Pellet Musings

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
  • Hope everyone has a wonderful and warm Thanksgiving!
  • Super Cedar firestarters 30% discount Use code Hearth2024 Click here

minux

Member
Nov 30, 2018
146
Baltimore, MD
I am a Computer Scientist by education and an engineer by trade, so I wanted to share some direct experiences in hopes of increasing people's comfort in this cold season.

The background is I have an undersized pellet stove that is the primary source of heat for my 3,400 square foot home. I am working on adding another stove to the main level.

Stove is in the basement and runs 24/7 in Room Temp mode. 78 degrees brings the upstairs thermostat to 71 degrees. Perfect.

Some observations to share:

- Hard versus Soft Wood Pellets: Soft wood pellets do not burn as hot or clean as hard wood pellets in my Harman Accentra 52i. With soft woods, I had to empty and clean every week. When I cranked the burn rate, soft woods were obliterated in my stove. When I crank with hardwoods, a reasonable fill time is achieved. With hard woods, I can go two weeks without emptying the ash pan.

- Fan Speed and Temperature: Higher fan speeds do not equate to higher temperatures in my upstairs. When the fan was set to high in Room Temp mode, my upstairs never got above 70. Now that the fan is set to low, I get 71 in the upstairs.Plus, the basement is usable now without the stove sounding like a Cessna.

- Forced Air Fan and Temperature: When I circulated the air 30mins every hour, I did not have dramatic temperature increases. When I turned the fan off, the temperature reached 71. The culprit are ducts, which are an abysmal for heating/cooling with forced air. Doing a real calculation on energy loss, the results are staggering. Obviously, comfort and a reduced electricity bill were achieved.

- Insert Hoppers: Are greatly undersized and no upgrades are available for insert stoves from Harman or the secondary market. Keep this in consideration when purchasing and if you want to go the pellet stove router, free standing should be the first consideration. Fireplaces in general (i.e., when you need an insert) are really only good for aesthetics and should not be utilized as a primary source of heat, regardless of the insert type.If you must have a fireplace, forget a masonry fireplace and go with a vent-less propane fireplace, which yields more heat and will be less headache.

- High Efficiency Mini-splits: Make purchasing a pellet stove a hard sell, especially a top of the line stove, like a Harman. I would never buy an insert pellet stove.

- Stove Location & Type: The Harman I own came with the house. If I was buying a stove, I would go with a freestanding and install on the main level.

- Pellet Storage: Regardless of the liners, tarps, wraps, etc., never store pellets exposed to the elements.

I read a lot on these forums and used other’s experiences to dictate how I first approached the pellet stove. After much use, I think the X factor in all these discussions is home characteristics. I have a split foyer with a 140 sq ft exterior stairwell that connects the two levels. House is well insulated, except for one exterior door.
 
Last edited:
I suspect you had some poor quality "softies",others will probably chime in,I will leave you some reading material.As far as storing outside,a lot depends on where you live,and average humidity.If they are in a place where water will not pool underneath,concrete or stone pad,etc,and you tarp them,they will be good for a very long time. http://firewoodresource.com/wood-pellets/hardwood-vs-softwood-pellets/ http://www.woodpellets.com/heating-fuels/hardwood-softwood.aspx https://www.woodpellets.com/blog/2014/07/11/how-to-store-wood-pellets-inside-and-outside/
 
  • Like
Reactions: FirepotPete
Fan Speed and Temperature: Higher fan speeds do not equate to higher temperatures in my upstairs. When the fan was set to high in Room Temp mode, my upstairs never got above 70. Now that the fan is set to low, I get 71 in the upstairs.Plus, the basement is usable now without the stove sounding like a Cessna.

First saying your stove is undersized for your house is an understatement. These stoves are nothing more than a space heater and should not be expected to heat multilevel homes. It is hard enough to move heat around on a single level.

Fan Speed. While I can see why the results you are seeing are possible depending on the heat range, outside temp, wind speed and insulation. In general that is not a true statement if the stove is properly set up for the amount of fuel being used and the amount of exhaust that is being expelled. On low heat settings it would be more likely that you would see what you are seeing, just not enough heat to run the room fan on high. But for most of us that live in extreme cold areas and have dialed in our stoves over the years it is usually most efficient to run that fan on high and strip as much heat from the exhaust as possible.

It can take a couple of seasons to get a stove running properly, the most efficient. A lot of notes and note paper, hours taking temp measurements and tinkering. These for the most part are not plug and play no matter how much the stove costs.

Keep observing and good luck with the second stove, it should make a big difference but you are still heating a pretty big place and like I said before, it is hard to move heat throughout a house with these stoves.
 
  • Like
Reactions: Mt Bob
I am a Computer Scientist by education and an engineer by trade, so I wanted to share some direct experiences in hopes of increasing people's comfort in this cold season.

The background is I have an undersized pellet stove that is the primary source of heat for my 3,400 square foot home. I am working on adding another stove to the main level.

Stove is in the basement and runs 24/7 in Room Temp mode. 78 degrees brings the upstairs thermostat to 71 degrees. Perfect.

Some observations to share:

- Hard versus Soft Wood Pellets: Soft wood pellets do not burn as hot or clean as hard wood pellets in my Harman Accentra 52i. With soft woods, I had to empty and clean every week. When I cranked the burn rate, soft woods were obliterated in my stove. When I crank with hardwoods, a reasonable fill time is achieved. With hard woods, I can go two weeks without emptying the ash pan.

- Fan Speed and Temperature: Higher fan speeds do not equate to higher temperatures in my upstairs. When the fan was set to high in Room Temp mode, my upstairs never got above 70. Now that the fan is set to low, I get 71 in the upstairs.Plus, the basement is usable now without the stove sounding like a Cessna.

- Forced Air Fan and Temperature: When I circulated the air 30mins every hour, I did not have dramatic temperature increases. When I turned the fan off, the temperature reached 71. The culprit are ducts, which are an abysmal for heating/cooling with forced air. Doing a real calculation on energy loss, the results are staggering. Obviously, comfort and a reduced electricity bill were achieved.

- Insert Hoppers: Are greatly undersized and no upgrades are available for insert stoves from Harman or the secondary market. Keep this in consideration when purchasing and if you want to go the pellet stove router, free standing should be the first consideration. Fireplaces in general (i.e., when you need an insert) are really only good for aesthetics and should not be utilized as a primary source of heat, regardless of the insert type.If you must have a fireplace, forget a masonry fireplace and go with a vent-less propane fireplace, which yields more heat and will be less headache.

- High Efficiency Mini-splits: Make purchasing a pellet stove a hard sell, especially a top of the line stove, like a Harman. I would never buy an insert pellet stove.

- Stove Location & Type: The Harman I own came with the house. If I was buying a stove, I would go with a freestanding and install on the main level.

- Pellet Storage: Regardless of the liners, tarps, wraps, etc., never store pellets exposed to the elements.

I read a lot on these forums and used other’s experiences to dictate how I first approached the pellet stove. After much use, I think the X factor in all these discussions is home characteristics. I have a split foyer with a 140 sq ft exterior stairwell that connects the two levels. House is well insulated, except for one exterior door.

I know you think you are trying to offer good advice, you’re not.

Just to classify soft vs hard pellets is a giant mistake. There are many different grades of each!

Moving air from a basement to upstairs is a crapshoot at best, it is not what your stove was designed for.

A Harman P35i holds over 50lbs of pellets with the larger hopper, that is plenty!

I don’t mean to pick apart everything you have said and I won’t. Even though I could for 99% of what you are saying.

I will just say that the same stove may perform differently from one address to another, never mind just the same model.
 
I know you think you are trying to offer good advice, you’re not.

OK...

Just to classify soft vs hard pellets is a giant mistake. There are many different grades of each!

Multiple varieties tested.

Moving air from a basement to upstairs is a crapshoot at best, it is not what your stove was designed for.

What *** exactly *** were out stoves designed for? Our stoves were designed to produce hot air. My stove is moving hot air and heating the entire house with the information I provided.

A Harman P35i holds over 50lbs of pellets with the larger hopper, that is plenty!

You would rather spend your time on earth repeatably filling up a hopper than doing anything else?

I don’t mean to pick apart everything you have said and I won’t. Even though I could for 99% of what you are saying.

OK... A lot of misinformation on here that is flat out incorrect. My musings are here to help.
 
OK...



Multiple varieties tested.



What *** exactly *** were out stoves designed for? Our stoves were designed to produce hot air. My stove is moving hot air and heating the entire house with the information I provided.



You would rather spend your time on earth repeatably filling up a hopper than doing anything else?



OK... A lot of misinformation on here that is flat out incorrect. My musings are here to help.

Many unanswered questions that you left for the members here.

How long have you lived there and used that stove?

Was the stove itself in the house when you moved in?

Who installed it? What are the actual dimensions of the exhaust and fresh air intake (if you have a FAI) lengths of piping, horizontal and vertical?

When you changed the room fan setting how long did you wait to see a change in the temp of the other rooms?

More info is always better for us that read this and will try and help. You say in the OP at the top of this thread that you are putting out info for people to learn what you have learned, then you have to also realize most of us are not trying to heat the size house that you are living in. You must also realize that not every house, stove set up is the same, let alone the temps we have to deal with.
 
  • Like
Reactions: fmsm
Will respectfully add my experience with HW v SW appears quite different from yours, and my outdoor storage has only been an issue once when some rodents (suspect chipmunks) took up residence. I do keep one ton over the summer and it does lose 5-8% heat output, but beyond that - no real issues.

Best,
- Jeff
 
  • Like
Reactions: Mt Bob
LOL,I have waited enough.Another case of a college educated idiot.So.lets start at hard vs soft wood pellets.All are shredded,chipped and chopped,then pressed.Softwood has resins,that burn,and are easier to create the pressed pellets.I sent this info to the OP.I can send more,if he requests it."fan speed and temperature", OP showed a 1 degree temp change,lol,that could be by the number of times you walked up and down the stairway."forced air and temp",OP really did not define this,we figured out he was/is using the duct system,to try to move the heat around.All of us figured out 20 years ago this is not efficient.he did not do his homework."fan speed and temp" sorry,I kinda skipped over that.A high quality pellet stove(which the OP owns)controls that feature and,one of the reasons the stove does that is for complete combustion,less wasted heat out the flu.Next-"insert hoppers"--OMG in a big house,are you so lazy to dump in 2 bags a day,for a room heater,trying to heat a huge house?Ever own a car in the 1970's that had a 12 gal fuel tank?OK,next,mini split-yes,I want one,would be efficient for 6 months of the year,out here,still a little cost prohibitive.Storing pellets outside--already proved that wrong,see above.Stove location--this I can agree with,a stove outside the hearth(fireplace) puts out more heat than an insert.Well,that is my rant,and I thank firepot and bach for the input.
 
As far as cost savings goes I think the only way to save anymore is if you are on propane or resistance electric. Natural gas is pretty cheap in our area and geothermal is minimal cost to run. Then if you try to buy a new Harman you have to take a second mortgage on your house!:)
 
  • Like
Reactions: Mt Bob
Storing pellets outside--already proved that wrong,see above.Stove location--this I can agree with,a stove outside the hearth(fireplace) puts out more heat than an insert.Well,that is my rant,and I thank firepot and bach for the input.

From your own link, "Ideally, your fuel is best stored indoors, like described above."
 
Last edited:
Will respectfully add my experience with HW v SW appears quite different from yours, and my outdoor storage has only been an issue once when some rodents (suspect chipmunks) took up residence. I do keep one ton over the summer and it does lose 5-8% heat output, but beyond that - no real issues.

Best,
- Jeff

What is your average relative humidity through the seasons?
 
LOL,I have waited enough.Another case of a college educated idiot.So.lets start at hard vs soft wood pellets.All are shredded,chipped and chopped,then pressed.Softwood has resins,that burn,and are easier to create the pressed pellets.I sent this info to the OP.

OK... How does any of this affect burn speed? How does any of this change hard woods burning better in my application, both in terms of BTU output and cleanliness?

I can send more,if he requests it."fan speed and temperature", OP showed a 1 degree temp change,lol,that could be by the number of times you walked up and down the stairway."forced air and temp",OP really did not define this,we figured out he was/is using the duct system,to try to move the heat around.

You mis-read what I said. The house never got above 70 degrees, period (i.e., sustained at 70, because the temperature would often dip to 66). Now I can easily get my home to 71 and keep it there or make it rise.


All of us figured out 20 years ago this is not efficient.he did not do his homework."fan speed and temp" sorry,I kinda skipped over that.A high quality pellet stove(which the OP owns)controls that feature and,one of the reasons the stove does that is for complete combustion,less wasted heat out the flu.

Harmans are not quality stoves?


Next-"insert hoppers"--OMG in a big house,are you so lazy to dump in 2 bags a day,for a room heater,trying to heat a huge house?Ever own a car in the 1970's that had a 12 gal fuel tank?

Do you still sell horse drawn carriages? Are you retired? How does someone load two bags a day when they are at work?

Totally agree that pellets are the cost of not paying the gas man. I just hauled 2 tons into storage.

Instead of spending $5k+ on an insert, te previous owner should have installed a supplemental pellet furnace to the existing electric forced air system.

OK,next,mini split-yes,I want one,would be efficient for 6 months of the year,out here,still a little cost prohibitive.Storing pellets outside--already proved that wrong,see above.Stove location--this I can agree with,a stove outside the hearth(fireplace) puts out more heat than an insert.Well,that is my rant,and I thank firepot and bach for the input.

This is wrong. Does your ambient weather drop to -15 degrees? If not, then you would have full efficiency with a mini split year round.

I would need a six head system. Just the system itself would run me $10K, plus all my installation materials. This is a bill I am not wiling to do right now.

I am currently looking at purchasing a used pellet furnace for coop operations with my present forced air.
 
My stoves love hardwoods (Cubex and Hamers). The one time I got some really high quality DF's, the P61a was like, yeah, okay, they are better than FSU's. But Cubex and Hamers were better (cleaner, hotter, could leap taller buildings :)). I also found that the DF's went thru very quickly compared to other pellets.

That being said, I get a better value out of mid grade pellets in heat versus cost. Ash is not much of a consideration since my ash pans are pretty good size and I can go 2-4 weeks between cleaning.

Hoppers size - yeah, I really like that my stoves have extensions on them. That is one reason I got the P43 to replace the Hastings that was on the main floor. In Jan & Feb the Hastings would run out on a regular basis before I got home from work (12-15 hours) even though I topped it off before I left in the morning. Of course the Hastings only had a 35# hopper (regardless that the literature says 40# - I could never get an entire bag in it).

I will just say that the same stove may perform differently from one address to another, never mind just the same model.

Exactly this - I know people that have a P61a who swear their stove dislikes HW and loves DF's. Others can heat their entire 3k/sq ft house without their P61a breaking a sweat. Or, can heat from the basement without any issues. Mine can't, but only because of the way the house is laid out and other vagueries of my particular circumstances.

So, as nice as it would be to flat out state, "this works and that doesn't," each experience is unique to particular setting, setup, install and owners' likes/dislikes.
 
Who is still making a pellet add on furnace?
 
Many unanswered questions that you left for the members here.

OK...

How long have you lived there and used that stove?

3 months.

Was the stove itself in the house when you moved in?

Yes, which is why I am sticking with it, until I buy a free standing stove or coop furnace, if I can find them for the right price; or go completely with a mini-split application. If mini-split, I would keep my insert for aesthetics.

Who installed it? What are the actual dimensions of the exhaust and fresh air intake (if you have a FAI) lengths of piping, horizontal and vertical

The local Harman dealer. 4" flue, 3" intake. Vertical pipe. Approximately 18" past the damper

When you changed the room fan setting how long did you wait to see a change in the temp of the other rooms?

Now, we are getting somewhere, boy-o. I have six EcoBee sensors in my home. I get the average temperature of the house (i.e., ambient temperature of all rooms averaged together).

Gave the stove three days and contrasted against the ambient outside temperature. Outside conditions were similar in both scenarios.

More info is always better for us that read this and will try and help. You say in the OP at the top of this thread that you are putting out info for people to learn what you have learned, then you have to also realize most of us are not trying to heat the size house that you are living in. You must also realize that not every house, stove set up is the same, let alone the temps we have to deal with.

Agreed.
 
Who is still making a pellet add on furnace?

Caddy and Pellet-ology (or something). I would prefer to get a used Harman. I keep an eye out for Craig's List postings in my area.

With that being said, I would need a furnace at the right price. I would not go above $1,000 for the unit itself.

Staying with pellets as the primary heating source does not add up knowing the cost of mini-splits for my home.
 
Watch out when buying a used Harman furnace. All the pellet furnaces I have serviced were in basements. I have seen several that were not in good shape do to moisture. Plus you would probably have as much in a used furnace /labor to have it hooked up as to just add another stove up stairs. I am not a big fan of the PF100.
 
  • Like
Reactions: FirepotPete
My stoves love hardwoods (Cubex and Hamers). The one time I got some really high quality DF's, the P61a was like, yeah, okay, they are better than FSU's. But Cubex and Hamers were better (cleaner, hotter, could leap taller buildings :)). I also found that the DF's went thru very quickly compared to other pellets.

That being said, I get a better value out of mid grade pellets in heat versus cost. Ash is not much of a consideration since my ash pans are pretty good size and I can go 2-4 weeks between cleaning.

Hoppers size - yeah, I really like that my stoves have extensions on them. That is one reason I got the P43 to replace the Hastings that was on the main floor. In Jan & Feb the Hastings would run out on a regular basis before I got home from work (12-15 hours) even though I topped it off before I left in the morning. Of course the Hastings only had a 35# hopper (regardless that the literature says 40# - I could never get an entire bag in it).



Exactly this - I know people that have a P61a who swear their stove dislikes HW and loves DF's. Others can heat their entire 3k/sq ft house without their P61a breaking a sweat. Or, can heat from the basement without any issues. Mine can't, but only because of the way the house is laid out and other vagueries of my particular circumstances.

So, as nice as it would be to flat out state, "this works and that doesn't," each experience is unique to particular setting, setup, install and owners' likes/dislikes.

Well said! How much was the P61? Did you go new or used?
 
  • Like
Reactions: bogieb
Watch out when buying a used Harman furnace. All the pellet furnaces I have serviced were in basements. I have seen several that were not in good shape do to moisture. Plus you would probably have as much in a used furnace /labor to have it hooked up as to just add another stove up stairs. I am not a big fan of the PF100.

Are there any considerations to be made when re-utilizing an oil flue for the pellet furnace installation? Is it still a damper installation from the furnace through the flue?
 
Well said! How much was the P61? Did you go new or used?
The P61a was bought new from a dealer. The stove was $3240 plus about $1,000 to install.

Edit - just remembered that $1,000 also included the hopper extension itself plus install of the hopper closure sensing probe.
 
What is your average relative humidity through the seasons?

As my profile points out in every post, I'm in central Massachusetts. So - "high", but perhaps for a month or so less of the year than you.

I do leave my "hold back" ton in factory wrap with a pallet cover over it, as I do with all my pending tons.

As for me, I burn softwoods almost exclusively because I dump my ashes once per ton and clean my stove* every couple years, whether it needs it or not...

Good luck,
- Jeff
*why yes, I do clean the flue/vent system every season, thanks.
 
  • Like
Reactions: bogieb
As my profile points out in every post, I'm in central Massachusetts. So - "high", but perhaps for a month or so less of the year than you.

I do leave my "hold back" ton in factory wrap with a pallet cover over it, as I do with all my pending tons.

As for me, I burn softwoods almost exclusively because I dump my ashes once per ton and clean my stove* every couple years, whether it needs it or not...

Good luck,
- Jeff
*why yes, I do clean the flue/vent system every season, thanks.

Are you near Southbridge? I spent six months there recently.
 
The P61a was bought new from a dealer. The stove was $3240 plus about $1,000 to install.

Edit - just remembered that $1,000 also included the hopper extension itself plus install of the hopper closure sensing probe.

That is a good price. Did you go with the 80lb hopper?
 
That is a good price. Did you go with the 80lb hopper?

I don't understand your question. I got the stove with the hopper that was on it - which the literature that came with the stove says is a 72# hopper (the P68 has the 76# hopper). Then I had them add the hopper extension (as indicated in the previous post) that gives it a total of 132# capacity. Maybe they've changed the configuration since then or given other options?