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I recently was in a wood stove distributors shop and he showed me some gas stoves which did not required venting via flues, etc. He said is was 99.9% efficient and had a catalytic converter in it which re-burned the CO gas. This made it very efficent and did not reequire it to be vented.
I was intrigued and considered putting one in my basement/clubroom to take the chill off. However, later I read in Consumer Reports about similar stoves (not the exact same brands) which made the same claims, but under their test did emit CO gas. Consumer Reports suggested leaving a window open a crack. That seems counter productive to me.
Does anyone have any info concerning these stoves?
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The testing for these decorative stoves assumes that they will not be used for periods exceeding 4 hours at a time, and that there is a reasonable amount of natural ventilation in the space.
Even though these unvented units have recently been legalized in California, I wouldn't use one for heating. Its too much like a bird sh**ing in its own nest. Any fuel burning appliance burns oxygen and generates carbon dioxide and water even if it burns perfectly efficiently.
I'd rather not wake up with a headache or dead, or have have the same happen to one of my architectural clients. Use an exhaust flue!
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I tend to agree for the reasons cited plus ventless stoves add a significant amount of moisture to the living area.
Direct vent is a compromise where you can vent directly outdoors. The flu system is duel wall and therefore draws outside air for combustion. They are not energy efficient by any means but do a good job of warming a large area as a supplemental heat source.
*Gene Leger pointed me to a good article on the dangers of vent-free fireplaces:"Vent-Free Gas Heaters--How Safe?" in July 1997 issue of Journal of Light Construction.Something missing from that article was the result of combusting (oxidizing) the contaminants contained in natural gas & LPG. Sulfur compounds is the most common and sulfuric acid is a byproduct.I have read many advocates of vent-free firelaces, that also advise you to never vent a gas dryer in the house due to dangerous fumes (and excess moisture), GO FIGURE. Even the Roman engineers learned the best place for by products of combustion is outside of the habitable envelope. That's where the termi plenum originated.Go with the direct ventcheers; JohnE
*Jim, To the best of my knowledge you can't reburn any complete products of combustion but rather burn left over products of incomplete combustion through the use of a catalytic converter. These appliances are a perfect example of abuse and ignorance of safe and responsible design of products for consumer use. When CO and interior pollution problems had become serious enough to warrant measures to prevent and remedy such conditions, acceptable levels of polluants had to be established. These appliances under strict testing measures (hopefully) are desinged to omit an acceptable level of poisionious gases. The target consumer, one that's willing to trade a couple of hundred bucks over a vented appliance for common sense and safety. Aside from the sales baloney of efficency and economics, you can rest comfortably that if you follow safe operating proceedures ( which include opening a window), you are also protected by an oxygen depletion device(how bout that). Gary, Ed and John I'm with you guys and Jim I hope got what you came here for. Good Luck, Keith
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What decided it for us was how ill we felt after visiting the store! Yes, the catalytic converted is designed to complete "burning" (i.e., oxidizing) CO and other substances that still have some energy to release. It is because these pollutants are still highly chemically reactive that they are so dangerous -- they'll bind to hemoglobin to the exclusion of oxygen, etc. You don't recover from mild carbon monoxide poisoning until the blood cells are replaced, so chronic exposure would be particularly worrisome.
Get a CO detector if you have gas appliances and skip the "vent-free". Don't put your lives in the hands of an oxygen sensor, which may not work and which will ignore the buildup of other poisons. Admittedly, direct vent without an existing flue costs a lot more because of the labor involved ... but there are other ways to produce heat.
*Ed - I think my direct vent is listed as 80% efficient - new model 3 or 4 years ago - and I thought newer ones were even more efficient. Please help - is this not efficient, is the claim bogus, and what would you consider efficient? (I put it in an addition and thought it was more "efficient" than adding a radiator to the existing hot water sysem.)
*One further note. My brother got a ventless gas stove after we had used a wood burning stove for years. With wood fire burning being more and more regulated we thought about the gas ventless unit. Oops! My wife operates a home day care and we found the the state specifically prohibits the use of any ventless heating device. If vented is good for the little tykes its good enough for me. (time out--got to haul in some more wood so we can have a nice toasty house to watch the Broncos win the SuperBowl--again.) Thor
*New MasterCard commercial:Flight to Miami: $650Tickets to the Super Bowl: $2,000Two hot dogs and two beers: $50Game Program: $20Seeing the Dirty Bird dance in the Superdome: Priceless
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Bill,
I have a Hearthstone cast iron stove and frankly I don't know what the efficiency rating is. Will have to check it when I get home, am on the road now. A lot of the heat goes out the side of the house, there is no heat exchanger. It is radiant device (could add blower, chose not to) that throws a ton of heat and we like it a lot. Looks good and we are satisfied, will check into the rating.
Take care, ED
*I tried a ventless heater on my 3 season room. Took it out the same week I installed it. It created so much water vapor (by-product of combustion) that I could not see out the windows. Besides not being able to look out, all that condensation would have run down onto the window sill with no place to go and could have caused damage to the wood. I went the extra trouble to install a stove with a conventional stack and I'm very pleased, now.Mike
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I recently was in a wood stove distributors shop and he showed me some gas stoves which did not required venting via flues, etc. He said is was 99.9% efficient and had a catalytic converter in it which re-burned the CO gas. This made it very efficent and did not reequire it to be vented.
I was intrigued and considered putting one in my basement/clubroom to take the chill off. However, later I read in Consumer Reports about similar stoves (not the exact same brands) which made the same claims, but under their test did emit CO gas. Consumer Reports suggested leaving a window open a crack. That seems counter productive to me.
Does anyone have any info concerning these stoves?