air fuel ratio

paulmars

air fuel ratio question.

On my oil heater adjusting the air band and shutter I see the flame getting larger and larger as i decrease the air. Set to the smallest air intake the flame is the largest. I never see smoke.

I did a complete tune up last season and noticed this condition, then and again this season.

Your thoughts?

thanks,
paul

ratio

What are the CO₂ & O₂ numbers? Flue temp? Over fire draft? Any CO being produced?

Jamie Hall

Keep in mind that it's not the size of the flame that counts, but the heat. A beautiful big very visible flame is indicative of a lot of unburned or partially burned carbon -- that's what makes the visible flame -- and a relatively cool combustion condition. Not really what you want -- even if there is no visible smoke, there is still more soot on the fire side than you want.

Use the test instruments, not the eye.

EBEBRATT-Ed

A very experienced technician can USUALLY get a flame adjusted by eye and get it close but not with every boiler or burner. Combustion test instruments must be used.

Co is odorless and it can kill and no one can look at a flame and tell you the Co content

Your playing with fire literally.

paulmars

im tired of paying for incomplete turn ups. No one ever even adjusted the damper and the flame was always set with too much air. I reduced the air and the house gets warm literally 3x faster.
I have a manometer. what else do i need?

Jamie Hall

A combustion analyser and the training to use it.

STEVEusaPA

paulmars said:

im tired of paying for incomplete turn ups. No one ever even adjusted the damper and the flame was always set with too much air. I reduced the air and the house gets warm literally 3x faster.
I have a manometer. what else do i need?

You’re exaggerating. There no way your “house gets warm literally 3x faster” from a simple air adjustment. Just impossible.
You also don’t know how much air is required because you have no way to quantify and qualify your statements.

You need a professional with proper tools and training. Maybe interview them before you let them into your home and pay them.
Adjusting air by looking at the flame is pure hackery and could damage your equipment and/or completely soot it up.

After confirming proper nozzle, proper head adjustment, proper pump pressure, a proper analysis is:
-Run burner to steady state, confirmed by flue temperature.
-Adjust draft to manufacturer's specification (over fire and at breech).
-Adjust combustion air to achieve true zero smoke, with a smoke gun.
-Insert analyzer and note CO2. Adjust air band to drop CO2 1 percentage point.

If your tech or company can’t articulate that to you then find another.

paulmars

Reading over the manufacturer's (beckett) "Set combustion with instruments" It says:
Adjust the air shutter/band until a trace of
smoke is achieved.
Increase the air to reduce the CO by 1.5 to 2 percentage points.
Recheck smoke level. It should be Zero

The air handler (carrier) "Combustion Check" says:
"1. A test kit to measure smoke, stack draft, over-fire draft, oil pump pressure, CO2, and stack temperatures MUST be used in order to obtain proper air band setting. Although all of the above measurements are required for optimum setup and efficiency data, the most important readings that must be taken are smoke number, over-fire draft, stack draft, and pump pressure.
2. The proper smoke number has been established by engineer-
ing tests to be between 0 and 1. This degree of smoke emission
is commonly referred to as a"trace′′of smoke. It is recom-
mended to use a Bacharach true spot smoke test set or
equivalent."

tks,pa

paulmars

so if i just set smoke and WC?

paulmars

after complete tune up, of course

Jamie Hall

By complete tune up I presume that you mean new nozzle, check electrodes, clean filters, clean fire side of boiler, then check and adjust with the instruments the smoke, stack draft, over-fire draft, oil pump pressure, CO, CO2, and stack temperatures, then yes...

paulmars

https://www.amazon.com/s/ref=nb_sb_noss_2?url=search-alias=aps&field-keywords=Bacharach+smoke+&rh=i:aps,k:Bacharach+smoke+

massive cost differences above.

paulmars

are their other brands that I can buy too?

Jamie Hall

Those are nice smoke testers. However, none of them are a combustion analyser -- and that's what you need in addition to the smoke tester. You also need a manometer or draught gauge.

Steamhead

@paulmars , where are you located? There really are good burner guys (and girls too) out there, and we may know someone near you.

Koan

Jellis

Have a competent technician perform a combustion analysis and adjust your boiler.
Make sure he leaves a printout of the systems readings and verify they are the proper range.

This is not something to DIY unless you are familiar with these systems, you are correct in worrying about paying a incompetent tech to perform the test.
once you research the proper combustion numbers for your unit you can quiz the tech when he gets there, this should give you an idea if he knows what hes talking about or not.

frankkelly

Great information for setting oil burner and draft etc. Where I come from oil burner techs are reluctant to use any instruments at all. On a service call they remove burner, change the nozzle, don't measure electrode gap or adjust it. They replace the burner, reconnect oil line, change oil line filter,restart boiler without checking oil pressure, peek a the flame through a hole about 2 ins round and adjust the air band while watching the flame. They do not adjust the barometric damper. When I ask what the efficiency is I'm nearly always told it's 85%? They also brush the tubes. This all takes about 30 to 40 minutes start to finish. I'm never satisfied .

STEVEusaPA

30-40 minutes...you shouldn't be satisfied.
I'm easily 1.5 hours with a boiler and swing out door, 2 hours if I have to pull the front of the boiler or the burner.
Usually 1.5 hours+ for a furnace.

paulmars

plz look at these videos of my flame and comment:

https://imgur.com/a/FyTEH7R

and

https://imgur.com/a/QCM7pXf

these are both at the same A/F ratio.

STEVEusaPA

What did you draft gauge, smoke gun & analyzer have to say?
I only look into the fire to see if there is fire and if it is impinging on the target wall or sides.

paulmars

starting new thread https://forum.heatinghelp.com/discussion/169122/exposed-pipe-support-or-draft-inducer-fan/p1?new=1