Fresh Air Intake or Outside Combustion Air

[BillX]

Hello Everyone:

I'm new to this forum and am looking forward to connecting with other users. I'm confused about one issue. I have a Piazzetta Sabrina stove installed in the basement.

The dealer that installed the unit didn't put either a fresh air vent or an outside air intake. I'm not sure either is necessary but it's not running that well (creating clinkers very easily). I have adjusted the combustion fan to a higher setting on all levels which will require more of a demand for fresh air (as well I reduced the auger feed rate).

I'm thinking of a fresh air pipe, possibly 3" to maximize the flow, which shouldn't be that hard to do. I'm trying to get a hold of a micromanometer as I'm doing all of this blind at the moment.

Any suggestions would be appreciated.

 

[johneh]

Welcome to the forum !
OAK (outside air kit) . The opinions on this forum are like
noises everyone has one . Mine is yes put one in. I have an oak
because I do not like spending money to heat air witch without a
OAK is being sucked into the stove and sent up the pipe to the
cold ,cold outside
Let the opinions roll

 

[BillX]

Welcome to the forum !
OAK (outside air kit) . The opinions on this forum are like
noises everyone has one . Mine is yes put one in. I have an oak
because I do not like spending money to heat air witch without a
OAK is being sucked into the stove and sent up the pipe to the
cold ,cold outside
Let the opinions roll

I'm thinking that would be the best option since it is in a basement and negative pressure is an issue.

Although a kit seems to be more than I need. A simple 3" pipe vented to the outside coming off the attached pipe from the stove should do it. I now have to work out positioning. It seems the instructions want the incoming and outgoing near each other, with the incoming below.

I really don't know why they are asking for it that way. Need to do more research.

 

[Pete Zahria]

Womaus line 2.........

 

[womaus]

Womaus line 2.........

Ding ding ding! This is the first of the season! Yay!

All frivolities aside....

There is no need to have the OAK inlet and the combustion outlet near each other if it is convenient of you to run another configuration. The inlet does nothing more than provide unconditioned outside air for combustion purposed, negating the need to use heated interior air.

You do not want to have excessive length on the inlet pipe unless you increase the diameter of the pipe. That may play into the install location.

You do not want to have the inlet above the outlet on the outside of the house, for obvious reasons.

In my own install I was able to find a Harman wall vent that combined both in one unit. It worked out well, the intake vent on the outside of the house is approx 4' off the ground, lots of height for snow pileup clearance unless we get another real bad winter. I've got a picture of it somewhere...I'll see if I can post it.

 

[BillX]

Thanks Womaus. That is a big help. The exhaust outlet is just in from the building corner by 20" and I was going to put the incoming around the corner about the same distance or slightly more from the corner. I know gas furnaces require that the incoming and outgoing venting must be the same length. It seems that that is not an issue with a pellet unit, although I don't know the reason.

The Piazzetta Sabrina manual says is should be a metal pipe. I was planning a 3" pipe although the stove opening is only 2". Not sure I need to buy a kit as it's a simple piping job. There is the issue of preventing moisture build-up within the walls to I'm guessing I have to leave a hole big enough for insulation wrap.

Thanks again.

 

[womaus]

Thanks Womaus. That is a big help. The exhaust outlet is just in from the building corner by 20" and I was going to put the incoming around the corner about the same distance or slightly more from the corner. I know gas furnaces require that the incoming and outgoing venting must be the same length. It seems that that is not an issue with a pellet unit, although I don't know the reason.

The Piazzetta Sabrina manual says is should be a metal pipe. I was planning a 3" pipe although the stove opening is only 2". Not sure I need to buy a kit as it's a simple piping job. There is the issue of preventing moisture build-up within the walls to I'm guessing I have to leave a hole big enough for insulation wrap.

Thanks again.

I'd just use the 2", I don't think there is any need to go to 3". You will want to use some type of metal flex hose...with my install I picked up some flexible exhaust piping in the correct size from the local auto parts store. Heavy duty, I know, but it made sense at the time.

Something like this:

http://shop.advanceautoparts.com/p/nickson-flex-o-pipe-2-inch-id-540201/5600782-P

Others use the thin wall aluminum vent pipe.

 

[Lake Girl]

You will want a hood/screen on the inlet line just to keep unwanted critters out. Sometimes a kit will just make it easier to collect all the pieces...

 

[womaus]

Absolutely a hood, to keep the big critters out. Bees, hornets, etc like to get into those spaces too. Best to cap it in the fair weather months, even if there is a screen to prevent.

 

[BillX]

Thanks Lake Girl and womaus. A hood is for sure good advice. And maybe OAK is the simplest way to go.

I have been focusing on any possible moisture problems which are not a concern with the exhaust. Cold air coming into a warm environment should create condensation on the metal pipe (not so much with PVC but that is not allowed), so I'm trying to decide how much insulation is needed to fend off moisture within the walls.

 

[railfanron]

1 inch of fiberglass WITH a moisture barrier would be sufficient.
Ron

 

[BillX]

1 inch of fiberglass WITH a moisture barrier would be sufficient.
Ron

Didn't think of it, but I like it. Thanks

 

[Pascal_Maertens]

Hello Everyone:

I'm new to this forum and am looking forward to connecting with other users. I'm confused about one issue. I have a Piazzetta Sabrina stove installed in the basement.

The dealer that installed the unit didn't put either a fresh air vent or an outside air intake. I'm not sure either is necessary but it's not running that well (creating clinkers very easily). I have adjusted the combustion fan to a higher setting on all levels which will require more of a demand for fresh air (as well I reduced the auger feed rate).

I'm thinking of a fresh air pipe, possibly 3" to maximize the flow, which shouldn't be that hard to do. I'm trying to get a hold of a micromanometer as I'm doing all of this blind at the moment.

Any suggestions would be appreciated.

Welcome on the forum, you will find that on a forum you will get as many advise as there are people. Hi everyone ! September... I am back from a nice summer fishing camping and boating. Well well well... I do not want to offend people that are kindly trying to help you, but I'll be the only one saying this to you because ( I do sale and own a Piazzetta ). Most people have north american stove that have no ajustements beside a trap that you can open or close there is nothing more to do than bringing cold air from outside. once you will get that manometer you will find it very easy to set your stove to the correct ( water Colum or pascal ) mention in the tech manual. if in need of help then just send me a message and i'll be more than pleased to help you. Mean will you can go to read this tread I made only for Piazzetta stove; https://www.hearth.com/talk/threads/piazzetta-pellets-stove-a-to-z-recommendations.147362/

Best regards
Pascal Maertens

 

[BillX]

Welcome on the forum, you will find that on a forum you will get as many advise as there are people. Hi everyone ! September... I am back from a nice summer fishing camping and boating. Well well well... I do not want to offend people that are kindly trying to help you, but I'll be the only one saying this to you because ( I do sale and own a Piazzetta ). Most people have north american stove that have no ajustements beside a trap that you can open or close there is nothing more to do than bringing cold air from outside. once you will get that manometer you will find it very easy to set your stove to the correct ( water Colum or pascal ) mention in the tech manual. if in need of help then just send me a message and i'll be more than pleased to help you. Mean will you can go to read this tread I made only for Piazzetta stove; https://www.hearth.com/talk/threads/piazzetta-pellets-stove-a-to-z-recommendations.147362/

Best regards
Pascal Maertens

Thanks Pascal Maertens:

Appreciate the advice and link. Cheers.

 

[searcher]

1 inch of fiberglass WITH a moisture barrier would be sufficient.
Ron

I'm enjoying learning a lot from this forum, hope I'm using it properly. "Womas' replied "...using flexible exhaust pipng from an auto parts store" (as an OAK) - then 'Billx' replied "any possible moisture problems which are not a concern with the exhaust. Cold air coming into a warm environment should create condensation on the metal pipe (not so much with PVC but that is not allowed), so I'm trying to decide how much insulation is needed ...'.then your reply ...

My question now is where/how the 'insulation'? Just in the wall? Around the OAK? I installed without one, so could be a touchy re-fit ...

 

[womaus]

My question now is where/how the 'insulation'? Just in the wall? Around the OAK? I installed without one, so could be a touchy re-fit ...

My reading of the condensation problem is the air inlet (OAK) getting damp between the wall and the stove...due to the cold outside air reacting with the warmer interior temperatures. Just like a glass of ice tea in the summer getting condensation on the outside of the glass.

In my configuration I've only got about 3" of air inlet tubing exposed in the interior of the house (maybe not even that much). I've not seen any issue with water dripping off of it, nor have I noticed even slight condensation. It could be that that area never gets really warm...we don't excessively heat the house, we use the pellet stove to just take the edge off the interior temps. We keep a cool house.

My configuration also uses the Harman OEM wall thimble, it incorporates the OAK and the exhaust into one unit. Looks like this:

http://tinyurl.com/zzjg3ve

That will link off to a vendor, has 3 or 4 pics of the unit.

So, I've got no insulation on the inlet in the interior of the house, but the wall was stuffed with RockWool where needed when we installed the Harman vent. This house was insulated with blown-in cellulose many many years ago.

I'll see if I can get some pics tomorrow and update this post.

 

[BillX]

I'm enjoying learning a lot from this forum, hope I'm using it properly. "Womas' replied "...using flexible exhaust pipng from an auto parts store" (as an OAK) - then 'Billx' replied "any possible moisture problems which are not a concern with the exhaust. Cold air coming into a warm environment should create condensation on the metal pipe (not so much with PVC but that is not allowed), so I'm trying to decide how much insulation is needed ...'.then your reply ...

My question now is where/how the 'insulation'? Just in the wall? Around the OAK? I installed without one, so could be a touchy re-fit ...

I did put some thin insulation around the 2" pipe where it sits inside the wall. There is no need beyond that.

My experience is the same as womaus - no condensation on the bare piping inside the room. Mine is in the basement where it's cooler and that could be the reason, not enough temperature difference to cause moisture. If you are getting no moisture on the incoming pipe inside the room, I don't see why there would be any concern inside the wall

If you plan on adding some insulation, it should not be difficult to pull the piping and wrap it. Of course you would have to increase the hole diameter for the larger pipe.

 

[Lake Girl]

The only time my OAK frosts up really bad is when we hit the steady sub-zero weather. No frost at -4C/25F today.

 

[OhioBurner©]

I have several feet (~12' maybe) of flexible duct, and a good chunk of the time the stove isn't even in use so it all acts like a big heatsink with cold air inside going across my living room. I wrapped it with that foil backed pipe insulation wrap from Lowes, then to make it look nice I wrapped it with plastic from pellet bags that somewhat matched my carpet color.



I wrapped the insulation up to about the last 6" behind the stove, but I stopped the plastic about 2' away from the stove.

 

[Mt Bob]

Lots of good info,as usual,and womaus always a wealth of info,thanks.And thanks to Pascal,he is great with tose stoves.As far as the condensation,usually not a problem out here,until it is below -15f.People in higher humidity places may have bigger problems.I use a "dual" vent,similar to the harman,but made for a smaller opening,and can actually build ice on it inside the house when the stove is running in a high mode.You do not want to insulate the oak pipe all the way up to the stove,let the inside house air heat and expand the air before it reaches the combustion chamber,is more efficient.I put a valve on my intake,just inside the wall(3" woodworking dust collector valve,as my harman has a 3" intake)and switch it to use inside air when I see moisture or frost.Yes,I may loose some heat,but do not have to clean up moisture off floor.