Pellet Stove install questions

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escyr

Member
May 5, 2021
23
Southern Maine
Thanks to all who help me with my decision on pellet stove vs wood stove.

Now that I'm looking to have a pellet stove installed, I have a few questions on flue piping and location.

When our home was build 5 years ago, we had planned for a wood stove, so the home was prepared by having a chase left between the 1st floor and 2nd floor to run the wood stove flue pipe. Now that we've decided on a pellet stove, should I forgo running the stove pipe up through the 2nd floor, into the unconditioned attic and out the 12/12 pitch roof and just direct vent the stove pipe out the wall?

Also, I've been told that pellet stoves don't produce much radiant heat. The location we had planned for our wood stove was centrally located between our dining room and living room but facing into our living room. Would it be better to have the pellet stove in the living room facing our open kitchen/dining area, which would also face our open stairway to the 2nd floor?
 
Also, I've been told that pellet stoves don't produce much radiant heat.
Really depends on the stove.
My P68 gives off quite a bit of radiant..

Especially when ramping up.

lacrete_heat1.JPG

Dan
 
If it were me I would go up and out the wall forget the chase
less pipe = less money
But I am tight as a ducks ass and that's watertight
 
johneh is correct....I have a P61 and it radiates heat quite well also
 
We are all tight on here. Why we use alternate heat. Me, I'm really tight as in free corn. Another vote for through the wall. You want the venting to be as direct as possible and venting is expensive anyway.
 
Well that's easy when everyone agrees.

Any pros/cons to going straight out the back of the stove thru the wall as opposed to going up 4' then out the wall?
 
I'm in favour of the up 4 and out makes it look
more like a traditional wood stove. Some
people prefer the straight out for ease of cleaning
 
Also if you go up then out you’ll be getting a bit more radiant heat and there are thimbles that have cutouts for the air intake
 

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Quick question. For those that go straight out with the venting....
What happens if you change stove's in the future? The next stove outlet would have to be even or if anything different, lower than the current venting configuration. May be worth a thought while in the planning stage?
 
Whatever you do, just keep in mind that the more convoluted the exhaust gas path is, the more restricted the flow is. Far as different heights are concerned, that is what brick pavers are for and what I did when I replaced my old one for the new one years ago.

Had to raise mine about 4". The other thing is, you want the cleanout Tee outside, versus inside. Fly ash in the venting is messy and the venting will have to come apart for cleaning. Fly ash has a nasty habit of clinging to painted / finished surfaces.
 
Having the vent with a 4 or 5 foot rise before going out helps ensure a draft would still be present in the event of a power outage - so if you're in an area with potential for outages (without an automatic backup generator) it can be very helpful. That, and potential future stove changes (not all stoves have their vent outlet in the same place) are the main reasons I would suggest up and out to a horizontal cap.
 
In reality, you don't get very much natural draft from a 3" diameter vent pipe anyway. Maybe enough to suck some smoke out but not much in reality. One reason I went to 4" with a 3-4 increaser cleanout and 15 feet of vertical 4" vent. Even that don't 'suck' very hard.
 
I want to purchase my stove soon and I'm getting varying and conflicting information from the different stove shops that I've asked to quote my Harman Absolute 43 with installation. Hopefully you guys/girls can help clear some things up.

I'm still trying to decide between straight out the back of the stove and then up the outside of the house, or up inside then out horizontally to a nozzle. I have an operable window on the 2nd floor above where the vent pipe is going to be and from what I understand in the installation manual, I have to be at least 12" below this window if using an outside air kit, which I am. That leaves me with a max of ~8' of available vertical run.

If I go up inside, I could go up 1-2', then out horizontally, then up again 4-6' OR I can go up inside 3-5', then out horizontally, then up again another 2-3'. The first scenario appeals to us more because we don't particularly want the stove pipe showing in the house.

If I go up outside, I could go up ~8' before I have to put on a 90 with a cap/nozzle.

I also plan on using 4" pipe whichever way I do it to get as much draft as I can.

Will I be able to get enough draft to stop any smoke intrusion in case of loss of power in any of the above scenarios, or should I get this out of my head? I do plan on having a battery backup, like an APC UPS, and we do have a portable generator that I connect to the house if we lose power for too long. How long does it take for the fire to die upon loss of power?

If I go up a bit inside the house, do I need a cleanout tee inside, and outside of the house at the bottom of each vertical run? I don't know how often and how these pipes are to be cleaned.

Thank you and Happy 4th of July tomorrow!
Eric
 
When the power goes out and with an OAK installed you would get 0 smoke in the house
In 99% of installs.
You do not need to go up inside or outside. A termination nozzle is OK straight out
A UPS is desirable for power outages as it allows the stove to shut down normally
A Geny is also a good idea for longer power outages outages
My preferred piping is inside up to near the ceiling turned to outside and terminated
 
First off, 'nozzles' go on the end of a garden hose, not a biomass stove. It's a termination cap. secondly, no pellet vent will produce adequate draft to expel smoke, not in the cards and thirdly, you always want to place a cleanout Tee on the exterior of a dwelling (if at all possible and sometimes it isn't and I realize that) but an outside cleanout eliminates to a great extent, the mess associated with cleaning the venting and fly ash getting on everything in your dwelling. pellet vent will produce a tiny amount of natural (temperature differential draft) but not enough to be worthwhile in a forced shutdown situation. Why all solid fuel appliances (pellet / biomass stoves are forced draft in the first place.

I believe you will discover quickly that the price of appliances as well as install costs are going north at the same rate building materials are and I also suspect the availablity of units this year will be tough due to the disrupted supply chain.

I'd say, based on current trends, you'll see about a 25% across the board increase in hard parts and who knows what pellets will cost this year. I do know one thing and that is, they won't cost what they averaged last year for sure.

Finally, keep in mind where a lot of the replacement parts and hard parts come from and it ain't onshore either.
 
When the power goes out and with an OAK installed you would get 0 smoke in the house
In 99% of installs.
You do not need to go up inside or outside. A termination nozzle is OK straight out
A UPS is desirable for power outages as it allows the stove to shut down normally
A Geny is also a good idea for longer power outages outages
My preferred piping is inside up to near the ceiling turned to outside and terminated
Not mine but then we all have our preferential installation.

I take it the new nomenclature for a termination cap is a nozzle? Had a bad enough time on this site calling a Fresh Air Kit and Outside Air Kit. lets not further muddy the water.
 
When the power goes out and with an OAK installed you would get 0 smoke in the house
In 99% of installs
I disagree with your premise. All the outside air kit does is allow combustion air into the firebox so the appliance don't use ambient (heated) air for combustion and does little to nothing so far as exhausting smoke from an aborted firing. Smoke production and exhausting of that from an aborted firing is entirely dependent on the venting and what little natural draft it's capable of generating which is why it's always prudent to have a backup power supply to the unit, whether it's a standby generator or a a battery backed APS unit....

and a quality surge suppressor on the input line cord as well.
 
I appreciate the responses.

I have to go up to meet the 6’ clearance to a mechanical air inlet that is 4’ away horizontally.

Well, after researching how to clean pellet stove vent pipeI can understand why people vent directly out the back and then up with a clean out tee! What a mess that can be. Half of the videos I viewed had 1/4-1/3 of the horizon pipe full of ash. I never realized there was so much ash that had to be cleaned out and the more complex the vent pipe run, the more work it’s going to be.

Is it normal to have 1/4-1/3 the horizontal pipe full of ash after 3 tons of pellets?
 
In one word NO
What you see is people who do not follow
the recommended cleaning of their stove and chimney.
I may get 3 cups of ash after a season of burning
around 4 ton of pellets. But everyone will have different
results depending on stove, chimney installed, pellet type, and manufacturer.
 
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In one word NO
What you see is people who do not follow
the recommended cleaning of their stove and chimney.
I may get 3 cups of ash after a season of burning
around 4 ton of pellets. But everyone will have different
results depending on stove, chimney installed, pellet type, and manufacturer.
I agree and disagree. It all depends on the ash produced by the pellets and to a lesser extent the number of directional changes the vent pipe makes before it gets to the exhaust termination. The more convoluted the exhaust path is, the more restricted the exhaust gas is, the more suspended ash drops out in the venting.

Have to clean mine twice a season and... I use 4" vent pipe, not the usual 3". I also have mine set up with a straight shot out of the appliance to a 3-4" increaser with a cleanout on the bottom and a vertical run of 4" vent pipe 18 feet vertically with a termination cap on top. I do that to clear the top of my hip roof.

Unlike most on here I roast field corn and pellets and corn makes more ash but the corn is free for me so I run it. I only mix in pellets to reduce the clinkering effect of the corn. I don't recommend running corn for a couple reasons. Availability locally, the always residual nitric acid vapor (that corrodes the inside of an appliance without proper and ongoing maintenance and that most pellet stoves are physically incapable of running shelled corn in the first place and I believe that includes Harman stoves.

If you think for a minute that a stove is plug and play, you'll be sadly disappointed because they aren't. Might be plug and play for a month but then the grief will start and you'll be on here looking for a solution to your issues.
 
When the power goes out and with an OAK installed you would get 0 smoke in the house
In 99% of installs.
You do not need to go up inside or outside. A termination nozzle is OK straight out
A UPS is desirable for power outages as it allows the stove to shut down normally
A Geny is also a good idea for longer power outages outages
My preferred piping is inside up to near the ceiling turned to outside and terminated
I have to ask something personal... Are you a bachelor? If I had a setup like that (with the cleanout Tee inside the house) and I popped the cleanout cap and all that fly ash came out and got on the walls and floor, my wife would divorce me (after I was forced to clean up the mess)..... :eek:
 
"How long does it take for the fire to die upon loss of power "

The fire doesn't take long to go out - it is the smoldering that will go on forever (20-30 minutes), and that is the part that produces the worst smoke. Smoke will go the path of least resistance if it isn't forced out thru fans or assisted with a good draft. And if there is a power outage right as the pellets start to smolder or flame during start up, I don't care how good a vertical run you have, the exhaust pipe hasn't warmed up enough to really help the draft go (BTDT with the P61a which has 4" pipe and 5-6' vertical run with only two 45* angles). So, having the UPS or a generator is an excellent idea.
 
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