Pellet Stove Tests

[F4jock]

But that's where your wrong. A Mt Vernon freestanding stove is not going to throw any more noticeable heat than an insert .

That isn't what I said. What I said was that a freestanding will radiate heat in more directions.

 

[John Ackerly]

Hey guys maybe a stupid question here but what does "cleanliness"mean exactly? How dirty the inside of the stove becomes or its exhaust?

Just the exhaust stream. And measured by carbon monoxide, as a proxy for particulate matter. Cleanliness inside stove was partly assessed through visibility of the glass - and maintanence of burn pot.

 

[Gabriella McConnel]

Hey guys maybe a stupid question here but what does "cleanliness"mean exactly? How dirty the inside of the stove becomes or its exhaust?

We measured the Carbon Monoxide concentration for the Cleanliness rating score.

Here is the link to that section: (broken link removed to http://www.forgreenheat.org/decathlon/clean.html)

Here is the link to the background on cleanliness: (broken link removed to http://www.forgreenheat.org/decathlon/cleanliness.html)

 

[F4jock]

Just the exhaust stream. And measured by carbon monoxide, as a proxy for particulate matter. Cleanliness inside stove was partly assessed through visibility of the glass - and maintanence of burn pot.

Carbon monoxide, a gas, is a proxy for particulates, a solid? Exhaust gas composition is indicative of combustion efficiency, not cleanliness unless you choose to define / equate gaseous emissions with cleanliness and ignore particulates.

 

[John Ackerly]

Carbon monoxide, a gas, is a proxy for particulates, a solid? Exhaust gas composition is indicative of combustion efficiency, not cleanliness unless you choose to define / equate gaseous emissions with cleanliness and ignore particulates.

Its bit more complicated in wood stove testing, where the tail end of the burn will have high CO and low PM. But for much of the burn, CO and PM will track each other. In a pellet stove, its easier, as its a steady state burn, so CO and PM act in unison, both being indicators of incomplete combustion. If you want to check out the science behind that, there are some footnotes in the report about CO and PM.

 

[F4jock]

So you contend that the correlation of CO2 to particulates in Guatemalan wood cooking stoves burning whatever-wood is a one-to-one correspondence with a pellet stove in the USA and therefore can be reliably used to predict their particulate emissions? I've been reading several combustion and emissions studies that call that relationship into question.

In short, although you can confidently state the stove-to-stove variance in CO2 emissions you are making quite a leap of logic to use this data to measure particulate "cleanliness."

I'm presently reading my fourth study, this one from Brookhaven Labs.

 

[F4jock]

I looked at them and as an engineer I have serious misgivings about the test conditions used and their correlation to pellet stoves.

I've read several studies and am presently wading through one from Brookhaven Labs.

 

[John Ackerly]

So you contend that the correlation of CO2 to particulates in Guatemalan wood cooking stoves burning whatever-wood is a one-to-one correspondence with a pellet stove in the USA and therefore can be reliably used to predict their particulate emissions? I've been reading several combustion and emissions studies that call that relationship into question.

In short, although you can confidently state the stove-to-stove variance in CO2 emissions you are making quite a leap of logic to use this data to measure particulate "cleanliness."

I'm no engineer, but our testing was developed with input from a bunch of Ph.D.s who have lots of experience testing biomass. Now that the EPA is requiring test labs to test for, and report efficiency and CO, we will slowly see a public database that can show he level of correlation between average CO and average PM. One thing about test lab data is that with PM, you just get to see how much PM is on the filter for however long you left it there - 1 hour, 3 hours, 8 hours. But new equipment that we have used a lot shows instantaneous PM and CO readings in digital format. So you can watch the degree that CO and PM track each other. I'm sure there is a Ph.D. these or two in there about how closely they track each other depending on the type of biomass combustion. So keep researching - and let us know what you find! Its always good to be skeptical and really understand how data is gathered and reported. There are a lot of issues in any test lab and tons of them with PM testings. We didn't have capacity to test PM here in Maryland, but feel confident with our CO results.

 

[Cory S]

I like turtles.

 

[F4jock]

I'm no engineer, but our testing was developed with input from a bunch of Ph.D.s who have lots of experience testing biomass. Now that the EPA is requiring test labs to test for, and report efficiency and CO, we will slowly see a public database that can show he level of correlation between average CO and average PM. One thing about test lab data is that with PM, you just get to see how much PM is on the filter for however long you left it there - 1 hour, 3 hours, 8 hours. But new equipment that we have used a lot shows instantaneous PM and CO readings in digital format. So you can watch the degree that CO and PM track each other. I'm sure there is a Ph.D. these or two in there about how closely they track each other depending on the type of biomass combustion. So keep researching - and let us know what you find! Its always good to be skeptical and really understand how data is gathered and reported. There are a lot of issues in any test lab and tons of them with PM testings. We didn't have capacity to test PM here in Maryland, but feel confident with our CO results.

OK then, since "fine" particulates, (PM 2.5) are apparently of most concern, please show me where your study quantifies them as a percentage of total particulates correlated with CO. As well, total particulates vary depending on the fuel source, BUT completeness of combustion as well as fuel directly affects gaseous emissions.

If you can't make direct measurements of PM you can only assume that your correlation is acurate and since the fuel source and combustion conditions vary greatly between what you are using as a baseline and the test conditions you promulgated, there is a large windows for error and it should be so stated in the results.

Essentially you can say that there is a likelihood that total particulate emissions tracked CO, but, as direct testing was not performed, you can only state that these results are speculative and, along with particle size distribution, which is also important, need to be independently quantified and verified by more testing at a later date.

 

[Wilbur Feral]

Yep Will. I paid nothing and that's about what it's worth.

Before you start demeaning people maybe you should review the scientific method of evaluating mechanical devices like for like and the proper presentation of data. Now I could get snarky like you and posit that while I was taking engineering courses you were apparently enrolled in the Liberal Arts equivalent of "How to insult people who disagree with you" . . . .

Actually, I just find your willingness to sling mud at forum members who contributed their time and effort toward a test that they hoped would help others to be a curious thing. You can debate methods - just show some respect for what they tried to do.

I'd engage you on the other stuff, but it's just not worth the effort. I can watch peacocks strut around in the neighbor's yard, without bothering others. It's sort of the same thing.

 

[LuvMyPellets]

What is a Forum Bully?
Bullying is about power and dominance. In online forums, bullies use words to intimidate, isolate, and degrade their victims.Bullies are in-love with themselves. They have little to no empathy, and are only interested in their own activities, and their own power.One of the best ways to deal with online bullies is to hit the delete button. If we cannot delete their comment in fact, then simply delete it from our consciousness and move on.

 

[Johnny_Fiv3]

While F4 is in fact, quite blunt, gruff, and a tad condescending at times, I feel he is asking valid questions. A guy like F4 is not welcomed everywhere, I get that. But man oh man, if I had him here, in the QA/QC department at my nuke plant, I would be able to KNOW a questioning attitude was being embraced and no one was "sneaking one by".

 

[tiger]

If we cannot delete their comment in fact, then simply delete it from our consciousness and move on.

Sadly, after considering it for about a year, following this topic I decided to visit my Preferences and add to my Ignore list, despite the fact that I'll likely miss out on some valuable knowledge.

Not you, LuvMyPellets.

 

[wildbill]

I like turtles too, and my insert, and my free standing stoves, that said its apples to orange's. we all know the diff as how heat radiates as one will and one needs the fan [ insert], that said it was a good article with a a lot of info to inform ppl as to the benefits of different stoves and the diff between the popular stoves available. Idk everyone runs there stoves different, is there any diff if one sifts his pellets to one who dumps in the bag with more fines than the brand with less fines. to many variables I think. heat is heat ...I lied I like dogs better. Lol., oh and my Accentra 52 , p68,

 

[Kennyz]

What about outsides air kits? Are you running these on all of your test stoves, you should be. This will greatly effect the efficiency and burn of a stove, especially when five stoves are running right next to each other.

 

[RMongeau]

Sadly, after considering it for about a year, following this topic I decided to visit my Preferences and add to my Ignore list, despite the fact that I'll likely miss out on some valuable knowledge.

Not you, LuvMyPellets.

I couldn't figure out who people were complaining about .......then I realized I already had this person on ignore. The only one.

 

[F4jock]

While F4 is in fact, quite blunt, gruff, and a tad condescending at times, I feel he is asking valid questions. A guy like F4 is not welcomed everywhere, I get that. But man oh man, if I had him here, in the QA/QC department at my nuke plant, I would be able to KNOW a questioning attitude was being embraced and no one was "sneaking one by".

I spent three years starting up PPL's Susquehanna SES 2 and then had to go over to Unit 1 to unscrew what some people who dealt fast and loose with data did to it so yeah Johnny, I know from both nukes and ignorance and their consequences and I have very little tolerance for the latter. In my business lives sometimes depend on getting the details right the first time. I like sleeping at night.

 

[smwilliamson]

That isn't what I said. What I said was that a freestanding will radiate heat in more directions.

I think you'd have to weigh the casting of each and realized that the thermal mass capacity is about the same

 

[F4jock]

But with the insert in fireplace the radiant surface exposed to the room is approximately 25 to 30% of a free standing and only points out and a bit out, ergo. . . . .

 

[bags]

The P Series free standing will and does produce much more radiant heat than any inserts. The entire unit is out in the open so there is much more steel and transmitting mass within that given room. Not saying inserts do not give some radiant but it would only be a much smaller percentage like F4 suggests in all reality.

My P68 gets very hot on the entire top, front, and both sides whereas if it was stuffed into a hearth much of that surface area would be absorbed inside the fire place warming the masonry and not as easily radiated into the room. This was a big factor for me here in my decisions on a new stove. I have a huge stone fire place I was tempted to put an insert into to replace the Lopi wood insert but since I have high vaulted ceilings and a lot of glass I needed all the extra I could get. I am confident that and insert would heat as well but one would never do the job the 68 does especially during the extended frigid cold spells.

 

[Harvey Schneider]

John, what I meant about the radiant heat is that a free-standing has more heated surfaces and can radiate 360. An insert radiates primarily unidirectionally. This should be really evident under low-fire conditions where the blower is off. No matter how you direct the heat from an insert the lack of radiant surface and the limited psitioning ability is going to gimp it somewhat compared to a free-standing of ostensibly the same BTU output.

I have two stoves, one is an insert. They both radiate pretty much unidirectionally. There is almost no heat comming off the back of my free standing stove because that is where the electronics and motors are located.
I would further question if radiation is a significant mode of heat transfer for a pellet stove. I don't believe temperatures are high enough for significant radiation. The primary means of heat extraction for a pellet stove is through the convection blower.
Just my opinions.

 

[F4jock]

I have two stoves, one is an insert. They both radiate pretty much unidirectionally. There is almost no heat comming off the back of my free standing stove because that is where the electronics and motors are located.
I would further question if radiation is a significant mode of heat transfer for a pellet stove. I don't believe temperatures are high enough for significant radiation. The primary means of heat extraction for a pellet stove is through the convection blower.
Just my opinions.

Not the top or the top or the sides?

 

[alternativeheat]

I have two stoves, one is an insert. They both radiate pretty much unidirectionally. There is almost no heat comming off the back of my free standing stove because that is where the electronics and motors are located.
I would further question if radiation is a significant mode of heat transfer for a pellet stove. I don't believe temperatures are high enough for significant radiation. The primary means of heat extraction for a pellet stove is through the convection blower.
Just my opinions.

Harvey, I own a P61 and on a cold winters night with it cranking at a moderate burn, sometimes high burn, you back away from it. We have chairs on each side of the stove just outside the tolerance distance and you find yourself leaning away from the stove sides. The paint on the sides of my stove is starting to have a center spot of discolor just like my radiant only all steel coal stove used to do ( though it was more drastic and needed paint periodically). So the P series stoves radiate heat as well as blow by convection.. it's actually one reason I bought this unit over a P52i, I wanted that radiant heat and I get it. Let me put it this way, you aren't putting your hand on it, ok, and you won't find a cat sleeping on top of it LOL, like you might see in some peoples photos.. Primary heat by convection fan , yes that is true but cast stoves and certainly inserts do not radiate like all steel P series Harmans do. I've been to many shops running stoves and you can put your hands right on most of them. They probably are 80-90% convection via blower output.

 

[John Ackerly]

What about outsides air kits? Are you running these on all of your test stoves, you should be. This will greatly effect the efficiency and burn of a stove, especially when five stoves are running right next to each other.

We were running the stoves in a screened in porch. So they all had outdoor air, in a way. Sometimes that air was really warm, and sometimes it was cool. But it was never cold, as we did the testing in Maryland in September.