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On a mail-list I sbscribe to, a neurologist has asked whether propane powered torpedo heaters could be the source of carbon monoxide for a patient of his whose a drywall hanger.
The answer is, of course, “they could be.”
I’m wondering if anyone here has used CO monitors on the jobsite when using torpedos and what your experiences have been.
Bob
Replies
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There definitely is. Could be a lot. That's a prety sloppy combustion process in terms of mixture control, eveness of fuel distibution, and ombustion time. Really efficient furnace have combustion times of 0.5 to 1.0 seconds. I'd be really interested in someone putting a CO detector with digital readout in an enclosed space with one. I've got the meter but not the torpedo heater. A no-brainer: DO NOT use any unvented heater in an enclosed space. If there's not a separate flue pipe going outside, there's CO, CO2, and unburned hydrocarbons in the air you're breathing. -David
*A detector was purchased recently after one guy complained of sensitivity to the fumes. It is digital but has always read zero. We run two torpedoes at the same time. But then we always have a window open. This proves some people are sensitive to even tiny amounts of carbon monoxide.
*S Edwards, if the CO levels were low, I would be surprised if your employee was reacting directly to carbon monoxide as everything that I have read on the subject indicates that it is " an invisible, odorless, colorless gas created when fossil fuels (such as gasoline, wood, coal, propane, oil and methane) burn incompletely." One of the primary problems with CO is that people don't react to it until it collects in the bloodstream to create a degree of toxicity. (Disclaimer: I am not an MD and I haven't even played doctor for several years...) Most likely unless he shows the symptoms below, he is reacting to some other component of the combustion process:Concentration (parts per million) Symptoms 35 No adverse effects within 8 hours. 200 Mild headache after 2-3 hours of exposure. 400 Headache and nausea after 1-2 hours. 800 Headache, nausea and dizziness after 45 minutes; collapse after 2 hours. 1000 Loss of consciousness after 1 hour. 1600 Headache, nausea and dizziness after 20 minutes; unconsciousness after 30 minutes. 3200 Headache, nausea and dizziness after 5-10 minutes; unconsciousness after 30 minutes. 12,800 Immediate physiological effects; unconsciousness and danger of death after 1-3 minutes. Source: U.S. Consumer Product Safety Commission In severe CO poisoning, COHgb [hemoglobin carbon monoxide] levels are usually more that 30-50% and the findings include intense headaches, visual field defects, subtle confusion progressing to coma, seizures, papilledema, retinal hemorrhages, angina, ventricular arrhythmias, and death. Symptoms of CO poisoning are vague and mimic other disease states. Some random quotes on carbon monixide poisoning: Deaths from unintentional carbon monoxide poisoning - about 700 in 1993, according to the National Safety Council - are fairly rare. Three of every five of these deaths typically involve vehicles, one of every five typically involves heating or cooking equipment, and the other one of every five typically involves other or unspecified causes.* According to the NFPA, there were 242 CO-related non-fire deaths attributed to heating and cooking equipment in 1991.** The leading specific types of equipment were: Gas-fueled space heaters (69 deaths) Gas-fueled furnaces (52 deaths) Charcoal grills (36 deaths) Gas-fueled ranges (23 deaths) Portable kerosene heaters (23 deaths) Wood stoves (13 deaths) As with fire deaths, the risk of unintentional CO death is highest for the very young (ages 4 or younger) or the very old(ages 75 or above). There is a fairly long list of links on carbon monoxide at:http://www.pp.okstate.edu/ehs/links/co.htmBe aware that even though a combustion process that is complete and produces no carbon monoxide can still theoretically kill you through producing enough carbon dioxide to suffocate you. While I have never heard of this happening (I assume that when the CO2 level started to build up, CO would be produced and that would kill you instead...) OHSA has issued a warning on C02:A potential asphyxiation hazard exists when carbon dioxide is dispensed from tank cars (rail cars),cargo tanks (tank trucks and trailers), and portable containers to stationary, low pressure, carbon dioxide supply systems at consumer sites. These systems are used for supplying carbon dioxide gas at beverage dispensing sites, greenhouses, welding fabricators, and in other applications. Highconcentrations of CO(2), which displaces oxygen, can result in death in less than 15 minutes.When I lived near Concord, CA, several boys suffocated when they went into an abandoned coal mine where CO2 had collected. There used to also be periodic suffocations among workers who cleaned out petroleum storage tanks and other containers, although I don't know what the gases involved there were.
*CaseyR:NO!!! (AND YES, I'M SHOUTING)Those levels are for so-called "normal, healthy adults" are were established pre-WWII. Many people are far more sensitive to CO than those figures would indicate.In addition, chronic expsoure to low levels of CO are now believed to cause significant adverse health effects.Under the current UL standards, CO detectors with LED readouts are not supposed to register below 30ppm, so a "0" reading doesn't mean "0"The best Web source for medical info on CO is at http://www.phymac.med.wayne.edu/FacultyProfile/penney/COHQ/co1.htmWithin the CO community, there are many who consider the UL standards and CPSC figures a cruel hoax.Bob
*S Edwards:Please refer your guy to http://www.phymac.med.wayne.edu/FacultyProfile/penney/COHQ/co1.htmIf he is sensitive, chronic exposure to low levels can destroy the quality of his life. Oxygen treatments are believed by many to be beneficial (especially hyperbaric) although this is not "proven."Do NOT rely on the consumer CO detector, they are not accurate and do not reveal low levels. An open window is NOT necessarily sufficient.Try to have the site tested by a Building Performance Institute certfied Carbon Monoxide Analyst, or at least someone with a professional digital readout carbon monoxide meter such as the Bachrach Monoxor II. Please feel free to contact me at [email protected] with any questions. If you're anywhere near NW Ohio, I will test for free where CO poisoning is suspected.Be aware that the medical community often mis-diagnoses CO poisoning.This isn't just a matter of life or death, it's a matter of able or disabled.Please see also my other message.Bob Walker
*Bob: Had a thought about this while lying in bed last night. Is there carbon soot inside the torpedo heater? If there is, it is burning rich enough (at times, at places in the flame) to produce carbon and is definitely producing CO. Rich flames make the most CO. Lean flames produce less C and CO because of the excess O2 but produce more NOX because of the high temperatures. If there is no soot, you don't know anything."Many people are far more sensitive to CO than those figures would indicate." Quite true. And the largest class of such people is smokers because they already have some CO in there blood. On average, they are more sensitive to CO, high altitude, and unpressurized planes.Casey: Thanks for the info. Follow up on your caving and petroleum tank thoughts: It is hard to succumb to CO2 without noticing because you have a very strong suffocating feeling and a need to breath. I'm a caver and know a lot of people who have researched 5% CO2 caves. Personally, I turn around when the Bic lighter no longer lights. But if you don't keep checking, you can get a lot of CO2 into your body and yet still have a long ways to get back to the surface, perhaps too long.Those tank fatalities in your area might have been at one of the local refineries. I worked at the Cehvron refinery in Richmond for a few years and they showed films on H2S dangers because of fatalities at other, local refineries. While H2S really stinks at low concentrations, at high concentrations there is olfactory overload, you don't smell it, and quickly succumb.
*David,Good points. Another important point is that, contrary to common understanding, you b cannot tell how clean a flame is burning by the color; you know, the old "yellow flames mean CO, blue flames are clean."The leading authority on CO testing, Jim Davis, says it isn't true and my field experience has found many textbook blue flames producing significant CO (in furnaces and boilers.)On soot: whenever I see carbon deposits on gas logs during home inspections, I pull out the Monoxor II and test. Usually, there's significant CO, but there have been enough times that they're burning clean that I'm starting to wonder. I do not have enough info, though, to draw any conclusions.Bob
*Bob: Where can one purchase a carbon monoxide detector that displays all levels? Conditions change day to day on the job site as heaters are moved and one takes advantage of available doors or windows. I purchased the top of line detector available at HD. If it is not accurate then why does HD sell these things? Next week I am working in a crawl space with NO available ventilation except for the access opening. Next to the heater I am operating a high volume fan to create air movement. Am installing radiant floor tubing and the connectors sometimes fail in cold temperatures so I do not have a chioce. One of the other guys works by himself and he too is wondering about the effectiveness of his sensor.
*S Edwards: Bob's right, UL revised its UL 2034 specification (published in 1998, but implementation was delayed until January 1, 2000). For a CO detector to be UL-approved for residential use after that date, UL requires that it must not indicate CO levels less than 30 parts per million (PPM), nor alarm at levels below 100 PPM. This requirement was imposed by UL at the request of gas utilities and firefighters to minimize the number of unnecessary emergency calls from homeowners.An aviation website/newservice has requested their preferred detector company put out a low-concentration unit and AIM Safe-Air Products did. The AIM Model 935 Low-Level CO Monitor indicates "Lo" for CO concentrations below 5 PPM, "HI" for concentrations above 150 PPM, and the exact CO concentration in PPM for values from 5 to 150 PPM. When the Model 935 displays CO levels from 10 to 35 PPM, it also produces a slow warning beep and a slow red flash of its warning light, approximately once every 30 seconds. If the CO level rises above 35 PPM, the unit produces a fast warning beep and a fast red flash approximately once every 10 seconds. It sells for $75.For a lot more info: http://www.avweb.com/articles/codetect/While they do sell stuff (and ad space), I have found them to reputable and very pro-pilot in all their editorials.I won't even get into why HD sells a lot of crappy stuff.-David
*Interesting Bob. My doctor was telling me one day that he believes that many people develop headaches of varying intensity while barbequing over a gas/propane barbeque because the CO that it produces doesn't clear away fast enough for someone who is sensitive.
*Dave: Thanks for the web site. Will put in my order for one of those AIM products. Carbon monoxide may be a subject for Fine Homebuilding. Paging Andy Engel...
*Another source for the AIM 935 is Albert Donnay, MHSPresident, MCS Referral & Resources, [email protected], http://www.mcsrr.orgAlbert helped AIM develop the 935 and is one of the leading experts on CO poisoning, diagnosis and treatment.He has developed a protocol for CO poisoning available at http://www.mcsrr.org/resources/articles/P11.htmlIf anyone suspects they've had CO poisoning, be sure your Dr's are using this protocol; many in the medical community are woefully ignorant about CO, diagnosis, and treatment. Phill: I don't use a gas grill, but my charcoal grill pegs my Monoxor II at 2,000 ppm within 6" of the top of the grill, and, depending on wind, often produces well over 200ppm within 3' or so. Don't hang around the grill to close!Bob
*Bob...What does a wood fire produce?near the stream,aj
*AJ,Don't know; haven't seen a real wood fire in a while, except at some parties where it'd be a bit too geeky even for me to haul out the Monoxor II.Based on the physics of CO production, though, I bet it's be pretty high, especially as the logs burn down.Bob
*Well, his theory is specifically towards gas grills, not just because real charcoal burners are heading for extinction; but, if he's correct, he says the acrid smoke of the charcoal is a "natural" warning system that your body will generally heed; on the other hand, a gas grill is quite insidious and the symptoms are the first thing you notice.
*Sporty's pilot shop at http://www.learntoflyhere.com has a carbon monoxide dector for about $60. Look for the symptoms, from flight school...I think....were basically a cocky, can do no wrong, no fear attitude. Feeling invincable. Did I remember that right? Then ya land, have a killer headache, and throw up! Did I remember that right? Jeff
*After reading all this, is there a safe alternative to a torpedo? Has anyone used the infa-red I have seen in the Tool-crib catalog or is there a ceramic or other type that wuold work effectively on a site?
*Brad,I've never tested a torpedo so I don't know how likely they are to create significant CO.I wouldn't not use them just because of the _portential_ hazards.I _would_ have a good CO detector on site (like the new AIM discused in the thread) and pay attention to it. In may reported cases of CO poisoning, CO alarms had gone off, but been ignored/diabled.If possible, mount it high in the work space (CO's lighter than most components in air.Bob
*Brad: There are indirect heater that look like large torpedo heaters. They sit outside the envelope and a large duct is run inside. The combustion occurs on the other side of the heat exchanger from the building air.Bob: I agree wiht your first three paragraphs but have to disagree on the last (CO will stay high because it is lighter. CO (at 0.0740 pounds per cubic foot) is slightly lighter than air (0.0766), but that won't cause it to separate out. If it did, oxygen would fall to the floor (0.0846) and nitrogen would rise (0.0744). Outside of a science lab or the uranium hexafloride isotope separators at Oakridge, the only environment I've been in that is stagnent enough is a cave. CO2 (0.1170) settles to the floor in some caves but O2/N2 doesn't seperate much less CO/air. The CO will go with the exhaust gases - up do their temperature. And hopefully outside due proper ducting and ventilation. -David
*David,I used to wonder about that myself. I haven't seen a lot of houses with significant CO, but when I have they have had higher levels high in the room, even after beeing around long enough to cool down. I don't have the equipment to test CO2, but am told by Jim Davis (the dean of CO analysis who does a lot of testing of problem situations) that the CO2 drops to the floor. (He also teaches that CO rises, which, as I say, I questioned, at first.)I'm not absolutely sure about this, but that's my experience.Bob
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On a mail-list I sbscribe to, a neurologist has asked whether propane powered torpedo heaters could be the source of carbon monoxide for a patient of his whose a drywall hanger.
The answer is, of course, "they could be."
I'm wondering if anyone here has used CO monitors on the jobsite when using torpedos and what your experiences have been.
Bob