Vent Pipe - Size Matter?

[Reddog2]

I am having my old worn out VC wood burning insert with a new Jotul C550 insert that requires a 6" vent pipe connection. The existing pipe that is run from my roof to the top of my box is a 8" pipe. Can I just connect the new stove to the top of the box with a 6" flex pipe (approximately 2.5') or does the whole 25'+ pipe up to the roof need to be replaced with a 6". Are these things engineered to obtain the proper draft with a 6" pipe the entire way or is this considered a minimum pipe size. Thanks in advance.

 

[bholler]

What type of fireplace is the insert in with what type of chimney?

 

[webby3650]

We have connected a few non-cat inserts to an existing 8” liner. We always let the customer know that it’s not ideal and could pose a problem with draft. If so, they’d be responsible for the cost of adding a 6” liner. We’ve never went back to those installs because of an issue with the liner.

 

[bholler]

We have connected a few non-cat inserts to an existing 8” liner. We always let the customer know that it’s not ideal and could pose a problem with draft. If so, they’d be responsible for the cost of adding a 6” liner. We’ve never went back to those installs because of an issue with the liner.

Yes we do the same and I would recommend that here. But the wording of the post makes me think it may be installed in a zero clearance unit using the original chimney

 

[webby3650]

Yes we do the same and I would recommend that here. But the wording of the post makes me think it may be installed in a zero clearance unit using the original chimney

Hopefully not

 

[Reddog2]

What type of fireplace is the insert in with what type of chimney?

I added a couple pictures of the box. Not sure the fireplace/chimney type? Thanks.

So far, it sounds like it may be a waste of money to replace the whole thing. Doesn't make much sense to me how a larger size pipe would reduce your draft.

 

[bholler]

I added a couple pictures of the box. Not sure the fireplace/chimney type? Thanks.

So far, it sounds like it may be a waste of money to replace the whole thing.

That is some sort of zero clearance box. I know Vermont casting made one to put their insert in at one point I suspect that is what you have. Regardless you need to find out exactly what you have before moving forward. I suspect you cannot use the jotul in that box

 

[Reddog2]

That is some sort of zero clearance box. I know Vermont casting made one to put their insert in at one point I suspect that is what you have. Regardless you need to find out exactly what you have before moving forward. I suspect you cannot use the jotul in that box

Its definitely a VC box intended for a VC insert. Not sure why a new box would be needed for Jotul.

 

[bholler]

Its definitely a VC box intended for a VC insert. Not sure why a new box would be needed for Jotul.

Because that was designed and tested only to work with the vc insert. You cannot use it for anything else.

 

[Reddog2]

So now I have this nice new Jotul 550 waiting to be installed. Where can I purchase a listed UL 127 box that is required for this install? The install should not be that difficult since there is a bedroom behind the fireplace that if the drywall is torn out should give enough access to do all the work. This would eliminate the need to replace all the rock on the front side of the hearth. Who would be able to do this work correctly? The local fireplace guys do not seem to be interested in this work. Is this something a builder would have to take care of? Thanks for the help.

 

[bholler]

So now I have this nice new Jotul 550 waiting to be installed. Where can I purchase a listed UL 127 box that is required for this install? The install should not be that difficult since there is a bedroom behind the fireplace that if the drywall is torn out should give enough access to do all the work. This would eliminate the need to replace all the rock on the front side of the hearth. Who would be able to do this work correctly? The local fireplace guys do not seem to be interested in this work. Is this something a builder would have to take care of? Thanks for the help.

You need to find a prefab fireplace that allows inserts to be installed in them. You will then need to replace everything you have in place including the chimney then run a liner through that new chimney to your insert. If you can return the insert it may be cheaper and easer to just install a high efficiency fireplace. Chances are the opening in the stone will need to change regardless.

 

[begreen]

Would a rear-vented freestanding stove vented into a 6" liner be an option here?

 

[kennyp2339]

@Reddog2 - Lets just eliminate the confusion that maybe present here, this can also be helpful with other that have zero clearance units prefab units.

So your setup is exactly that.. a zero clearance unit, it is a prefab fireplace that is made specifically to be installed next to wood frame construction. The outer jacket which is the box your taking pics of currently can only have a VC winter warm installed within, the outer jacket was tested to hold that. Chances are the existing 8" chimney pipe is not rated for at the standard class A (2100 deg f) for solid fuel burning, they do make a air vented chimney for these zero clearance applications (lighter weight material since the application is designed for 24/7 burning)
All fireplace inserts are built and tested to be installed within a certified masonry fireplace (that's why there's no specific info with installs on most models, it more less is assumed by the manufacture that the application will be in masonry with the proper clearances)
In the zero clearance fire place world, there are only a very few hand full on manufacturers that are willing to have masonry inserts tested, certified and installed within there zero clearance unit.
Testing is rather time consuming, costs money, and honestly.. some zero clearance manufactures don't even have an insert line so they don't want to test to send business to another company.
Retrofitting an approved zero clearance fireplace to an approved wood insert includes no modifying any existing venting / jacket material, insuring that the chimney is rated to class a standards (incase of chimney fire)
Your existing unit is already missing the actual wood burning fire box, if anything the new insert would have to be installed within the fire box, not in the outside jacket which is pictured.

 

[bholler]

@Reddog2 - Lets just eliminate the confusion that maybe present here, this can also be helpful with other that have zero clearance units prefab units.

So your setup is exactly that.. a zero clearance unit, it is a prefab fireplace that is made specifically to be installed next to wood frame construction. The outer jacket which is the box your taking pics of currently can only have a VC winter warm installed within, the outer jacket was tested to hold that. Chances are the existing 8" chimney pipe is not rated for at the standard class A (2100 deg f) for solid fuel burning, they do make a air vented chimney for these zero clearance applications (lighter weight material since the application is designed for 24/7 burning)
All fireplace inserts are built and tested to be installed within a certified masonry fireplace (that's why there's no specific info with installs on most models, it more less is assumed by the manufacture that the application will be in masonry with the proper clearances)
In the zero clearance fire place world, there are only a very few hand full on manufacturers that are willing to have masonry inserts tested, certified and installed within there zero clearance unit.
Testing is rather time consuming, costs money, and honestly.. some zero clearance manufactures don't even have an insert line so they don't want to test to send business to another company.
Retrofitting an approved zero clearance fireplace to an approved wood insert includes no modifying any existing venting / jacket material, insuring that the chimney is rated to class a standards (incase of chimney fire)
Your existing unit is already missing the actual wood burning fire box, if anything the new insert would have to be installed within the fire box, not in the outside jacket which is pictured.

This case is a little different the box we see was made and tested to house the Vermont castings insert that was in it. So it is meant for use with an insert. Just not the jotul he wants to use.

 

[Reddog2]

The old winter warm did have a metal jacket around the casting. There is one piece that I am still confused about. The installation instructions for the new Jotul includes info for installing the insert into a listed prefabricated zero-clearance fireplace. There is a picture of that vendor manual in my post above. It also specifies the fireplace must be listed per UL 127. All of the nameplates on the old make "outer jacket" it really clear that the outer jacket is only intended for the VC Winterwarm model 1280. The namplates also have no markings for UL 127.

I assumed we would be able to purchase a UL 127 box like the one shown in the manual and be stuck with tearing out the wall, modifying some stone work and new chimney liner. (do-able) Now I am hearing that that is not possible and I am stuck with a $3000+ boat anchor in my family room. I don't even want to know what the cost would be to install a masonry fireplace up 2 1/2" stories right in the middle of my house. I'm sure the floor (above crawlspace) would not even be able to handle that weight.

Wish I found this site a long time ago..

Thanks for the help.

 

[begreen]

Replacing the current fireplace with a new one, just for an insert would be an expensive folly. Speak with the dealer and see if you can exchange for a rear-vented freestanding stove.

 

[bholler]

The old winter warm did have a metal jacket around the casting. There is one piece that I am still confused about. The installation instructions for the new Jotul includes info for installing the insert into a listed prefabricated zero-clearance fireplace. There is a picture of that vendor manual in my post above. It also specifies the fireplace must be listed per UL 127. All of the nameplates on the old make "outer jacket" it really clear that the outer jacket is only intended for the VC Winterwarm model 1280. The namplates also have no markings for UL 127.

I assumed we would be able to purchase a UL 127 box like the one shown in the manual and be stuck with tearing out the wall, modifying some stone work and new chimney liner. (do-able) Now I am hearing that that is not possible and I am stuck with a $3000+ boat anchor in my family room. I don't even want to know what the cost would be to install a masonry fireplace up 2 1/2" stories right in the middle of my house. I'm sure the floor (above crawlspace) would not even be able to handle that weight.

Wish I found this site a long time ago..

Thanks for the help.

There are ul 127 fireplaces that do allow inserts to be installed in them but most do not. I believe many new heatilators do. And there are a few others. You would tear out the existing box and chimney replace with a new chimney and fireplace then drop a new liner. That all seems like allot of work and money to go through when what you really want is a high efficiency fireplace.

 

[begreen]

Yes, there are good EPA fireplaces on the market that will match or exceed the C550 performance.

 

[Reddog2]

Yes, there are good EPA fireplaces on the market that will match or exceed the C550 performance.

Can you give me a few options? Is a "Napoleon High Country 3000 Eco" what your are referring to as a EPA? My home is 2750 square feet, very open concept with the fireplace in the center.

The stand alone wood burning stove is not really a option with the boss at home. Thanks.

 

[bholler]

Can you give me a few options? Is a "Napoleon High Country 3000 Eco" what your are referring to as a EPA? My home is 2750 square feet, very open concept with the fireplace in the center.

The stand alone wood burning stove is not really a option with the boss at home. Thanks.

Yes that is a high efficiency or EPA certified zero clearance fireplace. They are basically Woodstoves made to be built into the wall. There are many option from many different manufacturers.

 

[begreen]

RSF makes several EPA ZC fireplaces. There are also EPA fireplaces by Kozy, Astria, Pacific Energy, Valcourt/Osburn, Heatilator, Travis, etc..

 

[webby3650]

Chances are the existing 8" chimney pipe is not rated for at the standard class A (2100 deg f) for solid fuel burning,

This particular system uses a class A insulated double wall chimney. An oval heavy wall flex attached the insert to the chimney.

While the cabinet was only approved for a VC piece of crap, it has huge clearances around the insert and the box is insulated. The chances of the Jotul ever having a problem are almost none existent. But..., no one can say it’s ok, because it’s never been tested so it’s not approved. There’s a lot of folks stuck in this situation.

 

[Reddog2]

Thanks for the help. We have decided to go with the Osburn Stratford unit due to the limited size of the existing opening. It is a little small based on the square footage of my home, but hopefully it will lower my electric costs in the winter. I have another question related to the installation of this unit. The operation/installation manual calls for additional hot air outlet connections on the top and forced air distribution connections on the back/side. If these are used, will the unit actually put out more heat? I have a very open house design with the fireplace located in the center. There are no zone concerns. Just want to make sure I am getting max output.

 

[begreen]

The forced or gravity air distribution kits are optional. One would use them to move heat to another location closed off from the fireplace. They do not affect output. I suspect the Osburn will equal or exceed the old VC's heat output and long as fully seasoned wood is burned.

 

[Reddog2]

Thanks. See attached picture. I wonder if the combustible mantel distance rule would still apply if I route all the heat from the two 8" connections on top of the Osburn to those 2 existing outlets above the mantel? I really do not want to replace or move the oak mantel. Especially if the old vs new fireplace put out the same amount of heat...