best pellet stove pipe???

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rdubs20

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Nov 2, 2014
185
Northern NY
I am going to be installing a harman xxv within the next month and I was wondering if any pipe is better then the next. I'm just looking for the best pipe for my stove and would I need a 3 or 4 inch pipe. Also, what is the best way to install it? direct or with some sort of up and out or out and up configuration?
 
Best pipe can mean many things to many people. Some like selkirk DT as it has an OAK that pulls air in from around the actual inner vent. I have Bio-Vent which can come with the OAK that can be integrated into the section of pipe that goes through the thimble. Harman has a thimble that has an OAK integrated into the thimble. Selkirk and Bio-Vent also have standard pellet venting. There are other makers too...

As to 3 or 4 inch, what configuration will the venting be? Straight up, straight out, out and up? Sizing of venting depends on EVL (equivalent vertical length). 1' horizontal = 1; 1' vertical = 0.5; 90 elbow = 5; 45 elbow = 3. We can help walk you through that if we have more info... EVL of 15 or larger requires 4" venting.
 
If you will be running other fuels than pellets, then make sure you get pipe rated for multi-fuel. I use DuraVent PVP series as it is multi-fuel. Have only run pellets thus far, but my stoves are capable of burning almost anything pelletized, so could see myself changing up in the future. That pipe is more expensive than the DuraVent PVL (wood pellets only I believe), which is a perfectly fine pipe for just burning wood pellets. As Lake Girl said, it is a matter of what you will burn, and what features you want that will determine the "best" pipe.

If you have the choice, I would suggest up and out. That way if you lose power, the smoke should easily vent by itself. You will also recapture some of the heat lost out of the exhaust. If you are worried about aesthetics, you could go out and up (which should also vent smoke easily in case of power outage). If you are cramped on spaces, then direct vent would fill your need - as long as the stove install directions indicate it is safe to do so.

But while considering any piping install, you need to look at the configuration of the inside and outside of the house around where you are planning to install. There are clearance issues for doors, windows, corners, walkways, building spacing, eaves and just about anything else. The stove install manual, as well as the pipe manufacture should give you pretty good information on requirements.
 
I like Duravent. It’s a quality product and it’s extensively carried in places like Lowes or Home Depot which makes finding relacement parts easy if it ever became necessary.
 
I am mainly going to be burning pellets but maybe a 50/50 or corn down the road. If the pipe is a lot more then I would scratch that idea. I would definitely like to install an oak as well. I would like to do the top vent adapter but I read somewhere that it was only for masonry chimney's. I really like the look of the 6 inch wood stove pipe vs the 3 inch pellet stove pipe. Is there anyway that I can still use the top vent kit and simply use with a wall thimble?
 
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Burning corn, from my understanding, creates the most corrosive ash so you definitely would need the PVP (or equivalent in another brand).

I have no knowledge whatsoever on your 6" pipe question. I'll bet Lake Girl can point you in the right direction - either post wise, or specific members that you can PM for help in that area.
 
Just run a 3" liner up inside your existing 6" pipe.
 
Refer to the manual page 9 http://www.hearthnhome.com/downloads/installmanuals/xxv.pdf

Manual is very specific that the 6" be a sealed seam 6" flue pipe for connection to chimney... Not sure how that is handled if there is no existing chimney. May be able to get an adapter for 6" to 4" corn venting to go up and out but that would be a question for the dealer/installer.
 
does the selkirk dt work as well as a separate pipe and separate oak?
 
does the selkirk dt work as well as a separate pipe and separate oak?
I have the Selkirk DT on both my Harmans. It works better than the seperate OAK because it warms and dries the fresh air coming into the burn pot. I find the ash is fluffier and I do a lot less scraping of the burn pot!
 
I have the Selkirk DT on both my Harmans. It works better than the seperate OAK because it warms and dries the fresh air coming into the burn pot. I find the ash is fluffier and I do a lot less scraping of the burn pot!
Did you have OAKs set up before switching to the DT? It is my understanding that a given volume of air has a denser concentration of molecules when cold and actually yields more oxygen per volume. Should actually burn better with cold air...
 
Did you have OAKs set up before switching to the DT? It is my understanding that a given volume of air has a denser concentration of molecules when cold and actually yields more oxygen per volume. Should actually burn better with cold air...
Cold air with more oxygen only works better feeding internal combustion engines. They are very different than pellet stoves. In a pellet stove cold air takes more energy to warm it up and moisture in the air makes the ash stick together.
 
Cold room air requires more energy to heat but we are talking "combustion chamber" not circulating air. Combustion is combustion ... Had this discussion with the Hubby last year. He mentioned a Honeywell study from the 50s or 60s that mentioned cold air improved efficiency of burn on furnaces. No luck finding the study but haven't looked for a while.
 
Cold room air requires more energy to heat but we are talking "combustion chamber" not circulating air. Combustion is combustion ... Had this discussion with the Hubby last year. He mentioned a Honeywell study from the 50s or 60s that mentioned cold air improved efficiency of burn on furnaces. No luck finding the study but haven't looked for a while.

Ehhh if your stove is already burning effectively, excess 02(Air) is just going out the stack as heat, just like a boiler or furnace.

So if the above statement is true, the cold air is actually cooling down your combustion temperature, which is lost BTUs. For our boilers at work, they want the combustion intake air as hot as possible, because cold air is a BTU loss.

Similar to heating water from the city, if you start with 40 degree that it is going to cost you more than 70 degree water.

How much energy is lost is a whole different story.
 
well I am a little confused...is a regular oak better or is the selkirk dt design better???
 
How much energy is lost is a whole different story.

With our forced hot air oil furnace here, the rating is 78% vs. 83% in the manual, or a 5% burn efficiency increase for pre-heated air going into the combustion chamber.
 
well I am a little confused...is a regular oak better or is the selkirk dt design better???

They are both equal.

The benefit of Selkirk is it MIGHT save you some $$$ on pellets due to efficiency gains. Also you don't need to cut a second hole for OAK.

If you have room to cut an OAK, I would just go with the cheaper route. I used Duravent myself.
 
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With our forced hot air oil furnace here, the rating is 78% vs. 83% in the manual, or a 5% burn efficiency increase for pre-heated air going into the combustion chamber.
Thanks for that info.

I have heard Selkirk DT oak is 10% more efficient but 5% may be more realistic.
 
Hi Don, it may well be more, the FHA furnace moves a lot more air vs. a given pellet stove, that has to lower the pre-charge temp. of incoming air which directly relates to combustion efficiency. Just sounding out here - I like to keep informed, but in the end I'm just another geek roasting pellets to stay warm.. :)

I'm in the same boat w/ the new OAK here, been pulling house temp. air into the stove all winter - I know the Ecoteck will need to be re-tuned, how much remains to be seen.. A fair amount, I suspect.

Started working on the automatic FHA vent dampners, the wife thinks I've gone off the deep end.. Schematics, stick figure drawings, and wiring all over the place. I think she may be right.. I gotta get back outside and do some yard work.
 
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how much is the selkirk DT? And where can I buy it?
 
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