I am marginally disapointed in pellet stoves at the moment.

[stoveguy2esw]

here's a theory , not sure how much impact it has on your situation bro , but here it is.

in a higher altitude low humidity situation , radient heat (which heats up not only the air but the surrounding surfaces) is going to do what its going to do heat said surfaces. convective heat is supplying heat to the air , not to the surfaces , now since you are high and dry so to speak , there is less "air" going through the stove into the room , even the humidity in the air gets heated to some extent. so convection without as much substance to "convect" means a lesser transfer of energy per BTU released due to the method of transfer.

make sense????

if im right , you would realise much more result from the radience of a woodstove and less from strictly convective heat , therefore the lesser performance. just a stab in the dark mind you , but it makes sense to me though i havent studied it out fully.

That is really really really good. I tell you i learn something new here everyday. I have never tried to heat in a humid environment, so i would have no basis to compare to. It is so dry where i live, you can leave a bag of potato chips on the counter open, for two weeks, and they do not get stale. Dont ask me how i know :roll: You add that to the altitude, (9000+ feet) and that could be a bad combination for a pure convection stove.

give the credit to POOK , had he not started on that tangent about mold bringing you to mention the "high desert" thing , i wouldnt have thought about it that way, theory was strictly off the top of my head , i dunno if someone has published similar though i might look around for it sometime. guess you caught the gist of what i was thinking anyway. BTW im flattered by your reply.i consider you to be a very smart guy, so im taking that as a complement if ya dont mind ;-)

DUH, TOP OF STOVE IS STILL RADIATING AT CEILING pstove radiates into chamber where blower converts to convective & delivers sideways & towards floor like my 25 pdvc= i disagree but weigh the wood & pellets on your way. BTW wheres the specs?

his model is not as good a radiator as the pdvc due to the pdvc having a lot of the firebox exposed to outside, its still a great stove though more of a "true convective" design so your stove having that one sheet of steel between the fire and the room gives off more radience. also , you are in a more humid more air dense area than he is so there is more "stuff" coming out the vent at your house than his. the more density in the air the more transfer you get due to more molecules to reatain and carry heat, simply more molecular surface area in denser air. at least thats the gist of my thought on it. as for spec's i'll check again , but remember corie is a busy lad with a lot on his plate, he likely has forgotten my request.

burn the pellets & u get x heat via molecular agitation. does the thinness of the air make the diff or the humidity, or do the pellets produce less heat?
the top of the woodstove still radiates at the ceiling,eh?

exactly right in one part , molecular agitation , or retainment and release of energy , the difference is the delivery system , pellets pound for pound contain the same base storage of energy as log wood does roughly 8500 BTu per LB remember pellets are still just wood so the same thermal energy released from consuming a 1 lb block of wood is released by consuming 1 lb of wood pellets. the diference with pellet stoves is the energy is channeled and released under different methods than wood (or log) stoves utilize. the more surface area that comes close enough to the radient heat inside the exchangers of a pelet stove , the more heat is absorbed per cubic measure of air then moved into the open airspace of the room. with a log stove , the whole skin of the stove is the heat exchanger so more molecules come into contact or close proximity to absorb heat also the heat exchangers in a pellet stove are internal for the most part so radience is trapped somewhat by the outer shell of the stove with wood it transfers through directly into a room which is why if you think about it , a wall protector works as it does , and why you have to keep an opening at the bottom, heat radiates onto the wall surface transfers through and into the airspace , but the resulting updraft from the heated air in the space allows heat to be carried out the top and the resulting vacuum pulls more cold air in to absorb the "next " heat in a constant moving current.

and to think i used to hate physics somewhere out there my high school teacher is smiling

 

[MountainStoveGuy]

Thats a idea too. I have my stove hooked to my class A chimney using the top vent kit i bought from harman. So 6" all the way up!

 

[slow-al]

Being a dealer what reports have you gotten from customers? Or do you mostly sell conventional wood stoves?

Do you have a humidifier? Reports I've been told by users is the cold water type are more effective than the heated style.

 

[stoveguy2esw]

yes evaporation is a cooling function , however you have to have a change in the relative humidity within the heated space without sending the heated air through the heat exchanger area to cause a heat loss in that case due to dissipation into the cooler moister air which is able to absorb it, the humidity though sparse is a constant fire creates moisture but its within a sealed system in both cases so it doesnt come into play, still at the molecular level water molecules have heat retention capability just as oxygen and other gasses do , if the stove were "sweating" it would lower its internal temperature but this would not dissipate heat except into the surrounding air , which is convection in itself in a way so not real heat loss would occur within the air in an enclosed space.


man what a great thread though

 

[Corey]

You brought up an interesting point initially - a constant 50K btu pellet stove vs a variable 80K btu wood stove. But what temperature are wood stoves btu output actually rated at? Though I don't know about a wood stove as a whole, generally radiated energy increases as the fourth power of temperature. Consequently - if a wood stove is rated 80k btu at say 500F surface temp and you run it at 600F, you don't necessarily get a simple linear increase in output, but could be something moderately higher. You may have been burning you 80k wood stove at 100-120k btu or more.

Assuming roughly equal efficiency, I'd expect you should burn roughly equal pounds of pellets or wood - does that look like it will be the case?

 

[BJN644]

Being a dealer, any way you could try a P68 out? I think the P series throw more radiant heat than the XXV. Just a thought.

 

[DeePee]

Psychrometric Chart @ 7500ft

Psychrometric Chart @ Sea Level

Interesting lecture about enthalpy.

 

[stoveguy2esw]

Psychrometric Chart @ 7500ft

Psychrometric Chart @ Sea Level

Interesting lecture about enthalpy.

peeked at the links , i'll look at them in depth when i have a while to devote to it , the lecture looks like a good one in a quick peek , but its an hour long , will have to wait maybe if its dead at work i can take a peek. thanks for the links though its interesting stuff

 

[iceman]

i have/had pellet stoves ... trying to heat a house the rule for me is 1 ton a month dec -feb .. march-april 1 ton +-
sept-nov 1 ton+- so if its a mild winter 4 tons cold winter 5-6... thats why i stopped using them as much ... for all the work vs saving money it was better to run my furnace...... once you go over 1.5 a day you need to weigh out which is cheaper... also i DONT USE ROOM TEMP SETTING.. why? because sometimes its hard for air to move and the room the stove is in might be 75 but down the hall could be 60... so i leave it at 1 setting all the time that would keep the area warm AND i knew how much pellet consumption.... also when temp goes up to 50 during the day it is still running because its going down to 30 at night... its easier to open a window in one room than try to raise the temp up in a whole house....
you will need more than 3 tons ......
also a 6 inch pipe might be to big ... it will burn very good but ps require pressure and if not enough back pressure all your heat will go up faster thus ot giving off more in the room..... i always thought stoves never wanted to more than a 4 inch... but i am not sure...

 

[MountainStoveGuy]

guys and gals. just got home from the one hour commute. The posts are fantastic. I am going to go through each one, look at the links, and get back to you guys in the morning. This is really really helpful. Thanks to all that have replied. Cozy's engineering analysis is something i am going to have to look at. Dee Pee's links look very interesting. ICe, thanks for the insite on usage. I think i am way way off. As a dealer i hear very few complaints, but most peeps that buy pellet stoves have always had pellet, and vice versa. As for now. Im completely exhausted and the three year old wants to "hang out" as she puts it.

A very sincere thanks to all.

-MSG

 

[MountainStoveGuy]

also, any one want to decipher those charts for me? Ironic, i sold solar to the company that produced those charts lol.

 

[rowerwet]

this thread makes me real glad my pellet stove uses hot water and baseboards to evenly heat the whole house.

 

[Delta-T]

MSG- I have one suggestion....stop using "room temp". Use "stove temp" mode, put the knob to 3.5 and wait a few hours. I would have told you right from the get go that you'll likely use 4 tons. Apples to apples you are not going to get 80K BTU from a 50K btu max appliance, this we can all agree to. Chances are, the XXV doesn't beleive you are even asking for 50K unless you put that sucker on stove temp and turn the knob to 7. YOu can check you exhaust temp with the DDM and with the fuzzy logic in the brain it should never let itself become inefficient. YOu may have excessive draft, but I assume, because you are a dealer , that you have set the minimum draft and that it is acceptable. There is a 3 week learning curve in my opinion, even if you have boat loads of knowledge (which I know you do). Its the actual application of that knowledge, in real world, that takes time IMHO. The laws of entropy are extremely complex and are hard to try to decifer, but in the end, I think you just aren't conveying to the machine what you'd like, in a language that it can understand. If you are in room temp the stove attempts to heat until the room temp probe is satisfied, that is all. It cares not for your bedroom of your pantry, just the probe. Stove temp will dictate to the stove to burn pellets at a constant rate, and therefore constant even output of heat. You should find this more to your liking. One you have established a stabile temp and your house becomes a thermal mass, you can then switch to the room temp if you so desire and hopefully you will find that it is also, more to your liking. I'm a huge fan of the stove temp, and very rarely (read never, unless told to do so) use the room temp mode. ONce you estabnlish what setting (1-7) works best, you may only need to tweak it slightly during different times of the day, or very different outside temps. PS- Make sure your feed adjuster is set to 4-4.5, no joke.

 

[MountainStoveGuy]

Delta, i agree completley. I have set the minimum draft set, and i will run it in stove mode. (at least at night). Like i said in the beginning, i am not writing this stove off just yet, just expressing my first impressions and how they apply to my application. I am very glad i have installed this unit. It will make me a better hearth professional. Most of the people i have worked with in the past in the shops never had any appliance that they have tried first hand. First hand knowledge is key.

Right now i have the feed set to 4.0 and the stove set to stove mode. Im pretty toasty this morning. THe stove ran out of pellets overnight, DOH!

 

[Dougsey]

Waiting for BTU to tell us why this stove is not producing enough heat....

 

[CarbonNeutral]

While your year round humidity (and shoulder season humidity), will be much lower than ours here in the NE, I would bet we're similar in the really cold periods.

EDIT: Nope, I'm wrong - on a relative humidity scale you are still much drier in winter even given similar temps (looking at Denver): http://www.engineeringtoolbox.com/us-outdoor-design-temperature-humidity-d_296.html

Interesting the relative humidity in winter and summer is not much different here - certainly you can feel the difference between the absolute humidity

 

[Clay H]

subscribing.....

 

[CarbonNeutral]

While your year round humidity (and shoulder season humidity), will be much lower than ours here in the NE, I would bet we're similar in the really cold periods.

EDIT: Nope, I'm wrong - on a relative humidity scale you are still much drier in winter even given similar temps (looking at Denver): http://www.engineeringtoolbox.com/us-outdoor-design-temperature-humidity-d_296.html

Interesting the relative humidity in winter and summer is not much different here - certainly you can feel the difference between the absolute humidity

Ah, but hang on, (arguing with myself again) we're concerned about indoor humidity, so given the lack of available water in the air and the higher temperatures inside (borne out by the way my wood doors on my entertainment center shrink), then maybe the relative humidities inside our houses in the coldest months are similar, or similar enough....

 

[MountainStoveGuy]

It is dry enough here that food does not go stale, it will eventually just pertrify. Mold? No way, mildew? no way. When it snows, the snow is so dry that it floats around like dust. We average around 15-20 inches a year of moisture, and that includes the 140+ inches or so of snow. Not sure how that works out. I have never used convection heat, but it does make sense that with less humidity, you will have less "mass" in the air to hold heat. This is making alot of sense now. Actually i just looked it up.

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual
Average Max. Temperature (F) 34.3 36.5 40.7 49.2 59.1 69.6 75.3 72.8 65.9 56.0 42.9 36.4 53.2
Average Min. Temperature (F) 13.7 15.3 18.2 24.1 32.3 39.7 44.5 43.3 36.9 29.3 21.0 15.8 27.8
Average Total Precipitation (in.) 1.12 0.96 1.81 2.35 2.69 2.16 2.34 2.09 1.52 1.24 1.28 1.22 20.79
Average Total SnowFall (in.) 19.1 14.8 27.2 22.4 9.4 1.4 0.0 0.0 3.2 9.5 16.7 16.2 140.1
Average Snow Depth (in.) 3 3 4 3 0 0 0 0 0 0 2 3 1

 

[CarbonNeutral]

It is dry enough here that food does not go stale, it will eventually just pertrify. Mold? No way, mildew? no way. When it snows, the snow is so dry that it floats around like dust. We average around 15-20 inches a year of moisture, and that includes the 140+ inches or so of snow. Not sure how that works out. I have never used convection heat, but it does make sense that with less humidity, you will have less "mass" in the air to hold heat. This is making alot of sense now. Actually i just looked it up.

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual
Average Max. Temperature (F) 34.3 36.5 40.7 49.2 59.1 69.6 75.3 72.8 65.9 56.0 42.9 36.4 53.2
Average Min. Temperature (F) 13.7 15.3 18.2 24.1 32.3 39.7 44.5 43.3 36.9 29.3 21.0 15.8 27.8
Average Total Precipitation (in.) 1.12 0.96 1.81 2.35 2.69 2.16 2.34 2.09 1.52 1.24 1.28 1.22 20.79
Average Total SnowFall (in.) 19.1 14.8 27.2 22.4 9.4 1.4 0.0 0.0 3.2 9.5 16.7 16.2 140.1
Average Snow Depth (in.) 3 3 4 3 0 0 0 0 0 0 2 3 1

It's the reason that many people die in deserts due to cold rather than heat - no moisture to maintain temperature when the sun goes down

 

[tinkabranc]

It is dry enough here that food does not go stale, it will eventually just pertrify. Mold? No way, mildew? no way. ......

Sounds like a whole different world there compared to here.
I still can't get over the fact your chips don't go stale :lol:

 

[MountainStoveGuy]

I am originally from galveston island. I know humidity. You leave chips out for a hour down there they are disgusting.

This altitude makes cooking interesting too. Water boils at like 198* so things take alot longer to cook. Lots of weird things go on at 9000'.

 

[MountainStoveGuy]

there is no OAK, not yet. That might make a diff, but i am pretty convinced that radiant heat works better in altitude and dry climate then convection.

 

[Delta-T]

i was also going to mention the altitude and pressure differential. Even if you could maintain a higher humidity, say, similar to the NE, water gets to boiling and doesn't get hotter unless pressurized. Boiling at less than 212 is freaky, its giving my the willies right now, LOL.

Sure theres enough O2 at that height to burn pellets? (thats a joke)

 

[Clay H]

I think the simple solutions is you replaced a large stove with a smaller one...40% smaller.