B vent leaking from seam in pipe?

Gordy

That will work with a metal blade. So will a grinder with cut off wheel. Sparks though bad in the wrong environment......

ChrisJ

Gordy said:

That will work with a metal blade. So will a grinder with cut off wheel. Sparks though bad in the wrong environment......

I want to see you cut an 8" circle with a grinder and a cutoff wheel.

Seriously.

Gordy

No problem!

Gordy

I can do it with a Skil saw too. In wood.

Fred

@ChrisJ , I have one of these (Malco adjustable cutting tool) that I bought when I put my duct work in for my central air. It uses a regular drill and cutting bits. It does an excellent job! Buy a few cutting bits for nice clean cuts.
https://www.amazon.com/Malco-HC1-2-Inch-12-Inch-Accessory/dp/B000289542

BobC

That looks like a neat tool and not all that expensive.

Bob

Fred

BobC said:

That looks like a neat tool and not all that expensive.

Bob

It really is a bargain for the nice round, clean cuts in a couple minutes.

EBEBRATT-Ed

better go with ear plugs with a jig saw youll get shaken to death. Yikes 20 gage?? that's pretty heavy no wonder your hurting.

You can buy a MALCO TSHD attachment for a drill to cut sheet metal with it's about $80.

ChrisJ

Interesting looking tool, does it work on round pipe? My trunk is 14" round.

@EBEBRATT-Ed Yeah, a friend of mine made up the return and supply plenums for me as well as a 14x30 ceiling box. His shop mainly uses 20 gauge so it was my only choice.

All of the round pipe is 28 gauge.

This is the supply plenum I finished today. Well, I still need to drill for and install the 1/8" barbed fitting in the top for the Magnhelic. Other than that, it's finished.







My first ever flex connector. It's not perfect, but it works. The piece of wood is holding the flap shut while the silicone dries.

Fred

I would say you want to cut your holes in that 14" trunk before you snap the seam together.

Gordy

How many band aids?

Mark Eatherton

Chris, did you block off the existing dilution air inlet on the fixed draft hood on the boiler? If not, the barometric damper is useless...

ME

ChrisJ

Mark Eatherton said:

Chris, did you block off the existing dilution air inlet on the fixed draft hood on the boiler? If not, the barometric damper is useless...

ME

Hi Mark,

Me and Jstar did back in 2015 when we installed the barometric. Doing so caused the O2 to go through the roof, even with 5" manifold pressure (stock is 3.5") I think we were seeing 13 or 14% O2 while holding the barometric wide open.

Because of this, we put the original drafthood back on and just left the barometric because it seemed harmless. With the original drafthood in place the O2 dropped back to something more reasonable, 6-7% or so with the correct manifold pressure.

Mark Eatherton

Having done hundreds of this type of conversion, I can tell you that you have to block off the opening on the fixed draft hood, then adjust the barometric to -.02" W.C. on the inlet side of the damper. I've used this numerous times to eliminate situations exactly like yours, sweating stacks. Combustion numbers should be perfect at that point (-.02 draft between baro and appliance).

You can and probably should wrap the B vent with fireproof (un bound fiberglass) insulation where it passes through the attic if the attic is not being a part of the conditioned space. Wrap it with aluminum if you are worried about the glass fibers floating around.

ME

ChrisJ

Mark Eatherton said:

Having done hundreds of this type of conversion, I can tell you that you have to block off the opening on the fixed draft hood, then adjust the barometric to -.02" W.C. on the inlet side of the damper. I've used this numerous times to eliminate situations exactly like yours, sweating stacks. Combustion numbers should be perfect at that point (-.02 draft between baro and appliance).

You can and probably should wrap the B vent with fireproof (un bound fiberglass) insulation where it passes through the attic if the attic is not being a part of the conditioned space. Wrap it with aluminum if you are worried about the glass fibers floating around.

ME

Jstar said he had done many as well, he didn't understand why this boiler behaved the way it did. He spent quite a while messing with it before giving up.

I can tell you adjusting the barometric doesn't matter because like I said, we held it wide open and it wasn't dropping the draft enough and it wasn't that cold out. Too much air was going through the boiler. This was also with a 7" barometric on a 6" pipe.


Jstar's guess was it's because an EG-40 like mine, is really setup to be an EG-45 with an extra burner and they used the baffled drafthood to cheat. By eliminating the drafthood the burner tray just gets way too much O2.

The EG-45 is the same exact setup, but a different drafthood and an extra burner tube. The rest is exactly the same.

Mark Eatherton

If one (baro) wasn't enough, then you needed two. As long as all of the burners are intact, and no orifices are plugged off, it should still work. 60' is a very tall stack and can achieve significant draft, which pulls excess dilution air in, causing the flue gasses to cool off and condense.

ME

ChrisJ

Mark Eatherton said:

If one (baro) wasn't enough, then you needed two. As long as all of the burners are intact, and no orifices are plugged off, it should still work. 60' is a very tall stack and can achieve significant draft, which pulls excess dilution air in, causing the flue gasses to cool off and condense.

ME

30 foot, not 60.
This is a standard 2 story single family home.

I am curious though, how is having multiple barometrics not allowing the same amount of dilution air in? Either you let the dilution air in, or your draft is too high through the boiler, no?

JUGHNE

Don't know what you are doing for duct insulation, but I cut the holes in the box, insulate it and then cut the hole in the insulation a little small , then put the take off in. Easier install of insulation with tight fit on the TO and less seams later.

Tinman

Mark or Chris - Help me understand why I barometric damper would ever be considered in this specific application - Atmospheric burner with a draft hood, standard stack height, on the east coast, properly sized vent.

ChrisJ

> @Stephen Minnich said:
> Mark or Chris - Help me understand why I barometric damper would ever be considered in this specific application - Atmospheric burner with a draft hood, standard stack height, on the east coast, properly sized vent.

I can't. We did it just to see if we could squeak a little more efficiency out by regulating the draft and increasing the manifold pressure to lower the excess o2. But it didn't work.

Mark Eatherton

Steve, Chris et al, the fixed draft relief hoods on every gas fired appliance are a piece of crap as it pertains to "regulating" draft on a substantial chimney. As such, it does a terrible job of "regulating" draft. It does just enough a good job on the test bench, that it is an accepted method of maintaining negative draft within the combustion chamber, which is very important. Without it (negative draft), you get spillage and people can get sick and or die. When you truly "regulate" the draft on a naturally vented appliance, you are drawing the perfect amount of air into the combustion process, and the numbers get close to stoichiometric burn (ideal burn) conditions as can be achieved under the various conditions the stack and appliance will see.

Steve, as a contractor, I'd strongly suggest that you join NCI and see Jim Davis live. He will clear it up for you real quick, and when you come away, you will have a much better understanding of all the things that affect efficient combustion. And if, God forbid, you ever get called onto the proverbial carpet for having modified one of these appliances, they will back your testimony in court.

Chris, post your question up in the CO section and get the Guru of Partially Burnt BTU's (Jim Davis) opinion. He also has a trick about placing a restrictive orifice at the appliance to regulate draft, but I've been away from that part of the industry to the point that I don't remember all the requirements for application. I did it once on an appliance that had a 15 story stack, and cut their fuel use by 30%. Then we installed a bunch of modcons and cut their fuel bills an additional 30%.

A word of caution is required at this point. ANYONE modifying a gas appliance is biting off a large chunk of liability connected to the appliance. If anything goes wrong, you will be holding the bag of liability. Modifications done improperly, can result in loss of life or property... If you modified it, the manufacturer is no longer liable. You are.

ME

Tinman

Thanks Mark. Your explanation makes perfect sense and I understand the draft on these appliances can be less than ideal.

But, in the very real world of risk versus reward, I'm going to stick with the draft hood as is. Contractors, like myself, have enough to deal with without potentially opening up a can of worms (liability, exposure) that could make me a former contractor. As long as the stack on a Category I appliance isn't condensing or spilling and is within "normal" draft range, I'm good with it.

That said, I'd love to take a class by Jim Davis.

Mark Eatherton

Stephen Minnich said:

Thanks Mark. Your explanation makes perfect sense and I understand the draft on these appliances can be less than ideal.



But, in the very real world of risk versus reward, I'm going to stick with the draft hood as is. Contractors, like myself, have enough to deal with without potentially opening up a can of worms (liability, exposure) that could make me a former contractor. As long as the stack on a Category I appliance isn't condensing or spilling and is "normal" draft range, I'm good with it.



That said, I'd love to a class by Jim Davis.

The appliance manufacturers really don't (in most cases) have the consumers best interests in mind as it pertains to operating costs. Jim's class is WELL worth the time and money spent.

ME

ChrisJ

@Mark Eatherton Jim Davis was actually helping me before we did the modification. Sadly, me being me, I didn't want to call him and bother him while we were doing the testing.

Don't take this as me questioning you, it's more of me trying to understand what I may not. This is similar to me going up on my roof, it's out of my comfort area therefore I don't mess with it. But, I am curious.


I do not see how a barometric can perfectly regulate draft through an appliance that does not have any means to regulate the air going into it. The reason I say this is obviously the draft must change, otherwise the door on the damper would never open more. Even with the drafthood in place, I measured upwards of 0.06" with the damper working at the flue connector of the drafthood.

I'm going off of memory now from fall of 2015, but if I recall that barometric was calibrated for 0.01" of draft. Mine was perfectly plumb and installed as close to the appliance as possible. 0.06" may not seem like much, but it's six times the initial draft. The drafthood on my EG-40 does not appear to change that much, I say this because with it blocked I could hear the difference from the burner. It had more of a roaring torch like sound. I've never heard that with the drafthood functioning.

Going from 0.01" to 0.06" seems like a pretty big increase to me, and it makes sense. If the draft was 0.01", the door would have nothing to pull it open. Six times the draft on a natural draft appliance means six times the air going through the burner. And this was with the damper door not even open that much, I can't imagine how much draft it would need to be held 75% open. 0.1"? 0.5?"

I had asked Jstar about putting in a fixed damper between the boiler and the barometric, but he didn't like that idea because it could be tampered with. Obviously I wouldn't mess with it, but I suppose there's no way to know what anyone down the road would do.

Tinman

@Mark Eatherton I understand your point about operating costs but if one of my customers want to upgrade from cast iron to a Lochinvar KHN to improve that, count me in. : )

Tinman

Again, risk vs. reward.

ChrisJ

Hatterasguy said:

ChrisJ said:

Going from 0.01" to 0.06" seems like a pretty big increase to me, and it makes sense. If the draft was 0.01", the door would have nothing to pull it open. Six times the draft on a natural draft appliance means six times the air going through the burner. And this was with the damper door not even open that much, I can't imagine how much draft it would need to be held 75% open. 0.1"? 0.5?"

It would appear that the authority of the door is woefully inadequate as compared to the potential draft.

The action of the door is not anywhere near close to the required movement necessary to properly regulate the draft.

You would need a larger barometric or additional units to get closer to the desired result.

Also, realize that we make the assumption that this swinging door can magically maintain a specific draft upstream when, in reality, such a crude device with a non-linear relationship between opening and airflow will probably not achieve a perfect result.

And this is with a 7" damper on a 6" pipe. From what I understand, SOP is to install a 6" damper on a 6" pipe and only go to one size bigger if required.

Tinman

@Hatterasguy - Did we just agree on something? : )

ChrisJ

It's bound to happen.

Mark Eatherton

Stephen Minnich said:

@Mark Eatherton I understand your point about operating costs but if one of my customers want to upgrade from cast iron to a Lochinvar KHN to improve that, count me in. : )

Agreed Steve, but not every customer has piles of money laying around looking for a modcon boiler to give it to. I keep this one in my back pocket for those aging in place...

ME

Mark Eatherton

ChrisJ said:

@Mark Eatherton Jim Davis was actually helping me before we did the modification. Sadly, me being me, I didn't want to call him and bother him while we were doing the testing.

Don't take this as me questioning you, it's more of me trying to understand what I may not. This is similar to me going up on my roof, it's out of my comfort area therefore I don't mess with it. But, I am curious.


I do not see how a barometric can perfectly regulate draft through an appliance that does not have any means to regulate the air going into it. The reason I say this is obviously the draft must change, otherwise the door on the damper would never open more. Even with the drafthood in place, I measured upwards of 0.06" with the damper working at the flue connector of the drafthood.

I'm going off of memory now from fall of 2015, but if I recall that barometric was calibrated for 0.01" of draft. Mine was perfectly plumb and installed as close to the appliance as possible. 0.06" may not seem like much, but it's six times the initial draft. The drafthood on my EG-40 does not appear to change that much, I say this because with it blocked I could hear the difference from the burner. It had more of a roaring torch like sound. I've never heard that with the drafthood functioning.

Going from 0.01" to 0.06" seems like a pretty big increase to me, and it makes sense. If the draft was 0.01", the door would have nothing to pull it open. Six times the draft on a natural draft appliance means six times the air going through the burner. And this was with the damper door not even open that much, I can't imagine how much draft it would need to be held 75% open. 0.1"? 0.5?"

I had asked Jstar about putting in a fixed damper between the boiler and the barometric, but he didn't like that idea because it could be tampered with. Obviously I wouldn't mess with it, but I suppose there's no way to know what anyone down the road would do.

Chris, the fire in the fire box creates the upward flow (hot fluids rising) of flue gasses. If the "draw" of the connected chimney is too significant, as you found out through experimentation, then the air being drawn into the combustion process is WAY too significant. The roar you heard was probably the flames lifting off the face of the burner, and that is not good. In your burner, there are two required airs' Primary, which is the gas that is mixed with the fuel at the face of the burner, and secondary air, which is the air that flows around the burner and allows the primary air and fuel to burn completely. It is a delicate balancing act.

It is all set up around maintaining a -.02" draft over the fire. Anything less will have issues (excess Co2 and CO being produced), as will anything more (excess air being drawn though the combustion process). More is bad because it is carrying heat up the stack and not allowing a good and complete combustion (Stoichiometric burn). In your case, due to the lack of draft regulation, the third air kicks in and is the one causing your stack to sweat. That air is called draft dilution air. By regulating draft, you only let in the air necessary to maintain perfect draft, and are only drawing in the required air for a good and complete combustion.

It's complicated. The amounts of counter weights necessary are dictated by all of the variables, and in most cases, are significantly less than most people think. They think that more is better, and God forbid, having the hole sitting there wide open causes a lot of consternation. But it is what is necessary to relieve the excess draft being caused by the tall chimney.

In a properly adjust barometric damper, when the appliance first starts, the baro will be closed. The stack is establishing draft. Once draft kicks in, the damper blade will open just enough to maintain the -.02" WC setting. It may open or close more depending upon all the variables. Once the appliance satiates, the damper will remain open for a short period while the draft dissipates, and will then close. In most cases, unqualified personnel think the damper is supposed to be closed so it doesn't spill carbon monoxide, and they throw WAY too much weight on the chain, keeping the draft relief closed, compounding the problems of excess air being drawn through the process. I noted in your picture that you have the spill switch in place. Wise move on your part.

Another problem, is that the appliance manufacturers quit building the burners such that a person could make adjustments to the primary air. Not much a person can do about that, except adjust the draft to the minimum required and draw less air into the burner tube.

You should have called Jim. He'd be telling you the same thing I'm telling you. I know this because I have taken his class a couple of times, and find myself learning more each time I attend. If the US listened to Jim and applied his teachings, we'd have no problem reducing our consumption of fuel by 30%... FACT.

Also, draft measurements have to be done between the draft regulator and the fire. Impossible to do with a fixed hood that most appliances have. Especially with no adjustments. Draft pressure should NOT be tested downstream of the regulator. IIWII, and the regulators job is to reduce dilution air being drawn in at that point. Like I said, a delicate balancing act.

ME

ChrisJ

Mark Eatherton said:

ChrisJ said:

@Mark Eatherton Jim Davis was actually helping me before we did the modification. Sadly, me being me, I didn't want to call him and bother him while we were doing the testing.

Don't take this as me questioning you, it's more of me trying to understand what I may not. This is similar to me going up on my roof, it's out of my comfort area therefore I don't mess with it. But, I am curious.


I do not see how a barometric can perfectly regulate draft through an appliance that does not have any means to regulate the air going into it. The reason I say this is obviously the draft must change, otherwise the door on the damper would never open more. Even with the drafthood in place, I measured upwards of 0.06" with the damper working at the flue connector of the drafthood.

I'm going off of memory now from fall of 2015, but if I recall that barometric was calibrated for 0.01" of draft. Mine was perfectly plumb and installed as close to the appliance as possible. 0.06" may not seem like much, but it's six times the initial draft. The drafthood on my EG-40 does not appear to change that much, I say this because with it blocked I could hear the difference from the burner. It had more of a roaring torch like sound. I've never heard that with the drafthood functioning.

Going from 0.01" to 0.06" seems like a pretty big increase to me, and it makes sense. If the draft was 0.01", the door would have nothing to pull it open. Six times the draft on a natural draft appliance means six times the air going through the burner. And this was with the damper door not even open that much, I can't imagine how much draft it would need to be held 75% open. 0.1"? 0.5?"

I had asked Jstar about putting in a fixed damper between the boiler and the barometric, but he didn't like that idea because it could be tampered with. Obviously I wouldn't mess with it, but I suppose there's no way to know what anyone down the road would do.

Chris, the fire in the fire box creates the upward flow (hot fluids rising) of flue gasses. If the "draw" of the connected chimney is too significant, as you found out through experimentation, then the air being drawn into the combustion process is WAY too significant. The roar you heard was probably the flames lifting off the face of the burner, and that is not good. In your burner, there are two required airs' Primary, which is the gas that is mixed with the fuel at the face of the burner, and secondary air, which is the air that flows around the burner and allows the primary air and fuel to burn completely. It is a delicate balancing act.

It is all set up around maintaining a -.02" draft over the fire. Anything less will have issues (excess Co2 and CO being produced), as will anything more (excess air being drawn though the combustion process). More is bad because it is carrying heat up the stack and not allowing a good and complete combustion (Stoichiometric burn). In your case, due to the lack of draft regulation, the third air kicks in and is the one causing your stack to sweat. That air is called draft dilution air. By regulating draft, you only let in the air necessary to maintain perfect draft, and are only drawing in the required air for a good and complete combustion.

It's complicated. The amounts of counter weights necessary are dictated by all of the variables, and in most cases, are significantly less than most people think. They think that more is better, and God forbid, having the hole sitting there wide open causes a lot of consternation. But it is what is necessary to relieve the excess draft being caused by the tall chimney.

In a properly adjust barometric damper, when the appliance first starts, the baro will be closed. The stack is establishing draft. Once draft kicks in, the damper blade will open just enough to maintain the -.02" WC setting. It may open or close more depending upon all the variables. Once the appliance satiates, the damper will remain open for a short period while the draft dissipates, and will then close. In most cases, unqualified personnel think the damper is supposed to be closed so it doesn't spill carbon monoxide, and they throw WAY too much weight on the chain, keeping the draft relief closed, compounding the problems of excess air being drawn through the process. I noted in your picture that you have the spill switch in place. Wise move on your part.

Another problem, is that the appliance manufacturers quit building the burners such that a person could make adjustments to the primary air. Not much a person can do about that, except adjust the draft to the minimum required and draw less air into the burner tube.

You should have called Jim. He'd be telling you the same thing I'm telling you. I know this because I have taken his class a couple of times, and find myself learning more each time I attend. If the US listened to Jim and applied his teachings, we'd have no problem reducing our consumption of fuel by 30%... FACT.

Also, draft measurements have to be done between the draft regulator and the fire. Impossible to do with a fixed hood that most appliances have. Especially with no adjustments. Draft pressure should NOT be tested downstream of the regulator. IIWII, and the regulators job is to reduce dilution air being drawn in at that point. Like I said, a delicate balancing act.

ME

Hi Mark,


The orange arrow points to where Jstar drilled the hole for measuring. We also had one in the elbow as you can see. Also notice, no weights on the chain.





I have a very hard time swallowing barometrics can increase efficiency in a modern cast iron boiler by 30%. I could see 1 or 2%, but 30?

My stack is sweating at the very top when the boiler first fires up and the pipe is cold. It doesn't happen for long, and it doesn't happen when it's actually cold out.

I don't see anything fixing that, the pipe is going to be cold sometimes and it's going to sweat when hot moist air hits it.

Right now, I honestly think it's dripping down the outside and leaking around the storm collar.

I'll find out more tomorrow when the chimney guy comes.

EBEBRATT-Ed

A fixed orfice in the pipe is allowed I believe. Their is a name for it that I cannot recall. Has to be fixed in place with screws.

I have seen techs with combustion testing trying to "thread the needle" all day. What they don't realize is that combustion is constantly changing due to draft, fuel temp, air temp and air density.

I think of it is that your looking for a "safe range" to be in and hopefully the adjustments are such that the burner cannot readily drift into an unsafe range.

was going to suggest 2 barometrics but Mark got in there first but.........

The way I am thinking of this is the dilution air being colder that the boiler flue temp is is reducing the stack temp going up the flue maybe causing the condensation. The flue doesn't care if the low flue temp is coming from being underfired, too much dilution air or low return water temps condensation is condensation

more dilution air and 2 barometrics may make it worse.
I am thinking a restrictor in the flue with a barometric to reduce the volume of flue gas and less dilution air thus making the flue gas warmer to prevent condensation

bob_46

neutral pressure point adjuster

Jack

In the early 90's Brookhaven did an analysis of venting systems for oil. This was shortly after the efficiency standards had changed on gas, with the first requirements for re-lining. The Brookhaven work resulted in Appendix E in NFPA 31, and FYI, anyone who has used it for sizing oil systems has said it was spot on. But that is not what we are talking about here, so...! The one thing the lead engineer on this study said was that the best thing you can do to make a natural draft system operate better is to have an insulated vent connector. In your case Chris that means B-vent from the boiler breech to the vent connector. As well, once the weather gets a bit better I would disassemble the attic vent. Shoot the female end of the pipe with a hi temp RTV silicone and when reassembling, make sure all the seams are up. You will also have an opportunity, at that point to deal with the storm collar. As to the barometric, I'd suggest putting a draft gauge on the system in a cold start and watch how it performs. Seal off the barometric and do the same test. As your boiler has a draft hood connector unless you have excessive draft, the barometric is likely unnecessary. Eliminate 90's in favor of 45's wherever you can. Please keep us posted.

ChrisJ

Looks like the normal pipe insulation we use on steam pipes is rated for up to 1000°F.

B-vents are rated for no more than 400°F input.
That sounds like a pretty good safety factor to me, no?

ratio

I ordered the wrong stuff at work a few years back, now I've got a b vent with 2" fire wrap around it. I'm pretty sure the b vent could melt out of that stuff without causing problems except where it drips down at.

EBEBRATT-Ed

"Neutral pressure point adjuster" thanks @bob

Mark Eatherton

ChrisJ said:

Mark Eatherton said:

If one (baro) wasn't enough, then you needed two. As long as all of the burners are intact, and no orifices are plugged off, it should still work. 60' is a very tall stack and can achieve significant draft, which pulls excess dilution air in, causing the flue gasses to cool off and condense.

ME

30 foot, not 60.
This is a standard 2 story single family home.

I am curious though, how is having multiple barometrics not allowing the same amount of dilution air in? Either you let the dilution air in, or your draft is too high through the boiler, no?

OK, 30 feet is still pretty significant.

It's called a draft regulator because it "regulates" the draft. It controls it to the optimum condition for both proper combustion as well as the amount of dilution air being drawn up the stack. It could even require the placement of the neutral point baffle that Bob introduced.

With your being as particular as you are, I am really surprised that you didn't take this effort to full fruition. Nothing bad will come out of having the boiler set up correctly. Also, Jstar did have the hole drilled in the correct spot.

Elimination of the sweating is a side benefit. Optimizing combustion is it's primary function. In the case where I reduced fuel consumption on the 15 story building, that was an exceptional situation. Normal reductions are are more in the 15 to 20 percent range. Every little bit helps.

ME

ChrisJ

Mark Eatherton said:

ChrisJ said:

Mark Eatherton said:

If one (baro) wasn't enough, then you needed two. As long as all of the burners are intact, and no orifices are plugged off, it should still work. 60' is a very tall stack and can achieve significant draft, which pulls excess dilution air in, causing the flue gasses to cool off and condense.

ME

30 foot, not 60.
This is a standard 2 story single family home.

I am curious though, how is having multiple barometrics not allowing the same amount of dilution air in? Either you let the dilution air in, or your draft is too high through the boiler, no?

OK, 30 feet is still pretty significant.

It's called a draft regulator because it "regulates" the draft. It controls it to the optimum condition for both proper combustion as well as the amount of dilution air being drawn up the stack. It could even require the placement of the neutral point baffle that Bob introduced.

With your being as particular as you are, I am really surprised that you didn't take this effort to full fruition. Nothing bad will come out of having the boiler set up correctly. Also, Jstar did have the hole drilled in the correct spot.

Elimination of the sweating is a side benefit. Optimizing combustion is it's primary function. In the case where I reduced fuel consumption on the 15 story building, that was an exceptional situation. Normal reductions are are more in the 15 to 20 percent range. Every little bit helps.

ME

Well, you have to look at the situation I had.
Jstar was baffled by why my boiler behaved the way it did, it didn't work out the way I thought it would. I was told block the drafthood, throw the barometric in the pipe with the spill switch and adjust the manifold pressure to reduce the excess O2 within reason while keeping CO under 100 and stable.

CO was fine and according to Jstar there were no signs of impingement or anything bad. Just excess O2 was through the roof due to too much draft.

I was tempted to put the EG-45 burner tray and extra tube back in to see what would happen, but really didn't want to.

With what happened, and not knowing enough about it I felt keeping it stock was the smart move. Still do, to be honest. With drafthood blocked numbers were bad, with it stock numbers were good.


You also need to remember, this wasn't something I hired Jstar to repair, there was no problem at the time. This was us messing around to see what we could improve and what effect it would have. When it created a problem we reverted back to stock and went on with our lives.