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    combustion analyzer (15 Posts)

  • Paul S Paul S @ 11:14 PM
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    combustion analyzer

    Hey everyone I just bought the Bacharach insight plus combustion analyzer...I just would like to know a few things....what exactly is O2?...I know its oxygen but how does it relate in the combustion process and what readings should I get....and how to change the O2 percentage....also what its the difference between CO & CO air free...and anything else you guys can add that can be of help greatly appreciated.....thanks Paul S
  • SpeyFitter SpeyFitter @ 12:47 AM
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    I hope I don't come accross as a jerk but I have to say this...

    Based on your questions you are NOT qualified to use this tool and if I were you I WOULD NOT even THINK of using it until you receive either a certification (Gas Fitting, Chimney sweep, what have you) OR, if you are certified, some gas appliance training (Timmie McElwain on this site provides gas appliance training if you wish to sign up) as well as perhaps some instruction on how to set up an appliance using an analyzer in person from someone that knows and is certified to do so, and perhaps some instruction from the analyzer manufacturer on how to use their tool on an appliance specifically. When you start getting into using an analyzer to set up an appliance if you do not have a clue what you are doing (and your thread leads me to believe this is the case - please do not take this the wrong way - I just want to make sure no one gets hurt) you CAN and PROBABLY WILL KILL SOMEONE.
    Class 'A' Gas Fitter - Certified Hydronic Systems Designer - Journeyman Plumber
  • Paul S Paul S @ 7:32 AM
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    its

    A simple question....if you are not going to answer it....then don't type at all...I'm not some homeowner trying to work on a gas/oil appliance.....its none of you're business what I know our don't know....this is a website to further your knowledge...any one else Paul s
  • SpeyFitter SpeyFitter @ 1:16 PM
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    I did answer your question

    You just didn't get the answer you wanted to hear since it requires further investment in proper training and/certification along with time & financial resources on your part to master.
    We WERE all there at one point, and I'm telling you, you NEED someone to show you, and train you in person, on top of doing some serious background reading so you can understand the consequences of what everything means along with what improper adjustment can do if you don't know what the numbers and readings are from your analyzer. The questions you asked tell me you don't have a clue. What homeowner on this site would want (err Pay) you to use an analyzer on their appliance if you are asking those types of questions?
    Class 'A' Gas Fitter - Certified Hydronic Systems Designer - Journeyman Plumber
  • Zman Zman @ 8:38 AM
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    Analyzer

    Paul,
    Here is a thread that may help.http://www.heatinghelp.com/forum-thread/144831/Combustion-analyzer-reading#p1289616

    Jim Davis and Tim McElwain are the 2 top combustion guys that post here. I picked up a couple of Tim's manuals, they are really useful.

    Manufactures will have their recommended specs in the product manual.

    Your question is the tip of a very large iceberg. There is quite a bit of other stuff you need to be looking at to get it right. Every manufacture is a little different and some of the old stuff out there is mind blowing.

    Carl
  • Paul S Paul S @ 7:23 PM
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    thank you

    Thanks ZMAN
  • Jim Davis Jim Davis @ 2:45 PM
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    combustion analyzer

    I have had techs in many classes that had combustion analyzers for years and didn't know what most of the readings really mean and which ones are bogus.
    O2 - Oxygen is air which starts at 20.9%.  The rest of the air that goes into the burner is Nitrogen at 79%.
    The amount of O2 that goes into the burner is controlled by draft and the amount of air that is used is determined by how much fuel is being burned.  If the O2 reading is above 9% the appliance is way underfired and totally inefficient,
    If the O2 gets too to low then there is too much fuel, assuming the flue and combustion air are good.  In this casse CO will be excessive along with the flue temperature.  Everything has to be in as specific range or it is not performing correctly.  Most manufacturers do not provide the complete list of combustion numbers that are needed on their equipment. 

    CO and CO "air free". 
    CO is the actual measurement that your analyzer is reading, which includes the O2 it is mixed with.  It is assumed all this air is outside the flame and dilutes the CO in the flame.
    CO "air free" is a theoretical calculation of CO directly in the flame with no additonal excess air or O2.  Although used by many it is not real.  It assumes perfect combustion exists in the flame.
    The CO2 reading is calculated and assumes the Btus of fuel never changes which is not true.
    The efficiency calculation is usually bogus and can be anywhere from 10% to 50% off.
    Knowing how to intepret analyzer readings takes training.  As long as the CO is low there is a chance no one will get injured from it, but not necessarily.
  • Paul S Paul S @ 3:39 PM
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    Jim or anyone else

    Thank you for that reply....very helpful. But, what about excess air?...and I should always go by the regular CO reading rather than the CO air free reading?and I'm going to purchase Tim's manuals on combustion testing (#'s 16-18)....and you're right about many technicians not knowing all the readings on there analyzer....this is my first digital one...I was taught with the old Bacharach test kit with the pump for the CO2...I used that when I worked for the oil company...and anything you can add would be very helpful...I've been working on allot of those power flame burners...duel fuel...and I use the analyzer allot residentially too...thanks Paul S
  • Tim McElwain Tim McElwain @ 7:53 PM
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    Paul there is an awful

    lot to this gas testing business. I know most oil men never tested oxygen (blue chemical in the wet kit) all they tested was CO2 (red chemical) and stack temp along with smoke.
    With the electronic analyzer you have much more available. I strongly recommend you get to one of my one week gas classes (Monday August 12 through Friday August 16) and then the three day Testing Design Gas Equipment class (October 7, 8 & 9). If you are going to do conversion burners then add that three day class (September 25, 26 & 27).

    Contrary to what is often promoted gas design and conversion equipment can be adjusted (fine tuned for maximum design firing rate).
    YOUR POSTING:
    Jim or anyone else
    Thank you for that reply....very helpful. But, what about excess air? WHEN O2 IS SET CORRECTLY IN RELATION TO DRAFT AND KEEPING CO UNDER 100 PPM AND STACK TEMP ABOVE 275°F O2 SHOULD BE ABOVE 4% AND CO2 AROUND 9.5% TO 10%.THIS WILL KEEP EXCESS AIR AT AROUND 20 TO 25%. ON DESIGN GAS ATMOSPHERIC EQUIPMENT YOUR EXCESS AIR WILL BE HIGHER AND YOUR O2 AND CO2 WILL BE DIFFERENT DEPENDING ON HOW MUCH EXCESS AIR.YOU HAVE, and I should always go by the regular CO reading rather than the CO air free reading? AIR FREE IS WHAT YOU WANT TO USE IT IS TYPICALLY THE HIGHER OF THE TWO CO READINGS  and I'm going to purchase Tim's manuals on combustion testing (#'s 16-18) COME TO SCHOOL AND THOSE MANUALS ARE INCLUDED PLUS YOU GET INSTRUCTION, THE MANUALS ARE NOT MUCH GOOD WITHOUT THE TEACHING THAT GOES WITH THEM.....and you're right about many technicians not knowing all the readings on there analyzer....this is my first digital one...I was taught with the old Bacharach test kit with the pump for the CO2...I used that when I worked for the oil company...and anything you can add would be very helpful...I've been working on allot of those power flame burners...duel fuel...and I use the analyzer allot residentially too...thanks Paul S
    DRAT SHOULD BE -.02, -.03 IS NORMAL AND DETERMINES IF IN FACT YOU HAVE SUFFICIENT AIR FOR COMBUSTION.

    WE CAN ANSWER YOUR QUESTIONS HERE BUT THIS FORUM CAN NOT BE USED TO TEACH THE COURSE YOU NEED IN ORDER TO DO THE JOB RIGHT.

    IF YOU CAN'T GET TO MY CLASS ON COMBUSTION TRY TO GET TO JIM DAVIS CLASSES.
    This post was edited by an admin on July 7, 2013 8:06 PM.
  • Paul S Paul S @ 8:09 PM
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    tim

    Is this only in Rhode island...or do you come to NYC ever....and do you think your manuals #16-18...would be helpful in the time being...thanks Paul S
  • Tim McElwain Tim McElwain @ 2:28 PM
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    I was recently in

    New Jersey. I would come to NY but there has been no real interest shown when I tested the waters about coming.

    The three day courses really have to be done in RI as we have live firing of equipment and that is impossible to haul to NY.

    I get a lot of folks who come from NY to my training center so that is what I really try to get folks to do. At the center you get a much more complete presentation.
  • Jim Davis Jim Davis @ 2:46 PM
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    combustion analyzer

    Paul, Excess Air is a calculation off of the O2 reading.  If your O2 is 3% your excess air is 15%.  If your O2 is 5% your excess air is 30%.  It is just another way of saying O2.
    Most regulations for CO and how much equipment can make are based on "Air Free" CO calculations.  400ppm "Air Free" CO is the standard for commercial and industrial flues.  It is also the same level for all ventied residential heating appliances.  Using "Air Free" to tune equipment can leave it lean unless you shoot for higher numbers.  Some say set burners for 100ppm "as read" others say 100ppm "Air Free"  Actually you shouldn't set burners for either one.  They should be set for the lowest O2 and the best flue temperature(not the lowest.) CO is monitored and is the brakes as far as fuel air mixture.  If the CO gets above 100ppm "as read' or 120ppm "Air Free" you should stop.
    On a 3-pass boiler making 180 degree hot water should have a flue temperature no lower than 350 degrees or it is underfired and inefficient.  A 4-pass boiler would run closer to 300 degrees.
    I sold Power Flame burner for years and they set up fairly nice if they are firing towards the top of their capacity.  3% O2 in high fire pretty common.  Low fire needs a little more air 5% to 6%.  Flue temperatures are based on the type of equipment, what it is making, and the firing rate. It is not fixed but should be in a range,
    With the glut of natural gas these days I would think gas companies would penalize you for having dual fuel.  In the 70,s, 80,s, and 90,s you got special pricing if there were fuel curtailments.  Didn't know they still did that.
    There sometimes is a trick for setting up dual fuel burners to make them automatic change over.  I'm guessing some of these new direct coupled electronic controllers can make those adjustments today?
    Planning on being in northern NJ in September, maybe?  Will know better next month.
  • Paul S Paul S @ 7:33 PM
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    jim

    How do I enroll in your classes? Thanks Paul S
  • SpeyFitter SpeyFitter @ 2:33 AM
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    Wow Paul

    Do I get a Thank you now that you are actually following my advice?
    Class 'A' Gas Fitter - Certified Hydronic Systems Designer - Journeyman Plumber
  • Jim Davis Jim Davis @ 7:49 AM
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    combustion analyzer

    Pual,
    Go www.nationalcomfortinstitute.com for the schedule.  Also you can call me anytime and I can fill you in on the class or any other questions.

    800-633-7058
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