Combustion Analyzer

[wooduser]

https://www.instrumart.com/products/45158/bacharach-pca400-portable-combustion-analyzer#!description


Here's an example of a modern combustion analyzer for identifying what's going on in fuel burning appliances, wood stoves included.


In reading through reviews on equipment, people seeking help with stoves that are working poorly and such, I'm struck by how little actual information people have when they try to identify and remedy problems.

A combustion analyzer like this is the answer to finding out what is going on in many cases:

Measuring stack temperature, draft, O2 level, carbon monoxide and other such data should allow a much more authoritative analysis of problems and lead to much more reliable repairs and adjustments.

While pricey at $2000, what price can you put on a homeowner sold a new stove who is bitterly disappointed by the stove's performance, and can't get the dealer/installer to fix it, because they don't know what's going on?

I suggest that if dealers and installers had at least one of these to use when going out on such problem calls, they would pay for themselves by reducing repeat service calls, returned equipment and unhappy customers.

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?

 

[bholler]

https://www.instrumart.com/products/45158/bacharach-pca400-portable-combustion-analyzer#!description


Here's an example of a modern combustion analyzer for identifying what's going on in fuel burning appliances, wood stoves included.


In reading through reviews on equipment, people seeking help with stoves that are working poorly and such, I'm struck by how little actual information people have when they try to identify and remedy problems.

A combustion analyzer like this is the answer to finding out what is going on in many cases:

Measuring stack temperature, draft, O2 level, carbon monoxide and other such data should allow a much more authoritative analysis of problems and lead to much more reliable repairs and adjustments.

While pricey at $2000, what price can you put on a homeowner sold a new stove who is bitterly disappointed by the stove's performance, and can't get the dealer/installer to fix it, because they don't know what's going on?

I suggest that if dealers and installers had at least one of these to use when going out on such problem calls, they would pay for themselves by reducing repeat service calls, returned equipment and unhappy customers.

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?

And what would that info tell us a wood stove techs? How would we adjust them?

 

[bholler]

Most of us who work on stoves know what combustion analyzers are but i really dont see how that info would help me. You cant fine tune things with a wood stove like you can with gas appliances.

 

[wooduser]

Most of us who work on stoves know what combustion analyzers are but i really dont see how that info would help me. You cant fine tune things with a wood stove like you can with gas appliances.

I agree, it's nice to have a combustion system that just sits there and BURNS!

Still. I found this comment on a thread posted today:

<<I sent the pic directly to Hearthstone, they kindly responded quickly, and they tell me, things have changed on the latest Heritage, and my baffle is fine, there is no longer the front support as on the older ones - they believe it's a draft issue, and I'm going to extend my pipe higher, and see if this helps. I remeasured my pipe today, and I was off by 2 feet - I'm about 14 feet from top of stove to top of chimney.

THEY BELIEVE IT'S A DRAFT ISSUE! How convenient. They can disclaim responsibility based on their GUESS.

If someone was out there MEASURING the draft, stack temperature, O2, CO and such don't you think that people could quit guessing and start actually solving problems for customers?

 

[bholler]

I agree, it's nice to have a combustion system that just sits there and BURNS!


Still. I found this comment on a thread posted today:

<<I sent the pic directly to Hearthstone, they kindly responded quickly, and they tell me, things have changed on the latest Heritage, and my baffle is fine, there is no longer the front support as on the older ones - they believe it's a draft issue, and I'm going to extend my pipe higher, and see if this helps. I remeasured my pipe today, and I was off by 2 feet - I'm about 14 feet from top of stove to top of chimney.


THEY BELIEVE IT'S A DRAFT ISSUE! How convenient. They can disclaim responsibility based on their GUESS.

If someone was out there MEASURING the draft, stack temperature, O2, CO and such don't you think that people could quit guessing and start actually solving problems for customers?

Well yes we do measure draft. But its kind of hard for them to do that over the phone. And we dont need a $2000 analyzer to do it. I am asking what you think knowing the o2 and co levels would tell us?

 

[wooduser]

The O2 level tells you if you have an excess of air going through the stove, probably too fast to give upm heat effectively.

Since carbon monoxide is a major component of wood gas, having too much raw co in the stack gas indicates perhaps not enough combustion air to burn the gases or temperatures not high enough to burn them properly.

Of course, it's a balance between these different factors, and with a wood stove you need experience deciding when to take measurements and how to interpret them, I'm sure.

<<Well yes we do measure draft. Glad to hear that, since I haven't heard any reference to actually doing that until your comment. I've seen LOTS of reference to people guessing that the draft wasn't high enough. In one case I saw the dealer said the draft wasn't high enough and the customer later figured out the draft was TOO high and the cause of his problem!

I was reading an article on how wood stove testing is done, and measuring the flue gasses is an important part of the testing. I suggest that it would be useful for techs in the field to be able to do that as well, and be skilled in how to interpret the data.

Shucks, I ought to buy a small draft gauge and stick it in another hole in my wood stove stove pipe to give me something new to look at in addition to my stack thermometer! Might be kind of entertaining.

 

[bholler]

The O2 level tells you if you have an excess of air going through the stove, probably too fast to give upm heat effectively.

Since carbon monoxide is a major component of wood gas, having too much raw co in the stack gas indicates perhaps not enough combustion air to burn the gases or temperatures not high enough to burn them properly.

Of course, it's a balance between these different factors, and with a wood stove you need experience deciding when to take measurements and how to interpret them, I'm sure.

<<Well yes we do measure draft. Glad to hear that, since I haven't heard any reference to actually doing that until your comment. I've seen LOTS of reference to people guessing that the draft wasn't high enough. In one case I saw the dealer said the draft wasn't high enough and the customer later figured out the draft was TOO high and the cause of his problem!


Shucks, I ought to buy a small draft gauge and stick it in another hole in my wood stove stove pipe to give me something new to look at in addition to my stack thermometer! Might be kind of entertaining.

Yes what you say is true to much o2 or co can give you info. But it could also be misleading depending upon the point in the burn you measure at. And i can tell all of those things with a temp guage and a draft gauge. When we are onsite it is not hard to diagnose the problem. And an expensive peice of equipment is not needed.

 

[begreen]

Why shouldn't we expect the same in the wood stove industry?

Because wood stoves don't have adjustments to "dial in" ideal O2 and CO settings. To do so could invalidate the EPA testing and possibly the UL certification. Better training of installers and salespeople would help, but that isn't going to protect the consumer from their own mistakes like burning poorly seasoned wood or not maintaining the stove.

 

[begreen]

THEY BELIEVE IT'S A DRAFT ISSUE! How convenient. They can disclaim responsibility based on their GUESS.

If someone was out there MEASURING the draft, stack temperature, O2, CO and such don't you think that people could quit guessing and start actually solving problems for customers?

And when the customer is >100 miles away? Just imagine the cost of the service call for round trip travel time alone.

 

[wooduser]

http://www.dwyer-inst.com/Product/TestEquipment/Manometer/AirVelocity/Model460

Here's an example of a manometer suitable for measuring furnace/stove draft, for those wondering.

Glad to hear that you guys have the instruments you need to solve the problems you deal with.

I was getting frustrated by reading of all the guessing and supposing going on, and no measurements. And still people unhappy with their new equipment.

And I'm sure it's frustrating when customers play a vital role in stove performance, but lack the skills and knowledge to be able to perform their function effectively.

I'd suppose that in most cases, complaints you deal with aren't the result of defective new equipment. Instead I'd suppose (guess) that poor installation, poor operation of equipment and poor fuel are the major problems.

I still have a vivid memory of being called out by an installer who had put in a new gas furnace that WOULDN'T WORK! He was pretty POd about it when I got there ----his time being wasted. A few minutes of troubleshooting disclosed that he had cut through a wire which was the reason the furnace wouldn't work. One look at something he couldn't ignore changed his attitude completely!

I would suppose that it's harder for a customer or installer to argue with hard facts that have been measured than simply with opinions. Most of the people posting about their new equipment that doesn't work right seem to get opinions rather than measurements about the problems.

 

[bholler]

http://www.dwyer-inst.com/Product/TestEquipment/Manometer/AirVelocity/Model460


Here's an example of a manometer suitable for measuring furnace/stove draft, for those wondering.

Glad to hear that you guys have the instruments you need to solve the problems you deal with.

I was getting frustrated by reading of all the guessing and supposing going on, and no measurements. And still people unhappy with their new equipment.

And I'm sure it's frustrating when customers play a vital role in stove performance, but lack the skills and knowledge to be able to perform their function effectively.

I'd suppose that in most cases, complaints you deal with aren't the result of defective new equipment. Instead I'd suppose (guess) that poor installation, poor operation of equipment and poor fuel are the major problems.

I still have a vivid memory of being called out by an installer who had put in a new gas furnace that WOULDN'T WORK! He was pretty POd about it when I got there ----his time being wasted. A few minutes of troubleshooting disclosed that he had cut through a wire which was the reason the furnace wouldn't work. One look at something he couldn't ignore changed his attitude completely!

I would suppose that it's harder for a customer or installer to argue with hard facts that have been measured than simply with opinions. Most of the people posting about their new equipment that doesn't work right seem to get opinions rather than measurements about the problems.

You have to realize we are dealing with problems here without the benifit of being on site. Diagnosing problems in this way is very different

 

[wooduser]

And when the customer is >100 miles away? Just imagine the cost of the service call for round trip travel time alone.

Not too far to go to sell the equipment though, and then to install it?

Then again, the customer may save you going out again, by leaving the stove you sold him on your loading dock with a demand for his money to be returned.

I was a self employed repairman for 13 years, I know the frustration of making repeated service calls. But that mainly places a premium on doing the job right the first time, in my experience. (learned the hard way) One thing I learned was not to do repairs on equipment a hundred miles away! Or even fifty. Thirty at the outside. Twenty MUCH better, as a max.

During the summer, I'd take my boat out cruising in the wonderful waters of Puget Sound, the San Juan Islands and British Columbia. When people called me for repairs on my cell phone, I might have my feet up on the stern of the boat, I could schedule repair work for when I was going to be back in town ----didn't let work disturb my vacation!

And in British Columbian waters, there were lots of small logging and construction sites, fishing camps and such, all of which had loads of propane equipment, usually badly in need or service and maintenance. And completely isolated except by sea or float plane.

I used to daydream of going from camp to camp, tieing my boat up at the dock and soliciting repair and maintenance work that surely was needed and VERY hard to come by service. I figured if I was LUCKY, parts would be required and need to be special ordered, taking several days to be flown in on the next plane or whatever. In the meantime, I could stay tied up at the dock, and being fed at the crew dining hall. Perhaps fishing for salmon or buying sea food from fisherman stopping by. Now THAT would have been NICE!

 

[bholler]

Not too far to go to sell the equipment though, and then to install it?

Then again, the customer may save you going out again, by leaving the stove you sold him on your loading dock with a demand for his money to be returned.

I was a self employed repairman for 13 years, I know the frustration of making repeated service calls. But that mainly places a premium on doing the job right the first time, in my experience. (learned the hard way) One thing I learned was not to do repairs on equipment a hundred miles away! Or even fifty. Thirty at the outside. Twenty MUCH better, as a max.

During the summer, I'd take my boat out cruising in the wonderful waters of Puget Sound, the San Juan Islands and British Columbia. When people called me for repairs on my cell phone, I might have my feet up on the stern of the boat, I could schedule repair work for when I was going to be back in town ----didn't let work disturb my vacation!

And in British Columbian waters, there were lots of small logging and construction sites, fishing camps and such, all of which had loads of propane equipment, usually badly in need or service and maintenance. And completely isolated except by sea or float plane.

I used to daydream of going from camp to camp, tieing my boat up at the dock and soliciting repair and maintenance work that surely was needed and VERY hard to come by service. I figured if I was LUCKY, parts would be required and need to be special ordered, taking several days to be flown in on the next plane or whatever. In the meantime, I could stay tied up at the dock, and being fed at the crew dining hall. Perhaps fishing for salmon or buying sea food from fisherman stopping by. Now THAT would have been NICE!

The problem with your reasoning is in that case the customer is dealing with hearthsone directly. Hearthstone didnt install the stove. So they are working kind of blind

 

[Rearscreen]

I have a Testo analyzer that after rebate cost me 450 bucks. However, with a oil burner, it's pretty much constant, meaning the gasses and draft remain constant after the settings are dialed in to reach max efficiency. The draft on an oil burner also has a barometric draft that comes into play. What's interesting is, even before you use this instrument, you need to use a separate smoke test tool. This is basically a syringe that sucks the exiting gasses through a white paper like material. Not until it's almost still white do you do the analysis. I just can't imagine any of this working on a wood stove with accuracy with all of the variables.

 

[peakbagger]

I do boiler MACT tuning of large industral biomass boilers on occasion. They usually have Continuous Monitoring Systems (CEMS) which read out CO and O2 along with NOX. With an industrial boiler the fuel is wood chips thrown on a pinhole grate. Heated primary air is pumped under the grate and then there are a bunch of air ports aimed at and above the grate. There are also overfire air ports located up the shaft of the furnace. The trick with an industrial boiler is to get it burning hot but not too hot and length the flame front out so NOX generation due to too high temperatures. Since NOX isnt regulated with small boilers, the trick is to get a fast hot flame and have enough heat transfer area to grab the heat. My job on the big boilers is mostly to adjust the total air flow to reduce the excess O2 down and then shift the air between the undergrate, grate and overfire air to minimize CO while keeping NOx in check. The boilers I usually tune have Selective Catalysts for NOx reduction so I adjust it to burn hot to drop CO while staying on the edge of NOx. Its definitely a Rubik's cube.

On rare occasions we do use a couple of Testo's and on one occasion we have used three to look at the cross sectional operation of the boiler. What can happen with a large boiler is air can sneak up the sides of the furnace and keep the CO from burning. Unless there is a catalyst, the temperature has to be around 1200 degrees F for CO to burn and frequently too much air can be put in the wrong spot and then the CO goes sky high. By looking at the gases at different areas of the boiler outlet we can usually get a good idea where to focus on. We also on occasion use water cooled probes to extract gases from inside the furnace. This is not real easy to do but the data can be real valuable. The problem with most gas analyzers is they are extractive type units and the sensors can get fouled quick. We usually run the gases through bubble jars to cool the gases and keep the crap out. The sensors can get poisoned if exposed to too much CO so we have to be careful as its easy to spike CO in boiler.

I am switching employers and never did get a chance to play with one on my own boiler. I do have a secondary air port I could play with.

 

[wooduser]

I have a Testo analyzer that after rebate cost me 450 bucks. However, with a oil burner, it's pretty much constant, meaning the gasses and draft remain constant after the settings are dialed in to reach max efficiency. The draft on an oil burner also has a barometric draft that comes into play. What's interesting is, even before you use this instrument, you need to use a separate smoke test tool. This is basically a syringe that sucks the exiting gasses through a white paper like material. Not until it's almost still white do you do the analysis. I just can't imagine any of this working on a wood stove with accuracy with all of the variables.

It takes a while and some practice to get good use out of most instruments. So you've never used to combustion analyzer to try to figure out what's going on in a troublesome wood stove system?

There are certainly plenty of variabilities in wood combustion.

A Dutch government report I read on line analyzed wood stove combustion with several different add on systems to see if add ons such as electric precipitators or several others could be effective in reducing wood stove emissions. They did that on what they deemed existing and typical wood stove and wood boiler installations. Combustion gas analysis, including measuring particulates, were important parts of the study.

They identified four stages of wood combustion, and analyzed what was going on at each stage.

SOME tech has got to be using a combustion analyzer as part of their job. I see that most combustion analyzers are set up to analyze wood combustion gasses ---that suggests that somebody out there is using them.

Perhaps I'll be able to find one of those guys one day and find out how they use that test equipment.

 

[bholler]

It takes a while and some practice to get good use out of most instruments. So you've never used to combustion analyzer to try to figure out what's going on in a troublesome wood stove system?

There are certainly plenty of variabilities in wood combustion.

A Dutch government report I read on line analyzed wood stove combustion with several different add on systems to see if add ons such as electric precipitators or several others could be effective in reducing wood stove emissions. They did that on what they deemed existing and typical wood stove and wood boiler installations. Combustion gas analysis, including measuring particulates, were important parts of the study.

They identified four stages of wood combustion, and analyzed what was going on at each stage.

SOME tech has got to be using a combustion analyzer as part of their job. I see that most combustion analyzers are set up to analyze wood combustion gasses ---that suggests that somebody out there is using them.

Perhaps I'll be able to find one of those guys one day and find out how they use that test equipment.

Yes as i have said every other time you mentioned it they are used in design and testing of woodstoves. But by the time those stoves reach the market there is nothing for us to do with it. Yes with a forced combustion system or gasifiers it would be a benifit. But not on a standard natural draft woodstove.

So again can you tell us what benifit you think those numbers would tell us wotking on regular woodstoves that we couldnt figure out with much simpler and cheaper equipment.

 

[begreen]

Not too far to go to sell the equipment though, and then to install it?

Reread that thread. The stove was shipped to the customer and customer installed.

 

[begreen]

It takes a while and some practice to get good use out of most instruments. So you've never used to combustion analyzer to try to figure out what's going on in a troublesome wood stove system?

Perhaps I'll be able to find one of those guys one day and find out how they use that test equipment.

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.

 

[Adabiviak]

Not necessarily along the dimensions of these organic oxide counts, but more "how much soot/smoke/particulate matter is coming out of my stack" is a measurement I've been sporadically considering how to measure: specifically a simple (for certain values of easy), real-time monitor of my stove exhaust.

What I would like to track with this is information is first: my woodburning technique (am I pulling the intake too low, 'wasting' it at too high, minimizing my startup inefficiency, that sort of thing), and second: the nuances of different woods (this species burns super clean no matter what, where this other species throws up more soot unless I really get the box going, that sort of thing).

This tool seems like a good start: simple, but out of my price range for a fleeting interest like this. I could probably chart these over time to get baseline information and see how it changes as I adjust my variables, but that price.

 

[wooduser]

So again can you tell us what benifit you think those numbers would tell us wotking on regular woodstoves that we couldn't figure out with much simpler and cheaper equipment.

Well, I really don't know. Those numbers were essential in setting up gas conversion burners, which needed to operate safely, and without being monitored in the homes of customers. When conversion burners were improperly adjusted, or became improperly adjusted, they produced a lot of carbon monoxide and soot, and if the chimney became plugged they could and did kill people.

I don't have experience with wood stoves other than my own, and solving the issues people have with new wood stoves isn't my responsibility. Perhaps you can do that with the instruments you have.

I really don't know how you solve those problems, I merely see lots of people with new equipment that perhaps isn;t working right because it wasn't installed properly, they aren't using it properly or because they are using poor quality fuel. I'd like to see them get the help they need to have their equipment working properly.

What I do see is complaints that they have had installers and dealers inspect their equipment and tell them it's working FINE, but they aren't convinced. Perhaps they would be more likely to be convinced if a technical analysis of their stove was made and the technician walked them through their analysis and explained WHY the stove was working properly, or alternatively what needed to be done to make it work properly.

You guys may be doing that 100%. It may be some other poor dumb customer who is not getting the help he needs.

And frankly, I'd like to better understand how my stove operates. The only instrument I have available to me is my thermometer stuck in the vent pipe, which is better than nothing. (actually, I have a good quality digital CO detector which I ought to try in the stack as well, I'll have to see what reads I get with that.) I might buy myself a draft manometer to join the thermometer and see what I can see with that. Understanding how varying amounts of draft affect the operation of the stove and the nature of the flame and heat produced would be an additional step forward in understanding how to properly adjust and operate my wood stove.


<<Yes as i have said every other time you mentioned it they are used in design and testing of woodstoves. But by the time those stoves reach the market there is nothing for us to do with it. Yes with a forced combustion system or gasifiers it would be a benifit. But not on a standard natural draft woodstove.


Oh, c'mon. The wood STOVE is a given. But how it was installed is not. How it is being operated by the user is not. And the nature of the fuel being used, such as the moisture content is not. All those are FAR more variable than with a gas or oil furnace.

But the same types of measurements are key to having a wood stove system that works effectively and reliably. I'm sure you can identify weaknesses in that system, whether it's a defect in the stove, installation, operation by the customer or defective fuel. I would suppose doing that is the primary job of a wood stove technician. You may be able to do that with limited instruments, and if so, fine.

As a non tech, I'm trying to understand my stove without the experience you guys have, I really don't know what instruments you guys carry and use. More instruments would be a help to me in understanding the operation of my stove.

 

[wooduser]

Reread that thread. The stove was shipped to the customer and customer installed.

Shucks man, you were the one who protested that the customer was too far away to be provided service!

<<And when the customer is >100 miles away? Just imagine the cost of the service call for round trip travel time alone.


I'm really not interested in picking a fight with you guys y'know. I'm just interested in the operation of my own stove, and why so many other people seem to have a lot of trouble making their new stoves work properly. You guys may be doing a bang up job with EVERY stove user you see, and not be able to affect those facts of life.

Give me a little time to unlimber my digital CO meter. It pegs out at 2000 ppm CO, I'll be interested to see what I find in my stack. during various parts of the wood combustion cycle,. Any predictions?

 

[wooduser]

http://www.tsi.com/uploadedFiles/_Site_Root/Products/Literature/Handbooks/CA-basic-2980175.pdf


Here's an article on why and how to do combustion analysis, using some of the variables I've been discussing and more.

On page nineteen, the specifications for wood combustion and analysis are listed right along with those for oil, gas coal and other fuels.


For some reason, the authors don;t seem to think it's pointless to consider such issues.

 

[wooduser]

https://inspectapedia.com/heat/Oil_Burner_Smoke_Test.php


Testing of sooting in oil burner combustion gasses is common, and the norm has been to pump combustion gasses through a piece of filter paper and evaluate how much smoke or soot is present. I wouldn't be surprised if something similar couldn;t be done with wood stove stack gasses,

The studies I have been reading find a wide variety of sizes of particulates in wood smoke, from pretty large to very small. Some condense out of a gaseous state into particulates. Sounds like you interest in understanding the operation of your stove is similar to my own.

 

[Ludlow]

One fact to consider: The fuel in a gas, LP, or oil furnace is consistent. Supply, burn rate, Air mix all consistent. How can you analyze all the variables that a stove experiences in a burn cycle? A modern furnace's burn characteristics are not influenced by atmospheric effects on draft. Wood stove performance is a slave to it. You could run an analyzer on a wood stove and five minutes later it is meaningless. Not to mention the fuel will vary from one split to the next.