Combustion Analyzer

velvetfoot

Minister of Fire
Dec 5, 2005
9,973
Sand Lake, NY
You got that right..LOL. They are having problems dialling in my unit without restricting the flue too much (causing smoke spillage) , and controlling input air (EPA regulation)
Yeah, you're dealing with warranty and the company has restrictions on what they can do.
 

wooduser

Minister of Fire
Nov 12, 2018
680
seattle, wa
. The only gauge reading they seem to have any concern with is the one from the Magnahelic. He said once the draft is dialled in to spec , the unit will burn as designed and expected and to meet the EPA guidelines for clean burn.

First, our board Xperts don't actually measure draft, according to them. They eyeball the installation and burning and decide on whether the draft is OK on that basis without actually measuring it. However, they are often interested in stove temperature.

Secondly, that statement from the stove manufacturer sounds like baloney. If the wood is green or the stove operator isn't operating the control correctly, the stove isn't going to work right, even if the measured draft is within specifications. Stoves or flues being partially plugged up with debris might still draft OK, but significantly impair combustion. A defect in the construction of the stove or a broken part might cause a defect in combustion.

Our board Xperts are giving the combustion system they inspect a careful examination, which ought to catch issues such as green wood, broken parts, poor stove operation and such. But a manufacturer that not checking for those kinds of issues seems foolish indeed. The stove isn't the only element of a combustion system, and the stove itself can have problems. Simply measuring draft seems way too simplistic.

Measuring the draft or measuring the stack temperature are both elements of a combustion analysis. Why not do the whole test and get an accurate idea of what is actually happening rather than just assuming everything is fine if something like the draft is OK?

<< and expected and to meet the EPA guidelines for clean burn.>> Yep, we'll just assume everything is OK if the draft is up to spec! How foolish is that?
 

saydinli

Burning Hunk
Nov 6, 2016
233
Near Fergus Ontario
First, our board Xperts don't actually measure draft, according to them
Like the Xperts have said, anyone with enough experience installing/servicing/designing these units will know exactly how the unit is burning just by looking at the fire as it burns. Heck, after 3 seasons of 24/7 burning, I can recognize how the unit is burning and make the necessary adjustments. PE recognized my over drafting fire just from a series of 3 videos I took during the 1st hour of a fully loaded burn. No temp readings were needed, no draft readings were needed, and no CO2 readings were taken. They only needed the Manometer to determine the restricter plate sizing.

But a manufacturer that not checking for those kinds of issues seems foolish indeed
Who said they don't check these things when they come out to check your unit? One of the first things the PE rep looked at was my wood stacks outside and inside my garage and then he checked the door gasket, the chimney, looked for any cracks or broken welds inside the unit ( remember, my issue is excessive draft). If you read through what our Experts on hear always ask are these types of questions as that info will tell you alot about whats going on. No need for fancy gauges to do that.

Secondly, that statement from the stove manufacturer sounds like baloney
You can say what you want, but I'll take the word and advise of a manufacturers 40 years experience in designing and building these units any day.

Yep, we'll just assume everything is OK if the draft is up to spec! How foolish is that?
I would say not very foolish as PE builds some of the best wood burning units out there and I have no reason to believe they don't know what they are doing.

I wouldn't doubt that manufactures use many data points through various sensors and gauges during the R&D phase of designing a stove or fireplace, but I don't see the necessity for them in the field for each and every install. Once the unit is designed to specs that meet EPA and UL requirements, the units will burn as design and expected. The only thing to do in the field is to make sure the manufacturers installation requirements are met and building codes are met. After that it's making sure the customer burns the correct wood properly as per manufacturers recommendation and making adjustments as required.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
18,617
central pa
First, our board Xperts don't actually measure draft, according to them. They eyeball the installation and burning and decide on whether the draft is OK on that basis without actually measuring it. However, they are often interested in stove temperature.

Secondly, that statement from the stove manufacturer sounds like baloney. If the wood is green or the stove operator isn't operating the control correctly, the stove isn't going to work right, even if the measured draft is within specifications. Stoves or flues being partially plugged up with debris might still draft OK, but significantly impair combustion. A defect in the construction of the stove or a broken part might cause a defect in combustion.

Our board Xperts are giving the combustion system they inspect a careful examination, which ought to catch issues such as green wood, broken parts, poor stove operation and such. But a manufacturer that not checking for those kinds of issues seems foolish indeed. The stove isn't the only element of a combustion system, and the stove itself can have problems. Simply measuring draft seems way too simplistic.

Measuring the draft or measuring the stack temperature are both elements of a combustion analysis. Why not do the whole test and get an accurate idea of what is actually happening rather than just assuming everything is fine if something like the draft is OK?

<< and expected and to meet the EPA guidelines for clean burn.>> Yep, we'll just assume everything is OK if the draft is up to spec! How foolish is that?
Ok i never said i dont measure draft i said i rarely do because i usually dont have to. If i feel it is nessecary i will measure it absolutly. Yes we are interested in stove temperature because that is a big factor in how the stove works. It is also effected and effects the draft. You are also only seeing how we help people over the internet. Most people dont have a draft gauge so asking them what their draft is would not be benificial.

That statement from the manufacturer is absolutly correct. If the draft is right the stove should be able to operate as designed. At that point it is up to the operator it is no longer the stove or installs fault.

Of course we check the wood and check for defects with the stove. So have the installers in this case which is why they have moved on to dialing in the draft. How exactly would a combustion analysis tell you if part of the stove was broken? What about wet wood?

You keep insisting that flue gas analysis would be useful but you can offer no info on how it would be usefull or how those factors could be adjusted.

And if you really think that a partially blocked flue is going to draft fine you clearly have no clue how draft works. Which is astounding coming from a gas "expert".
 

Ryan723

Member
Oct 14, 2018
59
Layton, NJ
A single or even a few combustion analysis measurements during a burn likely will not tell you much about your system.

You would need regularly spaced or continuous sampling to really understand what is happening during a wood burn.

Here's why: the exact same load of wood will produce a variety of different gasses at different rates depending on HOW it is burned.

How hot is the burn? How quickly is the wood heated? Split size and surface area matters to this. Heck, the same exact load of wood could be STACKED differently in the firebox and have an entirely different burn profile!

Since you're then feeding the combustion process a variety of products at different rates throughout the burn, taking a look at the products of that combustion at any given time doesn't really tell you much.

This is very much the opposite of a gas or oil burner, where you feed the metered rate of identical combustion products throughout a burn cycle. That system reaches a steady state quickly where you can use combustion analysis to tune it in a way you cannot with wood.

Give this paper a read: https://www.fpl.fs.fed.us/documnts/fplmisc/rpt2136.pdf

"Rapid heating through the range of active pyrolysis tends to produce little charcoal, much tar, and highly flammable gases that are rich in hydrogen, carbon monoxide, and hydrocarbons; slow heating tends to produce much charcoal, little tar, and less flammable gases in which there is much water and carbon dioxide ( 79 ). In slow heating, decomposition proceeds in an orderly manner in which there is stepwise formation of increasingly stable molecules, richer in carbon and converging toward the hexagonal structure of graphitic carbon (9 , 3 9 , 8 7). In very rapid heating, macromolecules may be literally torn into volatile fragments with little possibility of orderly arrangement (7 9)."

Screenshot 2018-11-30 at 10.29.16 AM.png

I'd suggest that rather than a few measurements that are difficult and expensive to take, you'd be much better off measuring something easy—like temperature— and datalogging it throughout a burn if you really want to understand and troubleshoot a system.

Here's a load of wood in my BK from ~11AM yesterday to a reload ~8AM today. The jump around 8PM is where i bumped the t-stat for a little extra heat. Around midnight it transitions to more of a coaling stage. Before that combustion is variable and cycled by the BK t-stat air control. A measurement of combustion gasses anywhere in that first 12 hours could be all over the map—its constantly changing.
Screenshot 2018-11-30 at 10.36.47 AM.png
 
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Woodsplitter67

Minister of Fire
Jan 19, 2017
1,061
Woolwich nj
A single or even a few combustion analysis measurements during a burn likely will not tell you much about your system.

You would need regularly spaced or continuous sampling to really understand what is happening during a wood burn.

Here's why: the exact same load of wood will produce a variety of different gasses at different rates depending on HOW it is burned.

How hot is the burn? How quickly is the wood heated? Split size and surface area matters to this. Heck, the same exact load of wood could be STACKED differently in the firebox and have an entirely different burn profile!

Since you're then feeding the combustion process a variety of products at different rates throughout the burn, taking a look at the products of that combustion at any given time doesn't really tell you much.

This is very much the opposite of a gas or oil burner, where you feed the metered rate of identical combustion products throughout a burn cycle. That system reaches a steady state quickly where you can use combustion analysis to tune it in a way you cannot with wood.

Give this paper a read: https://www.fpl.fs.fed.us/documnts/fplmisc/rpt2136.pdf

"Rapid heating through the range of active pyrolysis tends to produce little charcoal, much tar, and highly flammable gases that are rich in hydrogen, carbon monoxide, and hydrocarbons; slow heating tends to produce much charcoal, little tar, and less flammable gases in which there is much water and carbon dioxide ( 79 ). In slow heating, decomposition proceeds in an orderly manner in which there is stepwise formation of increasingly stable molecules, richer in carbon and converging toward the hexagonal structure of graphitic carbon (9 , 3 9 , 8 7). In very rapid heating, macromolecules may be literally torn into volatile fragments with little possibility of orderly arrangement (7 9)."

View attachment 234418

I'd suggest that rather than a few measurements that are difficult and expensive to take, you'd be much better off measuring something easy—like temperature— and datalogging it throughout a burn if you really want to understand and troubleshoot a system.

Here's a load of wood in my BK from ~11AM yesterday to a reload ~8AM today. The jump around 8PM is where i bumped the t-stat for a little extra heat. Around midnight it transitions to more of a coaling stage. Before that combustion is variable and cycled by the BK t-stat air control. A measurement of combustion gasses anywhere in that first 12 hours could be all over the map—its constantly changing.
View attachment 234417
Yeah..... what he said.....
 

Woodsplitter67

Minister of Fire
Jan 19, 2017
1,061
Woolwich nj
Some tall asks for someone that runs scrap wood in an old smoke dragon that belches out 25x more pollutants. Travis has free tours of their factory in Mukilteo. You can see the highly instrumented testing they do there. It is extensive and not inexpensive.
I like this one.. wonder why he never replied to this
 

wooduser

Minister of Fire
Nov 12, 2018
680
seattle, wa
Cathy Lacenere <CLacenere@mybacharach.com>
Nov 30, 2018, 11:28 AM (15 hours ago)


to me


Hi Will,

Thank you for your inquiry.

I checked with our tech Support & Sr Sales Rep & they don’t have any additional information specific to wood stoves.

They suggested that you might want to pick an instrument with higher CO range.

Here is the comparison chart on our analyzers;

Combustion & Emissions Analyzers Archives - Bacharach, Inc.

The data sheets on the Insight Plus ( starts at $1350) & PCA400 (starts at $2700)reference wood for the fuels they support.

Another factor is are you doing residential, commercial or industrial us?

Please contact us with any questions or for additional information.

Best Regards,

Cathy Lacenere
 
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bholler

Chimney sweep
Staff member
Jan 14, 2014
18,617
central pa
Cathy Lacenere <CLacenere@mybacharach.com>
Nov 30, 2018, 11:28 AM (15 hours ago)


to me

Hi Will,

Thank you for your inquiry.

I checked with our tech Support & Sr Sales Rep & they don’t have any additional information specific to wood stoves.

They suggested that you might want to pick an instrument with higher CO range.

Here is the comparison chart on our analyzers;

Combustion & Emissions Analyzers Archives - Bacharach, Inc.

The data sheets on the Insight Plus ( starts at $1350) & PCA400 (starts at $2700)reference wood for the fuels they support.

Another factor is are you doing residential, commercial or industrial us?

Please contact us with any questions or for additional information.

Best Regards,
Cathy Lacenere
So no info on how that info would be applicable to a natural draft wood stove just help on what product to buy to give you those useless figures.
 
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wooduser

Minister of Fire
Nov 12, 2018
680
seattle, wa
So no info on how that info would be applicable to a natural draft wood stove just help on what product to buy to give you those useless figures.
That's true.


I had been hoping for something more directly helpful and applicable, but nothing there.


A carbon monoxide detector measuring levels up to 40,000 PPM (4% CO) might be interesting to use to measure poor combustion in flue gasses. Similarly, knowing the levels of oxygen in flue gasses ought to be a good indicator of the amount of excess air, too much or too little perhaps.

But I haven't been able to find authoritative references for these ideas and applying them to gravity vented wood stoves in the field.

I'll continue to do some looking around, though.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
18,617
central pa
That's true.


I had been hoping for something more directly helpful and applicable, but nothing there.


A carbon monoxide detector measuring levels up to 40,000 PPM (4% CO) might be interesting to use to measure poor combustion in flue gasses. Similarly, knowing the levels of oxygen in flue gasses ought to be a good indicator of the amount of excess air, too much or too little perhaps.

But I haven't been able to find authoritative references for these ideas and applying them to gravity vented wood stoves in the field.

I'll continue to do some looking around, though.
At what point in the burn would you take the measurement? And how would you adjust to correct for proper combustion?
 

lsucet

Minister of Fire
May 14, 2015
1,552
San Ysidro, New Mexico

Ludlow

Minister of Fire
Jun 4, 2018
1,082
PA
Are yearly emissions inspections required? Where are we gonna put the sticker?
 
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lsucet

Minister of Fire
May 14, 2015
1,552
San Ysidro, New Mexico
Are yearly emissions inspections required? Where are we gonna put the sticker?
Nohh, we can solved that with a rural address.:)
 

wooduser

Minister of Fire
Nov 12, 2018
680
seattle, wa
At what point in the burn would you take the measurement? And how would you adjust to correct for proper combustion?

I would look for Xpert training and advice on how to use combustion analysis with a natural draft wood stove. I've actually started doing that with posts on this thread and by soliciting advice from bacharach. But more can be done, I would suppose.

Absent Xpert training and advice on how to do that kind of combustion analysis, I'd take several reading and correlate the data with the apparent stage at which the fire is burning. Doing that on several different stoves might give enough information and experience to determine how and when such information could be used effectively. as an aid in solving the issues with problem combustion situations. (which could be such things as unsuitable wood, damaged stove, wrong operation, improper venting or other things.

But I'm not an Xpert with wood stoves, and I don't have the experience I suggest would be desirable to decide how combustion analysis might be useful. Perhaps it isn't. t it seems like it ought to be useful in solving some problem situations, and to give assurance that a problem has been accurately diagnosed. But I'm just guessing with that suggestion.

Just seems to me that more data is better than no data. And data such as stove temperature is found to be useful by our Xperts, and that's part of combustion analysis.


Anyhow, I'm a retiree. My time is my own to use, and investigating this is worthwhile to me. If it comes to nothing, that's fine too.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
18,617
central pa
I would look for Xpert training and advice on how to use combustion analysis with a natural draft wood stove. I've actually started doing that with posts on this thread and by soliciting advice from bacharach. But more can be done, I would suppose.

Absent Xpert training and advice on how to do that kind of combustion analysis, I'd take several reading and correlate the data with the apparent stage at which the fire is burning. Doing that on several different stoves might give enough information and experience to determine how and when such information could be used effectively. as an aid in solving the issues with problem combustion situations. (which could be such things as unsuitable wood, damaged stove, wrong operation, improper venting or other things.

But I'm not an Xpert with wood stoves, and I don't have the experience I suggest would be desirable to decide how combustion analysis might be useful. Perhaps it isn't. t it seems like it ought to be useful in solving some problem situations, and to give assurance that a problem has been accurately diagnosed. But I'm just guessing with that suggestion.

Just seems to me that more data is better than no data. And data such as stove temperature is found to be useful by our Xperts, and that's part of combustion analysis.


Anyhow, I'm a retiree. My time is my own to use, and investigating this is worthwhile to me. If it comes to nothing, that's fine too.
More data is better if and only if that data gives you useful info. All of the issues you say it could help diagnose are already really easy to diagnose with $100 or so worth of equipment.
 

Drewman

Member
Aug 10, 2015
80
Ohio
I was talking to Pacific Energy yesterday about controlling draft and he said that the EPA regulations has hand cuffed the manufacturers with the ability to control draft by reducing air intake.
They now have to resort to other methods to control draft which restrict chimney flow like a flue damper or restricter plate.

PE installed a 3.5” restricter plate under my chimney cap last week . Helped some, but I still have a high draft issue. They’re back to the drawing board trying to figure out how to slow down the draft on my FP30 zero clearance so I can burn full loads N/S without it going nuclear.


Sent from my iPhone using Tapatalk
How long is a fully loaded firebox lasting you and what species of seasoned wood are you burning?
 
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kennyp2339

Minister of Fire
Feb 16, 2014
4,386
07462
In my days as a gas appliance repairman for a utility, the utility installed conversion burners to replace oil burners. A repairman then went out with equipment less sophisticated than this to dial in the amount of gas input, combustion air, Oxygen and carbon monoxide to get efficient performance from the new burner.

Why shouldn't we expect the same in the wood stove industry?
Wouldn't it be hard to tune a woodstove when really all you have to actually tune it is air adjustments which is a variable in it self because all drafts are different (chimney is the engine that drives the stove) and cord wood variables such as species, split size, moisture content (uncontrollable for specific tuning)
I'd take your energy, thoughtfulness, and experience and go into stove design / development
 

wooduser

Minister of Fire
Nov 12, 2018
680
seattle, wa
The first thing a combustion analysis would tell you is whether or not there is a problem. If the draft, stack temperature, oxygen level, carbon monoxide and such are all at reasonable levels, you probably don;t have much to worry about.

If something is out of line such as a high carbon monoxide reading, then you want to go in and find out why. There is probably a defect in the gas input to the stove, burner adjustment,venting or something else causing the problem.

That way you aren't guessing and supposing. Frankly, if you aren't measuring carbon monoxide in the flue gasses, you don't know what's happening in the stove. You can't always tell if a gas burner is making CO by observing the flame.


That's a lot different than the post you quoted where I noted I was setting up conversion burners in oil fired furnaces where you could adjust the input from 30,000 BTU per hour to 300,000 BTU/hour, and with combustion air thatwould be way too much or way too little, producing huge amounts of carbon monoxide. In that situation, combustion analysis was essential to set up the conversion burner to operate properly with the particular furnace.

Oh, my! my background doesn't fit me for designing stoves at all! I was pretty good at maintaining and repairing them, though.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
18,617
central pa
The first thing a combustion analysis would tell you is whether or not there is a problem. If the draft, stack temperature, oxygen level, carbon monoxide and such are all at reasonable levels, you probably don;t have much to worry about.

If something is out of line such as a high carbon monoxide reading, then you want to go in and find out why. There is probably a defect in the gas input to the stove, burner adjustment,venting or something else causing the problem.

That way you aren't guessing and supposing. Frankly, if you aren't measuring carbon monoxide in the flue gasses, you don't know what's happening in the stove. You can't always tell if a gas burner is making CO by observing the flame.


That's a lot different than the post you quoted where I noted I was setting up conversion burners in oil fired furnaces where you could adjust the input from 30,000 BTU per hour to 300,000 BTU/hour, and with combustion air thatwould be way too much or way too little, producing huge amounts of carbon monoxide. In that situation, combustion analysis was essential to set up the conversion burner to operate properly with the particular furnace.

Oh, my! my background doesn't fit me for designing stoves at all! I was pretty good at maintaining and repairing them, though.
We are talking about wood stoves here not gas.
 

saydinli

Burning Hunk
Nov 6, 2016
233
Near Fergus Ontario
How long is a fully loaded firebox lasting you and what species of seasoned wood are you burning?
I am burning a variety really. A Lot of it is ash, some maple, a bit of oak. Not sure ehat some of it is.
If I fill it loaded E/W I can get 8 hours. Loaded N/S might only be about 6.

Im hoping once my draft control is better I can get 8-10 on a N/S load.


Sent from my iPhone using Tapatalk
 

georgepds

Minister of Fire
Nov 25, 2012
873
Re" Shucks, UI'm sure most people reading this board could characterize several different stages of wood combustion, from igniting kindling and initial warmup of a cold stove through the dying embers at the end of the combustion cycle."

My guess is you could quantify most of this by weighing the stove during the burn. The change in weight is proportional to the burn rate