Harman, high btu pellets needed?

[alternativeheat]

Nice Christmas story and thanks for sharing. You illustrate my comparison nicely.

It is Christmas Day and Merry Christmas to all ! This year the wife is not broken and that's a great thing ( still knitting but that's fine). We had family and friends in last night, I played piano, we ate lots of goodies etc. There is a phenomenon that happens here each year lately, my X wife comes to Christmas Eve celebrations here and she loves my piano music and of course our mutual grand children and two daughters. This was spawned by my present wife when my X was having a hard time and been carried on ever since ( she and her husband lost their business and retirement in the 08 crash, so she is now going on 61 and working two jobs and I don't think there is much end in sight.).

This winter I have two tons of DF waiting for Jan to hit. All is good.

Again, Merry Christmas !

 

[rona]

As it relates to all of the above, the ESP will max out stove production at 500 degrees. The stack temp will not be allowed to go any higher.

One point to consider about this is how much heat are you pushing out the exh pipe wasting it? I am of the opinion running a stove at 75% of its capacity is probably making the best efficiency out of the fuel you are using. Your convection tubes can only absorb and pass on so much heat after that it goes right out the exh pipe.

 

[alternativeheat]

One point to consider about this is how much heat are you pushing out the exh pipe wasting it? I am of the opinion running a stove at 75% of its capacity is probably making the best efficiency out of the fuel you are using. Your convection tubes can only absorb and pass on so much heat after that it goes right out the exh pipe.

With a Harman the max exhaust temp is 500 deg. the stove can't push more than out. So my view is the other way around, what isn't going up the pipe is available for heat to the house. But, is Harman utilizing that ? I don't know that answer but I know that when my P61 is running at about 2/3 output you don't want to sit too close to it. It kind of feels like you're getting a sunburn on your face. I never let it go to 100% output, only in my ash line burn and shut it back down as soon as I got the 1" line or perceived line. Anyway, real hot and yet we know the pipe temp was not over 500 deg. Draft is a combustion blower controlled feature in a Harman.

 

[SmokeEater]

Theoretically the PB 105 can burn about 8 bags of pellets per day at max output. GEEZ, I'd not like to see that. But I have seen more than 4. and at those burns, the exhaust temp would be at 200F. Never seen it go over that. My feed setting is at the point where I keep the high burn showing pellets at about an inch back from the end of the fire pot. The setting is at 5 of 6. It's my understanding that wood fiber of any source compressed into a pellet will have a heating value of around 8200 but/lb. And that the heat value varies little from that. I don't know of any high heat output pellets unless we are including torrified wood pellets. Considering the 8200 average, that means that no matter what the burn temperature is, a pound of average wood pellets will yield 8200 gross but/lb. I never change my feed setting and run the boiler temp to the max at 185 and min to 165. I also see no difference in any pellet tried, to it doesn't matter to the Harman boiler what pellet is burned, the performance seems to be constant. Ya gotta like that. So I buy what's least expensive.

 

[TonyVideo]

One thing for certain is I love my Harmans. They just keep working. I can throw any pellet type at them and they will burn fine. I don't have to keep an eye on it to make sure it is burning. Clean it once a week, scrape the pot once a day and they just keep on trucking putting out my desired heat. They have come a long way over the years. Now if I just had an app for my phone. It could give me exhaust temp, room temp setting, feed rate. Keep track of rate of pellet usage and what I have on hand, average cost per month and tell me when efficiency is dropping letting me to set a threshold when to clean. An outside thermometer with humidity to adjust accordingly as that would also effect combustion with an OAK and time at current rate when stove would shut off when out of pellets. Obsessed just maybe.

 

[yrock87]

Once again, the thanks for all the input everyone. So if 500 stack temp is the max temp alowed by harman stores, and assuming that mid grade or low grade pellets can achieve a stack temp of 500, that means that high btu pellets (9300 I hear quoted for df) would NOT provide more heat in a harman. They will not allow the stove to produce more heat. The esp temps would be the limiting factor and would dial back the feed rate.

I think this answers my question. With a harman, high quality pellets may lead to a cleaner burn or faster rise to temp or/and less pellet consumption. But it does not actually allow for a "hotter burn". This is because at the end of the day, stack temp as determined by the esp determines how many pellets are consumed.

As far as efficiently goes. No matter how efficient or inefficient my stove gets, it creates cheaper btus than the oil boiler. At $300 a ton vs $3.62 a gallon, pellets are the way to go.

I have used 50 Gallons a oil a month for the last three months. And almost a ton each month. That is running between 1.2 and 2 bags a day (out of a theoretical max of 2.4 a day) while it has been between 0 and +20. Next week to drops down to - 30 and i expect the stove to be at100% just trying to keep up with the oil burner picking up the delta.

It sounds bad, but compared to 3 deliveries of 300 to 400 Gallons each last year in the same time frame this is a godsend. Saving me $2500 from the same time last year.

Once again, Merry Christmas everyone, I had to sneak on here after the better half took a post dinner nap on the couch.
God bless and stay warm!

 

[F4jock]

One thing never ceases to amaze me. One gets a pellet stove that, if operated correctly, does everything but cook one's breakfast and immediately one wants to figure out how to push it beyond it's capabilities. Not that I wasn't guilty of this myself (You'd laugh if I told you all the stuff I tried!) but thru time I've learned to dump in pellets and enjoy the sophisticated performance of my Harman as it works flawlessly in the background. In short, it's become kinda like my refrigerator: I don't try to improve its performance. I just use it. BTW, now finishing week five with no major cleaning, another benefit of this horse. Use crappy pellets, generate more ash, clean more often, heat is the same.

 

[tjnamtiw]

Good one, F4 God save us from the Super Premium Platinum Miracle Pellet fallacy!

 

[F4jock]

Good one, F4 God save us from the Super Premium Platinum Miracle Pellet fallacy!

With High Speed Bumper Bolts!