Hardwood Versus Softwood and the Heat Exchange

[ChrisinVT]

I guess I am wondering what opinions might be regarding the fly ash buildup on the interior of the pellet stove.

Burning Hot and BTUs are great but if the interior of the stove is collecting an insulating layer due to a particular pellet, might a lesser BTU pellet that does not coat the interior as heavily actually provide more heat being exchanged into the room than a higher BTU pellet.

Kinda wondering if people have found that the softwood pellets have a softer, clingier, more readily to coat ash than a hardwood pellet that may have a harder, crisper, less likely to cling, less coating tendency thus not insulating the heat exchange from the fire?

I've Burned Okanagan pellets for the most part recently ($249/ton) and just gave the stove a good cleaning and am currently burning PA Pellets ($249/ton) and then I have 6 bags of Inferno($249/ton) I was going to try. Curious if the ash 'build-up' will be different between the three (I'll clean the stove between the different pellets.) brands.

Might the build up be something that will inhibit my heat exchange?


Any thoughts on how the accumulation of ash on the interior might affect the heat exchange? Hardwood pellets accumulate less? Softwood less? Does it matter? Best BTU and Lowest Ash Build-Up Pellet out there is...?

-ChrisinVT

Englander 25-PDVC/55

 

[Bigjim13]

Last year I used hardwood pellets that I bought at Tractor Supply, Premier pellets. This year I found a decent price on an 80/20 hardwood/softwood mix pellets and that's what I have been using, Maine Woods pellets. So far I would say I have burned about 50-65 bags and have definitely noticed more ash with the softwood mix. It's hard to say if the heat output is better, i would say if anything its equal or maybe a little less.

I live in Southern VT, just outside of Rutland, and we have had some pretty cold temps here the last week or so and I have been running the stove non stop. I had cleaned it around the beginning of the month and there is a bunch of ash that has built up again already so I need to do another full cleaning here in the next few days. Definitely more ash though with the softwood, at least from what I can see anyway.

 

[krooser]

Generally speaking softwoods burn hotter and with less ash. Ask anyone who's burning Okie's or Bear Mountain pellets... these are premium western pellets made from softwoods. Bear Mountains will have 1/2 the ash or less than the oak/maple hardwoods I burned two years ago... the Okie's would be similar.

The secret to keeping the heat exchanger's cleaner is to run your stove on "high" at least a few time each week. I burn mine on 4-5 out of six for about 20-30 minutes every morning... keeps the stove cleaner by burning off deposits on the heat exchangers. Regular FULL cleanings and using a leafblower to suck out ash from behind the firebox also is important.

 

[wil lanfear]

Last year I used hardwood pellets that I bought at Tractor Supply, Premier pellets. This year I found a decent price on an 80/20 hardwood/softwood mix pellets and that's what I have been using, Maine Woods pellets. So far I would say I have burned about 50-65 bags and have definitely noticed more ash with the softwood mix. It's hard to say if the heat output is better, i would say if anything its equal or maybe a little less.

I live in Southern VT, just outside of Rutland, and we have had some pretty cold temps here the last week or so and I have been running the stove non stop. I had cleaned it around the beginning of the month and there is a bunch of ash that has built up again already so I need to do another full cleaning here in the next few days. Definitely more ash though with the softwood, at least from what I can see anyway.

I test burned the Maine Woods pellets last spring in my boiler, worst pellet I've burned, lots of ash, IMHO,not because of the softwood blend, it's because of the bark that is ground in with the fiber to manufacture the pellets. Try some of the softwood pellets from Vermont Wood Pellets, these contain no bark, I've had a tour of the plant showing me how these pellets are manufactured from the pine logs to the end results, pellets.

 

[imacman]

.....I've Burned Okanagan pellets for the most part recently ($249/ton) and just gave the stove a good cleaning and am currently burning PA Pellets ($249/ton) and then I have 6 bags of Inferno($249/ton).....

I'll be interested in seeing the results for the amount of flyash vs. heat outpu. I've heard good & bad about the PA pellets, but the Infernos are just a crap pellet....save yourself the work and just test the PA & Okies.

IMO, if you can get the Okies at the same price as the Infernos and the PA, it's Okies all the way.

 

[Mr Fixit]

It's been my experience that some stoves burn better with softwood, and some burn better with hardwood. However, having said that, there is a good reason that firewood used in woodburning stoves is almost always hardwood. Typically, hardwoods burns hotter and therefore cleaner, with less creosote buildup. From personal burning experience, I burn hardwood pellets in my Enviro Empress. In that stove, softwood will not even produce a flame on low fire, and the heat value difference between soft and hardwoods is substantial. All pellets will produce ash and the key is to use the tube rake regularly to keep the heat exchanger tubes clear because that is where 75% of the heat will be transferred out of the stove and into the room.

 

[mnkywrnch]

It's been my experience that some stoves burn better with softwood, and some burn better with hardwood. However, having said that, there is a good reason that firewood used in woodburning stoves is almost always hardwood. Typically, hardwoods burns hotter and therefore cleaner, with less creosote buildup. From personal burning experience, I burn hardwood pellets in my Enviro Empress. In that stove, softwood will not even produce a flame on low fire, and the heat value difference between soft and hardwoods is substantial. All pellets will produce ash and the key is to use the tube rake regularly to keep the heat exchanger tubes clear because that is where 75% of the heat will be transferred out of the stove and into the room.

If you take a look at "the hearth room" there are plenty of members who strictly burn softwood.I just finished burning a ton of hardwood pellets which were by far dirtier than the lg and spruce pointe softwood I'm using now.

 

[jtakeman]

It's been my experience that some stoves burn better with softwood, and some burn better with hardwood. However, having said that, there is a good reason that firewood used in woodburning stoves is almost always hardwood. Typically, hardwoods burns hotter and therefore cleaner, with less creosote buildup. From personal burning experience, I burn hardwood pellets in my Enviro Empress. In that stove, softwood will not even produce a flame on low fire, and the heat value difference between soft and hardwoods is substantial. All pellets will produce ash and the key is to use the tube rake regularly to keep the heat exchanger tubes clear because that is where 75% of the heat will be transferred out of the stove and into the room.

With all due respect Mr Fixit...but IF this is true in your case...you need to be burning a better brand of softwoods....I find the statement you made to be highly suspect and if you are burning a really good softwood pellet, I have yet to see a pellet stove yet that won't give you great results from them...and I am not just referring to my brands...

I am on my 3rd pellet stove, I have burned both softwood and hardwood pellets in each stove. And I have to agree with BTU. Some of the cleanest, hottest pellets I have ever burnt are softwoods. A good quality softwood will run with the good quality hardwoods and usually produces much less ash. Don't compare a mediocre softwood to a quality hardwood. You can't compare apples to oranges. The same would go for a mediocre hardwood going head to head with a good quality softwood.

Please don't bring the woodstove "Yankee" thoughts here. The compressing of the pellet takes the natural density issue's out of the equation. Once a softwood pellet is compressed into a pellet. Its fiber becomes the same density as the hardwood. There is a wood species chart out there that also has the BTU ratings per pound. You will see Douglas Fir is at the top of the list for BTU's produced per pound.

To the OP, As far as I know. Most stoves have scrapers for the heat exchangers and it is recommended by the stove manufacture to use it every day. All heat exchangers get ash build up doesn't matter what stove you have or what pellets you burn(yes some pellets more than others). But the point is the heat tubes will collect ash and need to be cleaned daily with the scrapper, And weekly with a vac in your normal stove cleanings. This keeps the stove in its most efficient state.