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Carbon Monoxide

hombre de oleo
hombre de oleo Member Posts: 17
in THE MAIN WALL
Fellow Wetheads. I have looked everywhere to no avail. Help me answer this question. What are acceptable CO levels emitted from gas boilers operating properly? Range of levels? How about a boiler operating poorly? Thanks in advance. Greg

Comments

  • Unknown
    Unknown
    ANSI Standard allows

    400 PPM. That is the allowable level in the flue gas sample. However anything over 100 PPM should have some service done to lower the level. I shoot for as low as I can get it with safe CO2 8.5% to 9.5% with O2 above 4% typically 5% to 6% is normal. This will allow adequate excees air levels for proper operation. As you are able to control air with input being as close to design your efficiency will be increased with lower levels of CO. On conventional equipment flue gas temp should be 350 to 550 degrees F that is Net Stack temp. Nothing above 600 degrees on gas is allowed.

    When you get into Mid eff and Hi eff those readings may change and you will have lower flue gas temps.

    For some real good info go to the Roundtable for info on CO, I will bring back up a very large discussion that was on going a while back.
  • rudy_2
    rudy_2 Member Posts: 135
    Just to clarify

    That 400 ppm limit is as measured on an 'air free' basis which is a calculation based on the CO and O2 or CO2 reading.

    As far as I'm concerned 400ppm (air free) is an unacceptably high level. When I run service (oil or gas), I'm comfortable with anything under 50 ppm air free. Between 50 and 100 I start gettng concerned and above 100ppm air free, I double check everything (ie fuel pressure, draft, burner alignment, etc).

    CO air free readings on light off are a little different. It's not unusual to see a bump up to 100 ppms, when I start seeing 200+ on light off, I consider that to be pretty rough and start double checking burner spec's.
  • hombre de oleo
    hombre de oleo Member Posts: 17
    CO revisited

    I agree with you Rudy. I deal almost exclusively with oil, and when I do an efficiency test w/my Testo I usually see 0-9 PPM.My question was a baseline more or less to see what natural gas or propane aficianados see in their day to days.I went to my plumber friends, the local counter help and their bosses to no avail. Thank you much. Greg
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