oil burner eff testing

taz

can you tell me the variables in the eff testing numbers..

co?

co2?

stack temp?

 etc.....

meplumber

How do you mean?

There is a delicate relationship between CO2, Excess Air, and Smoke. As CO2 increases, Excess air must decrease. As a result, smoke increases as well.



In Stoichiometric combustion theory, you should be able to achieve 22% Excess Air, 14% CO2 and 0 CO (Or something like that, dependent on whose class you take.)



In the real world, 12% CO2 in a warm basement, with 28 - 30% excess air and CO under 5 ppm is a good place to start.



As for stack temp, 325 deg is considered the minimum for a masonry tile lined chimney. Metal liners vary by manufacturer.



What else were you looking for?

taz

new guy

I'm new to the eff testing on oil burners and was wondering what are good numbers. I understand that it varies alot. Just for instance i did a test and the stack temp was close to 600. Wasnt sure if the oil company over fired the nozzle or was getting to much air ?. curious on the variable in numbers.....



thanks



walter

meplumber

Stack temps vary

Boiler type effects stack temp more than any other variable. The old pin boilers ran very high stack temps, some as high as 700 deg. The newer 3 pass boilers run much lower, usually in the area of 325 deg.



Try and get your hands on the Oilheat Technician's Manual from NORA or a Beckett Burner Guide. Both have an excellent section on combustion. I use those sections to train new guys.



Good Luck.

nugs

A testing we will go

What is the make and model of the appliance you are testing?  Stack temps. of 600 and higher are not uncommon in vertical steel tube and cast iron single pass boilers.  In the old days when there were still a lot of coal conversion boilers around we used to put bricks in the passage ways to slow down the combustion gasses which could get to 900 degrees or so without baffling.  Stack temps are related to a host of things from the firing rate, draft, heat exchanger design, flue size and steady state run time.  Efficiency testing is a bit of a balancing act with older equipment because when we try to maximize Co or O2 we can often create a situation where when we leave the appliance, it is performing well but any change in the air setting or the nozzle, oil and air temperature and draft can cause the burner to begin to produce smoke and smoke will drastically reduce efficiency and lead to a service call back.  I like to err on the side of a clean fire.  NORA's Silver Certificate book is a great place to start the learning process and there is a wealth of such information on their web site also.

nugs

A testing we will go

What is the make and model of the appliance you are testing?  Stack temps. of 600 and higher are not uncommon in vertical steel tube and cast iron single pass boilers.  In the old days when there were still a lot of coal conversion boilers around we used to put bricks in the passage ways to slow down the combustion gasses which could get to 900 degrees or so without baffling.  Stack temps are related to a host of things from the firing rate, draft, heat exchanger design, flue size and steady state run time.  Efficiency testing is a bit of a balancing act with older equipment because when we try to maximize Co or O2 we can often create a situation where when we leave the appliance, it is performing well but any change in the air setting or the nozzle, oil and air temperature and draft can cause the burner to begin to produce smoke and smoke will drastically reduce efficiency and lead to a service call back.  I like to err on the side of a clean fire.  NORA's Silver Certificate book is a great place to start the learning process and there is a wealth of such information on their web site also.