Horizontal or out and up?

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Feb 3, 2010
64
Virginia
ok here's the question . ive watched several videos and read several "how to " deals that say i can direct vent my multifuel stove( out the wall and with the downturn ( all with approved pipe) this looks the easiest and cheapest but will i have much problems with it? like sooting up my house ect? there aren't many power outages normally here so that isn't (shouldnt be) a problem. the side of the house im gonna put the stove on is the side that the wind blows the least from. also i was going to use the exhaust and fresh air combo thimble too. whatcha think fellers?
 
preacherbiggin said:
ok here's the question . ive watched several videos and read several "how to " deals that say i can direct vent my multifuel stove( out the wall and with the downturn ( all with approved pipe) this looks the easiest and cheapest but will i have much problems with it? like sooting up my house ect? there aren't many power outages normally here so that isn't (shouldnt be) a problem. the side of the house im gonna put the stove on is the side that the wind blows the least from. also i was going to use the exhaust and fresh air combo thimble too. whatcha think fellers?


If the stove you are getting is a truly sealed system then a straight out is fine as long as you use an OAK, otherwise you need the natural draft of an out and up vent.

Be sure to pay attention to the vent length information in the installation manual.

Do not skimp on this part of your install.
 
SmokeyTheBear said:
preacherbiggin said:
ok here's the question . ive watched several videos and read several "how to " deals that say i can direct vent my multifuel stove( out the wall and with the downturn ( all with approved pipe) this looks the easiest and cheapest but will i have much problems with it? like sooting up my house ect? there aren't many power outages normally here so that isn't (shouldnt be) a problem. the side of the house im gonna put the stove on is the side that the wind blows the least from. also i was going to use the exhaust and fresh air combo thimble too. whatcha think fellers?


If the stove you are getting is a truly sealed system then a straight out is fine as long as you use an OAK, otherwise you need the natural draft of an out and up vent.

Be sure to pay attention to the vent length information in the installation manual.

Do not skimp on this part of your install.

What is an OAK? ( pardon the stupidity)
 
preacherbiggin said:
What is an OAK? ( pardon the stupidity)

OAK is another name for the fresh air intake (Outside Air Kit).

And IMO, I think you should do the out & up.....Give yourself about 3-4' of vertical pipe...the stove will draft better.

My 2 cents.
 
preacherbiggin said:
SmokeyTheBear said:
preacherbiggin said:
ok here's the question . ive watched several videos and read several "how to " deals that say i can direct vent my multifuel stove( out the wall and with the downturn ( all with approved pipe) this looks the easiest and cheapest but will i have much problems with it? like sooting up my house ect? there aren't many power outages normally here so that isn't (shouldnt be) a problem. the side of the house im gonna put the stove on is the side that the wind blows the least from. also i was going to use the exhaust and fresh air combo thimble too. whatcha think fellers?


If the stove you are getting is a truly sealed system then a straight out is fine as long as you use an OAK, otherwise you need the natural draft of an out and up vent.

Be sure to pay attention to the vent length information in the installation manual.

Do not skimp on this part of your install.

What is an OAK? ( pardon the stupidity)

OAK :Stands for (outside air kit).On my Englander it was a separate flexible pipe that connected to the back of the stove going thru my exterior wall /basically it brings in fresh (outside)air to the stove for combustion,instead of using room air from inside the house.
 
Let me back up preacher and explain it like this.

Air goes in, fuel burns, smoke is created, smoke goes out the vent is how it is supposed to work. That is in fact what happens PROVIDED the system provides a forced draft. Which is almost all the time, however if the power fails, or the exhaust blower quits, the smoke will not be drawn through the system except by a natural draft. If there isn't a draft that pulls the smoke out the vent it can end up going out an air wash or the air intake. Which is bad for the house and the folks that live there.

An OAK in the horizontal case will prevent the smoke from entering the house as it also is a path to the outside. This is good for the house and the folks that live there.

If you maintain a clean stove then the natural draft that is set up by the out and up vent system will allow the smoke to still exit the stove via the vent.
 
good info to have. thanks fellers! ive got several friends that are going to go pellet/corn in the near future too and they all are asking me a bunch of questions like what ive posted. i tell the "ill have to ask the fellers on the forum.and as always you guys come through fast! A+ on the help!
 
I have a Quadrafire that is direct vented and have had the power go off several times with the stove in full stride. Never had an issue with smoke in the house, unless someone goes over and opens the door to see wassup.

The little Prodigy is also direct vented and it too was fine during the last outage.

I prefer the direct vent with the run being only about 18" from the side of the house.

Here is why.

The longer the runs the more crap that accumulates in the pipe and the harder it is to clean.

With a short horizontal and a 45 tun down, you simply unscrew the 45 and vacuum out the flyash that will lay along the bottom of the pipe.

Pellet stoves are a way of life around here and along with that goes the never ending cycles of cleaning and maintenance.


Morning ritual starts with clearing clinkers, fill the hopper and every 3 days, shut down, vacuum the beast out and wash the windows.

I would install one of the end caps that allow the exhaust to go down. Cut a piece of 3/16 mesh screen (Hardware cloth) and fasten over the exhaust opening to keep out rodents, birds and bees.

Just be sure to check the screen every week or so to make sure the mesh is not clogging with crap.

Having hive of bees move into your stove is a real PITA.

If you have a quadrafire or other auto lighter, evciting the little beasties is easy, just turn up the stat and watch the fireworks as the whole crowd comes out the pipe .

Been there done that. One summer we had a Hmmmmmmmmm in the stove.
Looked in with a flashlight. OMG a whole hive had moved in.

Glad nobody opened the door..

Good luck with your install.


Snowy
 
From the pictures posted on the forum it seems like a short horizontal run is just asking for soot stains on the house. It's cheap, down and definitely dirty.

In our area there are pretty frequent winter power failures. When we had a Quad 1200i heating the house it was connected to a liner up the chimney ~22 ft. If the power went out, we had no smoke in the house even though the burn pot was full of smoldering pellets.
 
That's a good one Snowy.

Where the smoke goes depends on the pressure differences and that frequently will have that smoke exiting into the house, best to provide it no option on that score.

In fact if the exhaust fan dies the convection fan will provide a sufficient pressure difference to start the smoke out the intake.

Various vent manufacturers provide a horizontal cap that has the screen all ready installed and you are correct about the need to check the cap for crap buildup on a regular basis.
 
Beeees were not amused when we turned the stove on me thinks.

The quad warmed up the pellets and the smoke rolled, then the flames flew and the bees went up in smoke too..


Years ago we used to have troubles with a downdraft issue with the fireplace in the old ranch house.

Once the fire died down late at night and if the wind was just right, the sucker would smoke into the room.

AACCCKKKKKKKKKKKKK nasty.

We added about 3 feet on the top of the chimney with a wind directed top hat and no more issues.

I run my stoves on low heat setting so much that I hate the long tall chimneys as they tend to get skunked up.

The Nut shells I burn have a lot of broken nut meats that give off some oily smoke at times.

No creosote issues but will leave some residue. The short horizontal pipe heats up well and dries out quick with a little hot burn time.

There is always a trade off with everything me thinks.


Best

Snowy
 
There are many people here smarter than me about this subject, but all I have read and seen, including my last 2 houses indicate that the most stable config is out and up, or straight up. Not saying "direct vent" does not work, but look at the installs that have been there for a couple of years of both types. Even my out and up leaves stains on the roof, as I burn from Oct to May in NE, pretty much 24/7. There are reasons seasoned installers will not sell you an installed stove w/ direct vent- check out the pics!
I also had a place once that because of the topography was nearly impossible to have fire ever left to die by itself- would always revert to downward draft as it cooled. It is not that much more difficult to clean a few extra feet of pipe once per year of burn. Try cleaning that burn off your siding.
 
Dealer installed our XXV stove (up & out) and we've added a hardware cloth "cap" to keep out bigger critters (birds, bats, etc.). That won't keep out bees in the summer (they'll go right through the hardware cloth), so we've built a solid cap to put over the end of the pipe during the summer months when the stove is not in use.
 
I will agree as far as "IF THE POWER GOES OFF" the tall stack will help a little to extract any residual smoke.

Now in practical application, Pellet stoves are a forced draft burner, with either an exhaust fan alone or with a combustion booster too.

The Quads have an exhaust fan plus a pre pot booster.

These fans do a great job at getting combustion gases out of the stove.

Now lets look at airflow.

The gasses coming out of the stove are in most cases, WARM at best. The Quads tend to be a little hotter even a couple feet away from the stove.

The farther the exhaust travels the colder it gets and cold air does not rise well and the longer the distance the harder it is for the stoves fans to push this column of air.

Also to be considered is tha amount of particulate that will gravitate out of the moving air column.

Horizontal runs collect a lot of fly ash and even over the course of one season of 24-7 running can fill the pipe up to 1/4 the diameter full of crud.


Specs usually say to terminate direct vents no less than 12" from the side of the building.

If the exhaust is in a place where its not going to be a nuisance (Trip hazzard head knocker) I prefer 18"-24" with the 45 angle cap on it.

The airflow velocity at these short termination points is still very high and with this comes good efficiency of the stove.


The Whitfields with single exhaust fan (and other brands too) need to keep the velocity of the exhaust fairly high as this airflow out is what pulls air into the burn pot and through the stove.


My answer is keep it simple and easy to maintain.

My only acception would be in the case of having to use an existing brick chimney and a flex liner to the roof top of the chimney.

I personally live in a Triple wide manufactured home that sits on a full daylight basement.

Now this sucker has more windows than you can shake a stick at.

Ty to find a wall, corner or ??? that will allow the vent to be the minimum of 4 feet from an opening .


Have 3 stoves now with direct vents for 15 years and zero issues to date.

Have one (Earth stove WP50) with a tall stack and its fine but far more work to keep clean.

PLUS once you head up you have to go above the roof line and this requires braces for the stack and this also means drilling holes in the roof to bolt the things to.

Possible leaks ???

I am redoing the install now on my Earth Stove. The Old WP 50 is coming out and an Advantage 2T is going in.

The old stack is all coming down and the new (to us) stove will be vented right out the wall and terminate 18" or so outside with a 45 angled cap on it.

Just my two cents worth.

Without a doubt, you must adhere to local codes and practices.

OH almost forgot, I looked, I dont have any stains on the house anywhere from smoke.
The nutshells I burn can at times (On low settings) smoke a little from time to time as the stove cycles from burn time to feed time.

If the auger happens to drop a slug of shells in and the fire "smothers" momentarily it will smoke a little until it catches again.


Snowy
 
Almost all venting setups work to some degree and under most conditions it makes little difference, however it is precisely the not so frequent conditions that cause the most harm when they occur.

We are talking about a device that can and does fail in a number of ways that can result in combustion byproducts being dumped into the house if you don't take some fairly simple very low cost steps.

I'll put my money where my mouth is in a situation like that.

I propose that KISS be now interpreted as Keep It Simple and Safe.


Now as is running around here in a sig some where somewhat paraphrased.

You are a big fuel burner now so I'm not going to tuck you in or leave the night light on.
 
Not looking to ruffle feathers at all here.

The only time that I have had smoke in the room is with the Old WP50 and it has a stack that goes out and up to above the roof line.

If the power goes off this is the only stove that will smoke up the house. Go figure.

The Prodigy is vented out the back right off the top of the stove and we have had two power failures and both times the stove was fine without any smell in the house.

Now there may be a reason here. The prevailing wind blows by the 45 angled pipe in a waqy that it may be causing some suction. ?????


Whatever makes you happy.

Good luck with whatever system you choose to use.


Snowy
 
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