Boiler Combustion efficiency testing


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Old 05-13-07, 09:59 AM
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Thumbs up Boiler Combustion efficiency testing

Hi all-
I recently bought an UEI C75 combustion analyzer for my home use. Nice considering it's made in the UK. Normally british electronics would be considered a POS, historically speaking. Not too many UK TV manufacturers etc. You know what I mean. They seem to deal more with industrial electronics like level controls transmitters, chart recorders etc. So I'm saying it's an okay unit and so far it works quite well.

My first test.

My New Yorker FR-122W boiler. IIRC, it hasn't been tested since I had a contract the first year I bought the house. The first tech was 19 years old and did the filter nozzle and boiler cleaning. After that, the start-up would produce a pop noise, so after a few days, I called back and requested an experienced tech. After all, this was a 1 year Gold boiler contract with fuel delivery for one year. The second tech was about 60 years old and a professional. He redid the whole burner setup, adjusted the electrodes, oil pump to 100PSI and smoke test. Next he tuned the boiler air intake and finally a smooth quiet burning Becket AFG. I was impressed. That lasted for quite a long time after a couple of bottom barrel filter and nozzle swaps, it's time to do it myself. The professional tech did the work back in Fall of 2000. Since then, I have not seen anyone perform this test with a printout. I only had two other techs here since then including my last redo of the filter, screen and electrodes.

I decided to draw water into the bath tub to start the process:

Turned on the C75 to get ambient temperature reading before testing. The meter is set to light oil and efficiency calculations are based upon British Standars BS845.

Boiler eventually kick in and I let it go for a minute:

Next I found the flue test hole right after the boiler and before a 90deg bend and the draft controller. Probe length right in the middle of the flue pipe.

I hit the pump on button and away it went. Here is the first test results so please no flames. Remember this hasn't been adjusted since the year 2000.

Once I reached the highest flue temp I saved the reading in memory.

Here they are:

CO 20 ppm (actual measured)
CO2 12.9% (calculated)
O2 3.5% (actual measured)
Ambient Temp 72Deg F
Delta Temp 355Deg F
Flue Temp 427Deg F
Unburned fuel losses 14.6%(calculated)
Efficiency(gross) 85.4%(calculated)
Excess Air 20.1%(theoretical amount of air in excess of level needed to completely burn fuel.)

Thanks guys. BTW, the electrodes are original since I moved in. They might have been replaced by the pro tech back in 2000, not sure. I have a new set waiting to be put in when I get the rest of my equipment.
I'm still shopping for a smoke pump, draft meter, oil pressure gauge, vacuum gauge. I also eventually want to add a TigerLoop filter combo but that can wait.
 
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Old 05-13-07, 04:43 PM
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Thumbs up Test Results

Results look real good. CO2 is a tad high but with a CO of only 20ppm, I would only like to see a smoke & draft numbers. Other than that, I'd kiss it softly & say nice things to the boiler & burner.

Pressure & vacuum gauges can be had at a plumbing or HVAC supply house. You would only need to adapt from whatever thread is on them (usually 1/4" NPT) to whatever you want. On my pressure gauge, I have it adapted to 3/16" flare so I can put it on the pump discharge line. For the vacuum, you can install a short 1/4" nipple in place of the flare adaptor on the pump inlet followed by a 1/4" tee. Put the flare adaptor on the run of the tee & the vacuum gauge on the branch. By doing this, you now have a gauge you can look at anytime. If you want to, the pressure gauge can be installed in the gauge port of the pump. I don't like installed pressure gauges since I saw one leak one time.
 
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Old 05-14-07, 07:01 AM
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combustion test and pressure gauge info thanks...

...Grady-
I appreciate your experienced information. As you well know this is quite new to me, but I'm quite technical in my vast experience so it's great to get good intel that this site provides. I also noticed the CO2 was about 1% too high. I think it should be like 10-12% IIRC. The CO is surprisingly low but now that I understand the concept regarding perfect combustion and ideal combustion, it's quite interesting. After reading and researching CO, I was amazed that originally CO detectors were sensitive enough to go off at a certain amount. But because they were so senstive, the public cried out and a new set of standards came out so detectors will only go off if the CO is incredibley high. the point that the long term effects would eventually kill you anyway, so you have a detector and your sucking in CO just under the radar that can produce cancer and other diseases. Tragic. The C75 is worth every penny IMO.

Once I get a draft meter and smoke pump, I'll accommodate you.

The guage information is great, thanks. I also like the fact that you can check vacuum to determine if the filter needs replacing. Yes, I have an old Suntec AV2A-7116 and a NIB Suntec AV2A-7116-7 for backup.

More info to come...
 
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Old 05-14-07, 05:27 PM
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Vacuum/CO Detectors

Many of the spin on filters have a vacuum gauge port right on the filter head, just FYI.

There is a CO detector on the market, available only thru HVAC & other professional service people, which will detect CO at far lower levels. Because of this increased sensitivity, it is not UL listed. If I remember correctly, there is information about them on Bacharach's web site (maybe in the "Training Room").
 
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Old 05-15-07, 07:33 AM
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Thumbs up Low level CO and efficiency chart and more

Grady, The bacharach site is full of surprises. The link to the non UL listed goes to the coexperts.com site which has this monitor(nighthawk). Bookmarked, tnx.

My readings were very close to the efficiency chart on the bacharach site.

The C75 is sturdy unit. I'm pretty happy with it's ease of operation.

I will follow-up when I finally get more front-line equipment like the smoke test kit and draft guage.
 

Last edited by hexonx; 05-15-07 at 07:34 AM. Reason: typos
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Old 05-15-07, 08:02 AM
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Interpreting test results as per Bacharach

This is a great link to understand the results. The troubleshooting techniques using the test results is an excellent read.

http://www.bacharach-training.com/Interpretation%20of%20Test%20Results/interpreting_test_results.htm
 
 

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