combustion tester

tom_49

Actually I didnt realize you were Jim also, I was responding to Jim Davis.

Anyway DAM is a term Jim Davis uses in his combustion training class that I have attended and would HIGHLY recommend taking.

DAM:

Dirt (or rust)
Alignment
Mechanical

these are causes of combustion problems that go beyond fuel/air mixture.

By the looks of your readings I think your O2 reading is still too high, should be between 4-6%. You should be able to get it within that range and still have the CO2 under 100, while producing 0 smoke.

for more real good tech advice go here:

oiltechtalk.com or firedragonent.com - both great sites as well as this one.

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Jim_108

combustion tester

After 37 yr in the trade I broke down and bought a combustion tester.(E-Instruments 1000) Figured since I had already "broke the bank" might as well get a smoke tester.
With all the new high eff. equipment on the market I just could not continue eyeballing it anymore. I know it was just a matter of time before I get in trouble. Brought this stuff home and decided to test my own oil fired boiler (Ultimate PFO-4) I installed a new nozzel (1gph @ 80B) and a new filter.
Here is how it went:
I started with the smoke test. I moved the air shutter closed until the paper was black then moved it slowly back til it tested zero smoke. After that I started with the new combustion tester(set to #2 oil) At first the co2 was at 11.5%. Even though I am not sure where it is supposed to be I desided to adjust the air shutter open til I got to 10%.
When I got a steady 10% co2 I printed out the rest of the info o2= 7.4%
co2= 10.1%
Exc. air= 51.16%
gas temp= 504.5F
air temp= 75.0F
diff. temp= 429.5F
eff. net= 81.1%
loss net= 18.9%
Co= 117 ppm
What am I looking for? Should my co2 be higher? How do the other readouts look.
I would rather look like I don't know what I am doing here then on a job with a customer standing there.
thanks
Jim

dana p._2

combustion tester

not to be a smart ~@*$#. if youv'e been eyeballing combustion tests for 37 yrs. you don't need any advise

Paul S_3

combustion test

you want to try to get the most co2 without having smoke in the fire....[to increase co2 close air shutter]

Dan H

Minnesota code states-
Carbon Monoxide not greater then .04%
Carbon Dioxide between 8 and 13%
Oxygen between 4 and 10%

Jim_108

Dana probably before your time? but on oil we would look at the flame and adjust the air until it was just starting to turn orange then go outside and check for smoke. It always worked ok. The main reason I wanted the tool is for the cond/mod gas equipment.
Is my co to high at around 100ppm? How do I convert ppm to %?
Thanks Jim

Steamhead (in transit)

What was your

overfire draft reading?

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Unknown

You want your CO

air free under 100. The requirement for .04% is an ANSI Standard and is too high it should be changed. To convert PPM to % divide PPM reading by 10,000, example .04% is 400 PPM, 100 PPM is .01%.

Zero smoke is not always the thing to look for as you can have zero smoke and be making high CO.Three readings to watch are CO, O2 and you net stack temperature. Increasing air will lower CO2 and typically cool the flame which will give higher CO so air adjustment after setting pressure and nozzle size is critical. The lower the excess air the higher the efficiency.

You have different ultimate CO2 for different fuels so each one will give different readings for gas it is 11.7%, oil is 15 etc. A good reading with gas is 9.5% CO2 and 5% O2. With Mod/Con systems follow manufacturers instructions for settings they are usually in the I and O manual.

Steamhead (in transit)

Congratulations

for moving into the 21st Century. After a while you will wonder how you got by without the analyzer. I still remember what an eye-opener it was when I used mine for the first time!

If you don't test, you're guessing!

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Jim_108

Is Tim saying that since my co is 117 I should reduce my air and bring the co under 100 which will bring my co2 up?
Won't that make my flame smokey and soot up my boiler? Right now the smoke paper is completely clean. If I set the air to say #1 or #2 will the boiler stay clean. If thats the case I could probably get my eff up to 86% or higher.

I own several houses in the area and tested an old Glow Core boiler I installed about 16 yr ago that was running at 96% eff.

I would say this is one of the top ten coolest tools I have bought. It sure will feel good walking away from jobs knowing the equipment I just worked on is running as corect as possible.
Thanks
Jim

Steamhead (in transit)

Before doing anything

with the air, you'd want to know what your draft is. This will affect pretty much every other reading you get. I'm not familiar with your analyzer, but almost all such units can measure draft.

That CO reading is high, as Tim and others have said.

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Jim Davis

Oil Numbers

CO2 is just a calculation not a measurement. O2 should be between 4%-6%. CO should be under 100ppm at all times. Need to know CO at Light-Of & Shut-Down also. Both should be under 100ppm. Normally when CO is above 100ppm there is a mechanical problem beyond fuel/air adjustment.

tom_49

Jim,

Could be a DAM problem!

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Jim_108

Tom What is DAM

Steam I was back out in the boiler room this morning and adjusted the air open slightly. My analyzer is a greenline UniGas 1000 BTU. I chose this unit beacause it is good for commerical or residental. It set me back a liile over 1100$.

As for this morning tests as I said I introduced a liile moreBA air. My new readings were as follows:

o2= 7.6%

co2=10.2%

Exs. air 53.15%

gas Temp= 490.8F

air Temp= 72.6F

Diff. Temp= 418.2F

Eff. Net= 81.3%

Loss. Net= 18.7%

CO= 73 ppm

Draft= .62hg

thanks


Jim

dana p._2

combustion tests

yes before my time . 21yrs and counting for me. also have done that in a pinch when the batteries die,and out of them also. start with your draft first-.02 to -.04 at breech. stable draft, stable flame. then close the air band down TO PRODUCE A TRACE OF SMOKE ON THE TEST PAPER.at that point run a test with your analyzer. this is what i call the point of no return.( closing the air band down produces more smoke). at this point take a combustion reading with your analyzer and adjust your air band setting 1-1.5% co2 open

A.J.

burner set-up

Beckett recommended cutting back on the air till you get a number one smoke. Take a CO2 & O2 then and knock down your CO2 down by 1.5% by adding excess air. Recommended readings for CO2 are 10% - 12% & O2, 4% -6% but I have had a higher readings on CO2 depending on the appliance. My Beckett AFG is running now @ 13.1% CO2 for three years now. We usually see excess air around 30%- 35%. Follow up by checking your draft and your good. It is all right there in the install manual.

Jim Davis

Not sure how your stack temperature came down when you added air, it should go up unless the water temperature was much lower. Are you firing the boiler at its maximum capacity? Flue temperature is more in line for gas on a boiler. What is your pump pressure? Still would like to know what the CO at Light-Off and Shut-Down are.

Tom was right-looks like a DAM problem-alignment of the drawer assembly, low pump pressure

Steamhead (in transit)

Draft looks way too high

assuming that reading was taken in the stack.

Here are the burner setups for the PFO-4, from the I&O manual:

PFO-4


0.65 AFG 14619201 Delavan .60 X 80 A 140 F0 Fixed Yes 10.0 1.0
1.00 AFG 14619201 Delavan .75 X 80 A 140 F3 Fixed No 10.0 0.0
1.35 AFG 14619201 Delavan 1.20 X 80 B 140 F6 Fixed No 10.0 2.0

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Jim_108

I am beginning to think there is something wrong with my burner or maybe the installation. If I get my co2 up to 11% and the o2 down to 5% my co gos way past 100. Another weird thing that happends is when my o2 goes below 4.9 my analyzer starts beeping an alarm and the o2 reading starts bilnking as if I am doing something unsafe?

Maybe I am misunderstanding where the o2 should end up being. If I hang my co2 around 10% the o2 seems to always be about 7%. That seems to be the best I can get without allowing my co to go above 100. Is it possable my nozzel is to small?

I have been fooling around with this thing all eveing and my house is ablou 90 degrees with the windows open.
thanks

Jim

Steamhead (in transit)

Draft looks way too high

assuming that reading was taken in the stack.

I've attached the initial Beckett burner setups for the PFO-4, from the I&O manual. It's time to go back and check everything. Note to homeowners or anyone who does not have a digital analyzer and the knowledge to use it properly: Don't try any of this. Hire a REAL pro!

They also note:

"All burners fired at an over fire pressure of +0.02” w.c."

and then:

"With chamber fully warmed up, find highest CO2 level at which zero smoke can be maintained. Then add extra air until CO2 falls off about 1%. Final setting should be at least 11% CO2.

If unable to obtain that reading, check for internal oil leaks, incorrect flame retention head or faulty or incorrect
nozzle.

Draft will vary as air is adjusted. It should
be left at as near zero as possible at breeching.

The correct nozzle is the smallest which will do the
job properly. Long continuous runs with minimum
starts and stops conserve the most energy. The
nozzle which provides the highest CO2 with the
least smoke for a particular application is always
recommended."

and then:

"A ¼” diameter slot is provided in the inspection
cover plate to take draft readings in the combustion
chamber. A ¼” diameter hole will be required in the
flue pipe between the boiler and barometric damper
(if used) to take draft, CO2, smoke and temperature
readings.

Adjust air shutter on oil burner to obtain
a “trace” of smoke. Measure CO2 at this point. Increase
air adjustment to lower CO2 approximately
1%.

Check to insure minimum -.02 w.c. “overfire”
draft, and zero smoke. If -.02 w.c. “overfire” draft can
not be maintained, changes and/or modifications
may be required in the venting or the chimney."

They still say to look for a trace. It's better to find true zero smoke and then go down 1%. That way if the oil-air mix changes, you have some headroom.

Some of this is contradictory, but your draft appears to be too high. It should be close to zero at the breech and positive 0.02” or at least -0.02" over the fire. So you may be losing retention at the burner head. Are you firing that thing into an old chimney that was built for a coal-fired boiler? Is there a barometric on the stack? If so, what size is it?

Now that you have the proper equipment, increasing your level of knowledge is the next step. Get to George "Firedragon" Lanthier's and Tim McElwain's classes as soon as you can.

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Jim_108

Jim Davis, The co on start is usually 30 or so then as the burner is running it slowly rises. If I try to get my o2 down the co will rise above 100 in short order.
Thanks

Jim

Jim_108

Mr. Steamhead, Draft reading I posted befro was a typo it is .62. I think you have (as usual) arrived at the problem. I installed this boiler about 20 yr ago when I moved into this house. At the time it was the most eff oil fired boiler. I don't remember why but when I installed it I used a 5" stainless steel single wall liner inside my enclosed brick chimney. At the wall I continued with5" pipe then at the boiler I installed a 5 to 6 reducer cause the boiler came with a 6" flue outlet. I think the idea was to size the nozzel to the heat load of the house and also use a smaller flue ie 5" instead of 6". The max firing rate for this boiler is 1.25gph. Since I was usuing the 1gpm nozzel the 5" flue should be ok. Maybe this is why I am getting too much draft? There is no damper on the connector to the chimney could that help If I instal one?
thanks
Jim

Jim_108

I consider myself lucky that my burner is not burning correctly. What better way is there to figure out how to use my new combustion analyzer. If this had happened out in the field I would be very frustrated by now. It sure is warm in here....
Jim

Steamhead (in transit)

Is 1 GPH

the nozzle rating, or the actual firing rate? The pump pressure is speced at 140, so to get 1 GPH at that pressure you'd use a 0.75 x 80°A..... an A, not a B.

And I think you're in the market for a draft regulator. Use a 6-inch, it will fit on a 5-inch pipe and give you better regulation. Try to get the Field type M rather than the RC, it's a bit more stable. But the RC is OK if that's all you can get.

I wouldn't have reduced the flue diameter, but there it is.

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Steamhead (in transit)

You are following

a time-honored tradition in our industry- trying new equipment and techniques in our own homes first.

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