Ozone. Sources: Copy machines, electrostatic air cleaners, electrical arcing, smog.

Acute health effects: Eye, respiratory tract, mucous membrane irritation; aggravation of chronic respiratory diseases.

Radon. Sources: Ground beneath buildings, building materials, and groundwater.

Acute health effects: No acute health effects are known but chronic exposure may lead to increased risk of lung cancer from alpha radiation.

Volatile Organic Compounds (VOC's). Volatile organic compounds include trichloroethylene, benzene, toluene, methyl ethyl ketone, alcohols, methacrylates, acrolein, polycyclic aromatic hydrocarbons, and pesticides.

Sources: Paints, cleaning compounds, moth-balls, glues, photocopiers, "spirit" duplicators, signature machines, silicone caulking materials, insecticides, herbicides, combustion products, asphalt, gasoline vapors, tobacco smoke, dried out floor drains, cosmetics and other personal products.

Acute health effects: Nausea; dizziness; eye, respiratory tract, and mucous membrane irritation; headache; fatigue.

Miscellaneous Inorganic Gases. Includes ammonia, hydrogen sulfide, sulfur dioxide.

Sources: Microfilm equipment, window cleaners, acid drain cleaners, combustion products, tobacco smoke, blue-print equipment.

Acute health effects: Eye, respiratory tract, mucous membrane irritation; aggravation of chronic respiratory diseases.

[clare]

I'd be guessing, but possibly oxides of Nitrogen? )(NOX)

[Existential Angst]

Seems possible, but then why not from a stove top, oven? Also all the other listed agents from Frank?

Poss answer: the ceramic is acting like some catalyst, producing NOx compounds, or others? Or, the ceramic itself is outgassing/reacting in some way.

You can even smell nichrome wire or other type electric heater elements. Not all, but some.

AND, in my case, the shop volume to btu ratio, and the draftiness, could not have contributed to an undue concentration of these airborne chemicals from a pure buildup pov, so the agents must have been potent in themselves (at least throat-wise), and/or the heater was producing prodigious amounts of them.

[BobH]

I use a propane "Mr Heater" in the winter and have for 15 years. The moisture is noticable, but there don't seem to be any other problems. I don't use it for 8 hours a day, so maybe that's it. I worry more about the fire/burn problems than the air problems.

A friend used to use a kerosene torpedo heater in his shop/living quarters and it was wicked. In the winter, half an hour in there would give me a ringing headache.

BobH

[ChairMan]

Don't know what part of the country you're in but try to find a Dearborn heater. Used them for years and never had the issues you speak of

[Ignoramus2201]

I hate those filthy m.f.

i

[Steve W.]

The taste was likely due to the Butane that they add for winter use of propane. If it tasted sort of like weak weld smoke then it would be the butane reacting with the catalyst.

[Jim Elbrecht]

-snip-

I'd say all of that- plus the amount of gas you're burning in the shop vs your stove.

If it was producing enough water vapor to be a problem, you must have been burning a crap-load of gas. I have a ventless in a family room. There are 6 windows [double pane but no storms] there that never fog up unless I boil 2 pots of pasta on the stove in the adjacent kitchen.

I never smell anything. It has some sort of fake log, but it isn't part of the 'heater' it is just for show. All the heat is from the flames.

The CO detector is 4 feet from the stove. Only time it has gone off is when my wife wears a certain kind of powder-- and if I have all burners on the stove going and the oven.

I had a digital one that registered the 'highest level reached' for a while. It never got close to tripping unless one of the above circumstances occurred.

I love mine- Jim

[Existential Angst]

Well, this was on natural gas. But, altho it has been some time, "weak weld smoke" might characterize it, altho I kind of like welding fumes. :) I But what catalyst are you referring to? I was speculating that the ceramic *might* be acting as a catalyst, but do you know this for sure??

[willshak]

I have a vent less propane fireplace in my 4 Seasons' sunroom. When I lit it up for the first time after installation, it stunk to high heaven. I thought I had made a bad decision, but after using it a few more times, the smell seemed to get less and less each time. It turned out to be the heating of the fireplace's new interior parts materials that were giving off the fumes. Since then, the smell disappeared and it hasn't stunk since.

[Stormin Mormon]

Residential furnaces, are made with some kind of protectant on the heat exchanger. On the first heat, they pump out a lot of stink and fumes. Having installed furnaces for six years, I'd ought to remembered that.

[Larry W]

Did you by some chance have a tom cat in your shop? I can tell you from personal experience that if one decides that such a heater is some territory that must be marked, it will create all the symptoms you described.

[Steve W.]

The "ceramic" is actually a metalized item that uses a catalytic reaction to reduce the CO and convert more of the combustion gases into heat. The taste is still likely trace butane in the mix. It gets added to help the lower gases ignite easier when it's cold.

[Existential Angst]

Well, NG is methane, don't think they put butane in there, but there is some sulfurized hydrocarbon in there, so you can detect gas leaks.

That ceramic must be the problem, then, at least in my cheapie units -- forgot the brand, but I think most proly heard of them.

[Steve W.]

NG is usually about 85-95% methane. The rest is Iso-butane, Pentane, Hexanes, Hydrogen, Ethane, Propane. Plus traces of Nitrogen, CO2 and O2.

You could test this out by hooking a propane tank up to one and seeing if the problem is still there. Also you did make sure that they were set up for NG? Many of them are set up for propane.

[The Daring Dufas]

On some of that stuff, I seem to recall a threaded plug you have to remove, flip over and reinstall depending on the fuel source. It's on the regulator section of the gas control valve. It should be marked "LP" or "NG" and could look like a small pipe plug or a disk depending on the manufacturer. Any odd odor could be because of an incorrect fuel/air mix?

TDD

[Michael A. Terrell]

Gunner, you know better than to let ANY liberal into your shop. :)

[Mr. Austerity]

Whatever is in the air in the shop goes through the heater and is "burned", but with plenty of combustion air you should get only CO2 and water from the heater. A cold room being brought up to temp will condense the water vapor so yes the walls and everything else will get damp until the all is up to normal temp. I use ventless nat gas heaters and they work great for me. The water vapor problem isn't enough to keep static electricity down on dry days. and natural gas is sooooooo cheap,

[trader4]

Having only installed my own recently, I wish they would tell you that in the manual! I fired up the

120K BTU mother and it filled the house with light smoke. I suspected it was something in there as part of the manufacturing process and that it was normal, but not knowing for sure, you start to wonder if you dropped a tool with a plastic handle or something in there.