Mark Hunt, et al; -DF

Dan Foley

Curious what you think of this article?

-DF



http://www.supplyhousetimes.com/CDA/ArticleInformation/features/BNP__Features__Item/0,5333,143391,00.html




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ScottMP

WOW

Seems to go against everything I've been told by Timmie, Mark and Jim Davis.

Would love to have this gentleman come to the wall for a discussion.

I'll wait for Hunt and others to respond. Remember everyone, a blue flame is O.K. !!!

Scott

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Larry (from OSHA)

Wow

I'm going to turn down the volume on my computer before Mark Hunt gets going with this one!!!

There seems to be quite a bit of work (education) to do with this.

Larry (from OSHA)

jp_2

don't go overboard!

some of his points are correct.

though, as far as CO2 symptoms I can't find sleepiness as one of them.

# Nausea, vomiting, dizziness, headache, rapid breathing, flushing can occur with carbon dioxide poisoning.

# Severe cases progress to confusion, convulsions, and loss of consciousness.
accoording to emedicine.com

he is right about natural gas having only one carbon.

article seems a bit too generalistic.

so, if you attack, attack paragraph by paragraph, be specific and not generalistic!

Dave Bush

I take issue with the following:

What such furnaces do produce (like gas ranges and ovens) is a lot of carbon dioxide and water vapor. You have likely noted all the moisture on your windows from the cooking process on Thanksgiving Day. Much of this comes from the gas combustion process. And this is why more people aren’t killed by all the thousands of furnaces that continue to operate throughout North America with unknown holes in their heat exchangers.

The house I grew up in, and my grandparents homes were outfitted with no gas cooking appliances whatsoever. This effect is the result of adding latent heat (from the steaming hot food on the stove) to the cold window surface. The window surface temp is raised above the dewpoint, and fog happens. It's got nothing whatsoever to do with gas cooktops and ovens.

If it does, why doesn't this phenomena occur during the preparation of Summer dinners?

If it does, why does this phenomena occur in all electric homes?

I get concerned when I see such misinformation in trade journals, especially ones that go to non-technical people, who might try to offer advice to technical people. Pretty irresponsible, really, to equate fogged windows to CO productions.

Here's another:
Now, don’t get me wrong. I’m not trying to encourage anyone to forego repairs to defective furnace vents or heat exchangers, because furnaces do produce significant amounts of carbon dioxide, which tends to make people drowsy (do you ever get sleepy on Thanksgiving?).

Drowsiness after T=hanksgiving dinner has been linked directly to high levels of L-Tryptophan, a naturally occuring amino acid, in the turkey. You're not supposed to give your dog a lot of Turkey, because of this. It will poison a dog.

Recognize this: Virtually no carbon monoxide or any soot comes from a blue flame. But when a flame is yellow or has yellow tips (other than from dust particles), soot, carbon monoxide, and aldehydes are likely being produced.

Anybody here ever work on a Cozy or similar counterflow wall furnace??? The flame is, according to the MFG, supposed be at least 1.5" blue, and the remaining 3.5" or so is supposed to be yellow. No kidding. Jsut replaced one. Zero CO in the flue. 3.5" of yellow flame.

Colors are colors. Meters are meters. I don't use a chromatograph the determine of voltage is present.

His facts are skewed, and I think that maybe the article was a spur of the moment thing, but it could provide a false sense of security, or tell someone what they "want" to hear. Bad news.

Sorry for the length. I flipped a bit when he went after Thanksgiving dinner.:=}}}

jp_2

I agree!

Dave Yates (PAH)

At long last!

The reason why I'm always confused(G). Starting tomorrow, we'll be winning more bids than ever before - our furnaces will now be 100% efficient - even the 80+ models. I'm thinking of selling squeegees too.

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Dave Bush

Saves on the

flue piping.........:0

Mad Dog

The malaise and general piss-poor attitude

toward CO and how the general public- including this industry deal with it are painfully evident. Several times a week in the New York Papers, I read about Co deaths. I've tried Full page ads in Local papers, FREE!!! testing of homes, free clinics with the local fire depts. No one wants to talk about it until kids are dead. I still!!!!!!!! get the raised-eyebrow look when I urge homeowner to go out and get atleast !!!!! The basic home center detectors...."yeah I know, but my husband says we don't really need 'em." A lot of CO Morons out there still!!!!!! Mad Dog

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chuck shaw

matt

i hear and see it every day. Personally I cannot imagine installing a gas appliance without testing, or an oil burner. People just dont know or understand. Or maybe they just dont want to know. The biggest coment I get is "that tool costs $$$$" and my answer is after a death, how much will your liability insurance go up.

Bottom line is, if you dont test you dont know. Someone may be hurt.

By the way Matt. You still owe me a phone call!!!

Chuck

Unknown

I sent an e-mail to

Jim Wheeler concerning his article. I do not want to get into debating individual comments he made. What I told him was the story theme which is to downplay the importance of being alert for possible high levels of CO on all equipment not just gas furnaces. It is very interesting I have sent several articles on Carbon Monoxide to BNP publications and had them rejected. I wrote one back several years ago for the NEWS and it was rejected as too strong. They did finally print a watered down version. There is a lot of noise made about this but when it comes to facing the absolute truth the fact is it is ignored.

Recent articles in PM Engineer and Plumbing and Mechanical on other subjects have numerous errors and incorrect information. I have gotten tired of writing letters to these publications to correct mis-information. It seems they need someone to proof read these for technical correctness and content.

What say everyone DO GAS FURNACES CREATE A SIGNIFICANT CARBON MONOXIDE THREAT? That is the title of the article and it asks a very important question. He then says Most problems can be prevented by following basic gas codes. What codes have anything to do with Carbon Monoxide???

I am trying very hard to not take the article apart piece by piece. It is full of half truths which is what causes people to relax and think everthing is okay becasue it got printed in a very well known trade publication. It is a truth that there is a certain group who write for these magazines and it is only that group who gets print. I am sure they get paid. Well here is an offer I have made them, I will write the truth on many trade related subjects and do it for FREE. A half truth is a lie no more no less.

Oh Just one and then I will be quiet - FLAME COLOR HAS NOTHING TO DO WITH WHETHER IT IS MAKING CO OR NOT.

Mark Hunt

D'avec leurs t

Mark Hunt

I did it Timmie


Part by part. Well.......as much as I could stand.

This guy made some deadly remarks and I will not let it go. They will all be hearing from me very soon. Not with emotional outbursts, just the facts. I will challenge Mr. Wheeler to produce the facts that he based his article on.

You and I both know where those "facts" came from.

Too bad for him that I got nothing better to do than read this stuff. Too bad for him that I study this.

The old saying goes, "Don't bring a knife to a gunfight".

Mark H

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Jason_15

Great post Mark !!! Hope you eat that guy up. he has it coming........I always enjoy your posts. And you are deadly accurate with this one.

Mark Hunt

Jason


Thanks for your kind words. I appreciate them.

This has become my passion and I take it seriously. I didn't think this stuff up on my own, I was shown what the truth is.

I'm just passing it on.

All of the diplomatic crapolla out of the way, yah, I'm looking forward to having this guy for lunch.

I'll keep you posted.

Mark H

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Glenn Harrison_2

UNBELIEVABLE

I will say this, as a tech who has been poisoned by Carbon Monoxide, from a boiler that had a pretty blue flame, but was producing over 2000 ppm of Carbon Monoxide, was not tampered with, and was not drafting due to the combustion air being used up by the fireplace running, I can say this guy's article makes me cringe. How could so many wrongs be packed into one article? It's thinking like this that will put homeowners and technicians at stake of sickness and death from CO poisoning.

I had two 80% furnaces last week that were producing 100 and 200+ parts CO due to the heat exchangers failing, and the pressure switches were far from tripping. Of course this CO was going up the chimney so they don't count (YEA Right)!

Then there was the 90% furnace I worked on last Friday that the HX had failed and the far left burner had almost total roll out from the cell, and quickly raised the CO levels near the furnace room to 15 ppm and off the scale CO levels in the flue before I shut it off.

25 years of teaching and writing in the HVAC field! Me thinks it's time for retirement before he hurts someone!!!

At least he got one thing right, OIL produces carbon monoxide.

Go get him Mark, make sure you give him a link to this thread so he can get the big picture of his poor and dangerous article.

John R. Hall

Timmie

The News cares. Read my article next week which I drew a big assist from Jim Davis on. It is an indictment of our own trade.

Mark Hunt

Glenn


Always good to see your posts.

You're one of the few that get it. (Jason gets it too)

All the best!!

Mark H

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Mark Hunt

0 Co in the flue


That is a dangerous situation. There should NEVER be 0 CO in a flue.

E-mail me and we'll discuss it.

Mark H

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Unknown

John you know that was not the case

a few years ago. I feel it is only because you have been relentles in your pursuit of this subject that the NEWS has come on board as a concerned party as related to CO.

jp_2

to mark hunt

what I would like to know is how the author did his research and where he got all this data from????

minor point, inert gases are only in the right most column of the periodic table, CO2 in not inert.

CO2 is a problem for divers, bottling plant workers......CO2 kills too, just not from cooking dinner.

do a search "carbon dioxide poisoning" its out there

Kal Row

another proof of how valuable the WALL is!!!.

this man has 25yrs of experience but not the 25 years of learning,

on the “wall” everything gets “truth’ed” out – no bull is left on the table

also: another nail in the coffin of the saying “practice make perfect”, – dead wrong, cause the truth is, “practice makes permanent”, if you practice wrong, you will have a hard time unlearning it, so, we have to continue our “edge-u-me-cay-shun” every day, or we die, or worse, we kill people!!!

Jim Davis_3

Originality

Got to give the guy credit for originality. Just when you think every that could be said wrong about CO has been said, someone comes up with a new one. I particularly like the fact natural gas has very little carbon in it. Didn't realize this was Hydrogen fuel. Notice he said he was called on a job because the furnace stopped before it killed anyone. Bet he made sure it wouldn't stop next time!! By the way what do you put a closet in to enclose it?? I remember in 2002 when a boiler manufacturer had an article in a trade magazine that said sniffing the vent cap for an odor was the best way to check for proper fuel-air mixture. In 1999 in a different trade journal we read, CO is easily detected with Gas Leak Detectors, is always has an odor and always make soot and you should eye ball the flame for at least 5 minutes to determine if the flue is restricted.
This guy was fired from his last technical writer job for bad information but I guess he didn't get the hint.

jp_2

jim,jim,jim

""" I particularly like the fact natural gas has very little carbon in it."""""

jim, he got this one right from a chemistry point of view.

CH4 ---methane, natural gas

C3H8 propane

C10H22 kerosene , best I could find.

C15H38 best I could find for heating oil.

so sure he's right, it has the least amount of carbons per molecule. but his chemistry seem to be lacking so I'm not sure what point he was tring to make with this fact.

Kal Row

last week someone posted a bad CO reading on a new boiler..

because of something in the burner area that got lose in shipping!!!!

so much for new boilers...
test!test!test!

Jim Davis_3

When talking about natural gas as a combustible fuel, it should relate to the ultimate CO2 of the fuel to be combustible which in turn determines the BTU value of the fuel. Natural gas has an ultimate CO2 content of 11-12%, Propane 14-15% and Oil 16-17%. Not being scientific it appears that it would take 11-12 molecules of CH4 for natural gas to be combustible. Propane would be about 5 molecules and oil only 1 molecule. Saying that natural gas doesn't have much carbon in it would be the same as saying it doesn't need much oxygen to burn it because air is 79% Nitrogen.

jp_2

off topic

jim we are getting a little off topic i think, not sure we are talking about the same thing here? would you be interested in further discussion of this on its own thread? off hand I do not see how you can discount h2o formation energies?

each mole of methane CH4 produces mole of CO2 and 2 moles H2o, therefore 33% production is CO2? why 11%? don't understand your numbers? off hand it seems that h2o energies are higher than co2 energies.

if I calculate energy produce by propane I get very close to the numbers I find on the web 93.000btu's/gal, thats using h2o production?

edit:

""""it should relate to the ultimate CO2 of the fuel to be combustible which in turn determines the BTU value of the fuel. Natural gas has an ultimate CO2 content of 11-12%,""""

jim I keep reading this over and over, this is real confusing?

I see CH4 + 2(02) = CO2 + 2(H20)

if CO2 is 11-12% what is the other 88-89% ?


jim

Unknown

Natural Gas

A little information about Natural Gas. It may contain much more carbon than you think. This is an extract from one of my books "Fundamentals of Gas Volume I"

PHYSICAL CHARACTERISTICS OF FUEL GASES

Natural Gas

Petroleum gases are hydrocarbons - a chemical structure of hydrogen and carbon. Natural gas is primarily methane (CH4) and ethane (C2H6) but it will typically contain a number of heavier hydrocarbons when it leaves the well. Among these are propane and butane (the prime constituents of LP-gas) pentane, hexane, septane, octane and decane (the natural gasoline's). Natural gas right from the well will also contain impurities such as water, carbon dioxide and helium. The volume of heavier hydrocarbons is called the "wet gas" content. These heavier hydrocarbons are normally removed from natural gas by condensation and are used in the manufacture of LP-gas and gasoline. Impurities are also removed during refinery processes and the resulting "dry" gas is the natural gas commonly marketed.

At temperatures above (minus) - 260 degrees F at atmospheric pressure natural gas occurs as a gas. It is normally transported from the source to the consumer in a gaseous state by pipeline. Recently methods have been developed to transport natural gas as a relatively low pressure, low temperature liquid by ocean-going tanker. To accommodate periods of peak demand, natural gas maybe stored as a pressurized gas or as a pressurized low temperature liquid. Natural gas is costly to liquefy because very low temperatures are required. The use of liquefied natural gas as a motor vehicle fuel is possible only with thick-walled storage tanks, well insulated to maintain the fuel in a liquid state. As a practical matter, natural gas is only liquefied to make bulk storage and transportation possible. It is also possible that some foreign LNG may have a differnt BTU content than typical gas from within the US.

Natural gas is lighter than air, weighing from 56% to 79% of the weight of an equal volume of air. The specific gravity of natural gas' is, therefore, within the range of .56 to .79. Natural gas released into the atmosphere will normally rise and mix readily with air.

When burned efficiently, one cubic foot of processed or “dry" natural gas will normally produce 900 to 1,200 British Thermal Units (Btuts) of heat depending on the exact specific gravity. This value is called the gross heating value of natural gas and is an important factor in the design and operation of heat producing appliances.

Natural gas is colorless, odorless, and nontoxic. Although nontoxic, it can displace oxygen in the air and cause unconsciousness and death through asphyxiation (death due to lack of oxygen). To aid in the detection of leaks, odorants are normally added to natural gas before distribution. Mercaptans are sulfur compounds commonly used as odorants. Although added in small amounts, they provide an effective means of detecting gas leaks.




Natural Gas Analvsis

Carbon Dioxide CO2 1.10%

Nitrogen N2 - .78%

Methane CH4 92.59%

Ethane C2H6 4.17%

Propane C3H8 .97%

Butane, Pentane, Hexane ~ 100.00%

As can be seen from the typical make up of natural gas it has more than one part Carbon. CH4 is Methane just one of the parts of natural gas. The amount of methane in gas may vary in differnt parts of the country.

I have some detailed discussion on this topic over at Oiltechtalk "ask Tim McElwain a question".

Unknown

Just a little more education if

you will allow me.

A Bunsen-type burner flame (with a reasonable amount of primary air) has several color zones. Each of these zones marks a stage in burning of the gas. On the burner tip is a thin, blue cone called the inner or primary cone. Inside the inner cone is a darker area, the unburned, fairly cool gas -air mixture. The inner cone marks the first step in the burning process. There gas is burned to form products such as aldehydes, alcohols, carbon monoxide and hydrogen. If proper burning does not take place these are released into the final products of what would be incomplete combustion.

A darker, outer cone surrounds the inner cone of a Bunsen-type flame. Air around the flame diffuses into the flame to take part in the burning at the outer cone. If enough air is present and other conditions are favorable, products from the inner cone are completely burned here. This burning yields the final products, carbon dioxide and water vapor (products of complete combustion).

An outer mantle surrounds the cone of a Bunsen-type flame. Since burning usually is completed at the outer cone, there are almost no unburned gases at the outer mantle. This nearly invisible mantle glows only because of the high temperature of the final products of combustion.

Temperature of a gas flame can vary, depending on a number of factors. Two major factors are the type of fuel gas and the amount of air premixed with the gas. Flame temperatures are not the same at all points in the flame. Temperature in the unburned air- gas mixture inside the inner cone is fairly low. Highest flame temperatures usually occur at a point just above the outer flame cone.

A cold body placed in a flame reduces flame temperature in the area of contact. Too great a drop in flame temperature can quench the flame. If this condition occurs, products such as carbon monoxide can escape from the flame before they are completely burned. Usually the outer mantle of a blue flame can impinge on cool surfaces without causing incomplete combustion of the gas. But inner and outer cones, especially the inner cone, should not impinge on surfaces colder than about 1200 F.

Just a note about yellow flame burners, there have been yellow flame burners for a number of years. They are not a problem as long as the flame does not impinge on cooler surfaces. FLAME COLOR HAS NOTHING TO DO WITH MAKING CO.

With a primary aerated burner we adjust the flame to get a soft blue flame but do not be fooled with thinking that a blue flame means no CO.

WE must test and also we need to be educated.

Darin Cook_3

Tim, on a side note

When the natural gas supplies cannot keep up, what do they augment the nat gas with? Propane? Butane? Do you have any idea how much that effects the btu content? What about the combustion of the mix of those fuels? Would it be possible for the CO numbers to spiral up with that mix of fuels? Obviously we can set up a burner with the proper pressure with a manometer and the combustion numbers with a combustion analyser, but what happens when that fuel mixture changes? This must happen quite a bit when the real cold weather hits but I have not seen anyone bring the issue up. Or is it even worth losing any sleep over? Thanks once again for your knowledge and experiance.







Darin

Unknown

Mixing Propane or other

gases definetely changes the ultimate products of combustion. Remember the burners are set up for a gas with a specific gravity of say .6 and propane SG is 1.52 also a different BTU content. Pressure should not however vary due to mixing. When I was with the gas company and they mixed propane it was going to be a long night for the service department. Pilot outage, delayed ignitions, odor complaints and the list goes on. It is somewhat more fortunate today that most gas companies are using LNG when peak demands for gas due to cold weather occurs. The thing that really becomes a problem is adjusting with the mix and then not going back after they stop mixing. This usually results in a sooted up piece of equipment. I have seen heating, water heating and cooking equipment and do not forget the dryer all carboned up. CARBON MONOXIDE GOES THROUGH THE ROOF WHEN ADJUSTMENTS FOR PROPANE ARE MADE AND NO ONE GOES BACK TO SET BACK TO NATURAL GAS MIX. BETTER TO JUST LEAVE THE EQUIPMENT ALONE AND NOT ADJUST.

When pressure problems occur in the inner city area on the old cast iron systems it presents even more problems.

This is why we someday need devices that shut equipment off when CO is present.

We cover all this in our Fundamentals of Gas seminar and explain how gas companies purchase gas and why they have to mix.

Mark Eatherton1

Guilty as charged...

Clear back in 2000, I wrote an article for P&M Magazine. This was prior to having attended Jim Davis' eye opening classes. Heres what I had to say in that article...

Posted on: 06/01/2000

Is There A Killer In Your Basement?
by Mark Eatherton


Having been in the mechanical service business for more than 22 years, I’ve had my share of carboned up boilers to contend with. In most every case, the occupants of the dwelling were unaware of the potential dangers that existed, and didn’t even know that a problem had occurred.

Of all the sooted up boilers I’ve seen, a reasonable and logical cause explained each and every case. One way or another, the incomplete combustion of flammable gas is what is responsible for the production of CO.

The intent of this article is to make all service technicians who work on or around boilers and other gas-fired appliances aware of the following:

What conditions cause carboning and carbon monoxide production.
How to eliminate those conditions.
How to quickly identify an existing problem.
What measures should be taken to avoid further carbon production.
Although I’ve seen many ways for carbon and, consequently, carbon monoxide to be produced, I’m positive I have not seen them all. Experience will show that just when you think you know everything there is to know about a given subject, Mother Nature comes along and shows you something you hadn’t counted on. But here are some real experiences I’ve had:



The Rain Forest Syndrome
I’ve had numerous carbon monoxide cases involving low mass copper finned tube boilers used for everything from pool heating to hot tub heating and even house and domestic hot water heating. What typically happens in these cases is the boiler’s heat exchanger is exposed to operating conditions well below the minimum allowable operating temperature of the boiler system.

Typically on domestic hot water heating systems, the cold water was introduced into the boiler at its inlet. During peak loading, the flue gasses are cooled down well below their condensation point. When these flue gasses condense and drop off the heat exchanger, they drip onto the burners below. This dripping, or what I typically refer to as a “rain forest in yer fire box,” causes the flame to spatter, and burn dirty. This dirty burning causes wet carbon deposits on the copper finned heat exchanger.

Eventually, the heat exchanger flue passages become completely plugged, and major “roll out” from the burner tray begins. In most cases, the roll out is serious enough to cause the control wiring to short out to ground, and the primary boiler transformer fails. In most cases, that is.

In the case of newer boilers equipped with roll out protection gear, sometimes the roll out occurs in such a manner that the protection switch does not “see” the roll out. Consequently, someone gets sick, or worse, dies. Until a roll out safety switch that monitors the entire width of the combustion chamber opening aperture is invented, this will continue to be a problem. (Hello, GAMA, are you listening?)



The Case Of The Overbearing Kitchen Exhaust Fan
I once had the unfortunate experience of being partially poisoned by two large boilers in a hotel mechanical room.

I was in the mechanical room installing an energy management system. Meanwhile, I wasn’t really paying a whole lot of attention to the combustion process occurring alongside me. Fortunately, a hotel engineering employee was aware of the problem and checked in on me — only to find me passed out on the floor.

Further investigation proved the following: In a large production kitchen located 50 feet from the boiler room was a powered hood exhaust system. This hood also had a makeup air system that was untempered. When it was cold outside, the makeup system dumped cold air directly onto the necks of the chefs on the cooking line. The head chef convinced someone from engineering to shut it off.

However, removing 10,000 cubic feet per minute caused substantial negative pressure to be exerted on the building as a whole. The negative pressure was measured at a negative 3.5 inches of water column. The boilers in the mechanical room were a natural draft type of boiler whose breaching pressure is generally negative 0.02 inches of water column. Guess where the flue gasses were going? Not outside like they were supposed to, that’s for sure.

And before you ask, yes, there was outside air available for combustion. However, it had been partially closed off due to cold air flowing into the mechanical room and freezing the pipes. As a result, the makeup air system had to have a makeup heater installed on its intake in order to deliver tempered air to the exhaust hood. In addition, the system was interlocked into the exhaust fan to insure that one could not run without the other. Finally, the mechanical room’s air had to be “isolated” from the building’s air. This entailed installing tighter doors, seals and caulking to shut the annular space between the ceiling and the walls. If it had been isolated to begin with, none of this probably would have happened.



These Things Need Air?
I once had a commercial 80-gallon water heater located in a closet. This closet got its combustion air from two 6-inch vents coming through the ceiling. At some point in time, someone decided the cold air that came through the vents was too much. As a result, they installed sheet metal caps on the combustion air vents to stop the incoming air. Evidently a pipe had frozen in the closet at one time.

We were originally called in to figure out why the pilot kept going out. Using my finest tunnel vision glasses, I replaced the thermocouple and thermocouple magnet. The next day, I got the call — no pilot again. This time, I took my tunnel vision glasses off, opened my mind and my eyes, re-lit the pilot, stayed inside the closet with the door closed, turned off my flash light and observed the following:

“Boy it’s dark in here! Sniff, sniff. Hmmm, that smells like partially burned natural gas.”

Much to my surprise, I found that when the water heater had completely exhausted the small closet space of all its air for combustion, it began pulling combustion air down the flue pipe. Guess what? You can’t sustain a flame in the presence of carbon dioxide. The main burner and the pilot eventually was snuffed out due to a lack of oxygen.

I’ve seen other cases where similar conditions existed, and someone installed an electronic ignition system. When the pilot gets snuffed and an electronic ignition system is on line, the system keeps going back for a re-trial for ignition. Short cycling. The pilot and main burner flame catches, snuffs out and re-tries again. Now between cycles, enough oxygen seeped back into the room to allow combustion to start, but not enough to sustain continuous combustion. Consequently, carbon and carbon monoxide are produced, plugging the flue gas passageways and causing major flame roll out. This continuous, undetected roll out is what kills people. To solve this problem, thermal siphon traps were installed on the combustion/ventilation air.



Deadly Dust
Quite often, during the course of home construction during the winter, the newly installed heating system is called upon to provide temporary construction heat. Everything goes along OK during the final days of the framing stages. The problem pops up during insulation and sheet rock finishing.

You see, when an appliance combusts gas, it consumes a substantial amount of air. If there are particles of dust floating in the air, these particles mix with the gas being combusted and retard the combustion process. The carbon accumulates as a dry carbon on the heat exchanger surfaces, eventually blocking the flow of gasses up through the boiler.

If and when dust will be in suspension — i.e., insulating, sheet rock sanding, acoustical applications etc. — gas-fired appliances must be shut off. Either that or a guaranteed clean source of combustion air be made available to the appliances. Typically isolating the boiler room and providing it with the required amount of combustion air insures a clean burn. Notify your builders in writing so that if and when it does occur — and I guarantee you it’ll happen —your liability is limited.

Speaking of limiting liability and exposure, did you know that carbon dust is still a dangerously explosive material? When the dust gathers in suspension in the open air under certain concentrations, you have a bomb the size of that room. All it needs is a source of ignition and boom, it’s all over. Make sure that your employees are using a HEPA vacuum or require that the vacuum be kept outside the building. Also, make sure your employees are using NIOSH-approved ventilators.



The Drive By Test
This is probably the easiest way to spot a killer, but requires a lot of tact on your part in delivering the message. As you’re driving down residential streets in a known natural gas area, look for blackened flue pipe terminals. If you see a vent terminus, and you are reasonably sure it is not connected to a fireplace, and the vent cap is blackened by soot, you got yourself a problem. The next step is the hardest part of saving some lives. Do you:

A. leave a note on the person’s door telling them that you know they have a killer in their basement.

B.tell them in person that you know they have a killer in their basement and you want to show them where it is and how it can be eliminated.

C. shut off their gas meter and leave your business card in their door telling them to call you immediately.

D. tell their neighbors to tell them that they have a killer in their basement.

There are many correct answers. If it’s a relative of yours, C would be appropriate. If it’s a neighbor you don’t like, maybe D or A. If you can convince the homeowner that you’re not kidding them, B is the most appropriate. If B isn’t possible, consider A buffered with D. The neighbors can probably convince them, if you can convince the neighbor. If they don’t trust you, tell them to call their local gas utility, and the utility will yank their gas meter.

I’ve experienced this drive by stuff before, and it’s not easy. You are somewhat out of place doing a cold call on the homeowner. Be professional, apologetic, courteous and downright serious. We’re talking about a life and death matter here. You shouldn’t have trouble convincing them that you know what you’re talking about. You are after all, “The Expert.”

END OF ARTICLE

I dont remeber where I wrote it, but I remember writing an article somewhere telling people to do the "black finger" test. If you stick your finger into the flue, rubbing the sides of the flue and pull it out, and theres carbon on it you DO have a problem. If your finger comes out clean, it's OK...

Boy was I ignorant then!! My sincerest appologies to those people that I may have misled.

Now, almost 5 years later, I probably would have said one additional thing that I didn't say, nor was I doing then,

If you don't test you don't know, and if you don't know you could kill someone. Including yourself!

TEST TEST TEST TEST TEST

ME

jp_2

I think I see

ok, I think I see what you are talking about, you are measuring "diluted" co2 in a vent? but if your co2 levels are always around 11-12% how are you determining btu content.

how do you determine the amount of air dilution in one device from another? I don't see where this can be that accurate.

"""" Not being scientific it appears that it would take 11-12 molecules of CH4 for natural gas to be combustible""""

could you explain this a little farther?

Unknown

jp go over to

www.oiltechtalk.com and go to section "Ask Tim McElwain Questions" I have been teaching on Fundamentals of Combustion for several weeks and it is all archived there. I think what is posted there may answer your questions. If not it may raise more questions. I would then suggest you attend my classes on Fundamentals and then combustion testing. If not convenient to come to RI then Jim Davis has classes all over the country, look into his classes.

jp_2

Ok, as i thought

nice site tim, lots to read. thanks for the directions.

one question though, what division of a percentage can you measure CO2? 1%, 1/2%, 1/4%? just curious.

thanks but RI is a long way to go to ask a couple of question. I'm just asking some questions not looking for training.

Unknown

Jp not quite sure

what you are looking for. If it is what percent of the total products of combustion is CO2 I would have to look that one up as I do not have it off the top of my head. If it is what part of the stoichometric total based on an ultimate CO2 at 11.7% then it can range from 8.5% to 9.5% for natural gas and 9.5% to 10.5% on LP.

The concern over CO2 in Jim Wheelers article is not unfounded. The excess amounts of CO2 that may be recirculated back into the combustion zone can cause a cooling and quenching of the flame which results in Carbon Monoxide. CO2 is not really the concern for safety however as the main concern is CO which can be caused by many things not the least of which is CO2 contamination of the combustion air supply. Example is one of the number one causes of CO poisioning is automobile exhaust. Measuring CO2 on that would be useless.

I am curious do you conduct combustion tests on your equipment. I am not sure what your profession is so I am asking as a technician do you test?

Unknown

Mark Hunt have you

received a reply from your e-mail to Jim Wheeler? I have not and I specifically ask him to contact me. I gave him all my numbers.

Jim Davis_3

Supply House Times

Tim,
I have received an E-Mail from both the Editor and Publisher askings me to respond by letter to everything I take issue with, but not to discredit the author. I will be sending it out this week. I may E-Mail you a copy before I send it for your comments.

Mark Eatherton1

How...

does one respond to something of this magnitude WITHOUT discrediting the author??

I guess you just "take issue".

Should be interesting.

ME

Unknown

Jim Sounds great

I look forward to looking it over. I aree with Mark E it is difficult to not take issue with the author but I guess if counter facts are presented and the truth set forth it then is relative to subject matter and not personal. It may just be this gentlemen who wrote the article will learn something.

I am glad they are responding it shows that they are interested in getting to the truth.

Go get them Jim!!! Just be nice!!!