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CPVC / PVC - boilers

Steve_210
Steve_210 Member Posts: 647
in THE MAIN WALL
I am installing a Buderus 162/80. I have a letter from Buderus saying that PVC is legal for vent and exhaust - except for when you are using glyco in the boiler. The NYC code states, boiler must be installed as per manufacturers instructions. I know they only changed from CPVC to PVC sometime last year. I am just wondering if anyone has installed one of these boilers in NYC and has had any problems. Because I have almost 60ft of a vertical run it will be impossible to change after the fact and I am a little concerned.

Thanks

Comments

  • Brad White
    Brad White Member Posts: 2,399
    Plastic Venting

    The issues I have always had with plastic venting are:



    1) Chlorides leaching and running back into the combustion process. (Buderus recognizes this given their trap detail after the vent leaves the boiler.) Some say this is less of a problem but with aluminum boilers especially, I have my reservations.



    2) Temperature. What happens when the boiler fires making DHW and what temperatures do the flue gasses reach vs. the temperature rating of the plastic pipe? Especially PVC which is lower than the others such as PP and CPVC, as I recall. Also if the boiler has a run-away incident and runs to limit, can you access all of the venting to inspect and replace it?



    3) Penetration of fire separations. When penetrating a shaft or fire separation, sure it is smoke-stopped and sleeved, but the material itself is essentially combustible. It would have to be wrapped in Fyre-Wrap or other rated enclosure unless it is in a dedicated shaftway to atmosphere.



    The above may or may not be issues in practice, but our office specifies only AL29-4C for Category IV appliances. An exception would be short runs with systems such as Viessmann Vitodens which is engineered and listed for the appliance. I am sure that there are exceptions, but the above is my take anyway. Open to learning more always.



    My $0.02

    Brad
    "If you do not know the answer, say, "I do not know the answer", and you will be correct!"



    -Ernie White, my Dad
  • CMadatMe
    CMadatMe Member Posts: 3,086
    Venting PVC

    Here's the skinny. PVC Mfgs have told all boiler and furnace mfgs that PVC is not a vent material and they own the responsibility. You can vent ULC-S636 vent material which is rated to accept flue gas temps to 210 degrees. I found this company www.centrotherm.us.com that makes a single wall vent material that is ULC and is comparatively priced. They are also in Albany.



    PVC is only rated to 149 degrees so when installed in a vent system in certain applications flue gas temperatures exceed its rating substantially. If there is an indirect on the system exceeding the rating is a definite. Generally for a mod/con your flue gas temps are in the area of 15-20 degrees higher than your return water temperature.



    I would love to see the boiler and furnace mfgs testing that gives them the ability to sleep at night knowing they are giving the green light to vent with a material that the company that makes it says it's not a vent material. All the lawsuits that I know of that are going on right now in conjunction with carbon monoxide have one common thread in all of them.  Every person from the installer to the boiler mfg are named the lawsuits except for the PVC mfg. Pretty weird that a pipe that's rating can't handle flue gas temps above 149 is not named in any suit. Lawyers generally name everyone in a suit.

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  • Steve Ebels_3
    Steve Ebels_3 Member Posts: 1,291
    Noticed today

    The Viessmann concentric vent we were installing on a vitodens is rated to 120*C or about 250*F.

    That's quite a stretch from the rating for PVC.



    I think that in the near future (within 5 years) we are going to see some changes from furnace and boiler manufacturers. I would guess that the only thing holding the majority of them back right now is that if they recommend discontinuing use of PVC venting they open themselves up to having to replace millions of PVC vents already in service. GULP!!
  • Steve_210
    Steve_210 Member Posts: 647
    thanks

    i decided to go with cpvc for the exaust. I would love to know if anyone has had any actual proublems with pvc though as alot of condensing boilers now allow it on both exaust and vent. 
  • CMadatMe
    CMadatMe Member Posts: 3,086
    Seen Many

    PVC vent systems with yesllowish discoloration which is a sign that the PVC is breaking down,, sagging due to higher flue gas temps than the temp rating, fittings pulling away due to expansion and contraction.

    If your going to use CPVC suggest you use one that is rated ULC-S636 which means it was tested and is a vent pipe for removing flue gas. There is only one manufacturer currently in North American that has this rating and that is I-Pex and it's not cheap.



    The alternative is to use the material from my previous post. It is rated ULC-S636, has a 10 yr warranty and is reasonable priced. Much less than the ULC-S636 CPVC. Another nice selling feature of this product is that you have a vent system that is warrantied!

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  • Steve_210
    Steve_210 Member Posts: 647
    ta

    thanks again
  • Nick Ciasullo
    Nick Ciasullo Member Posts: 44
    My Understanding

    is that PVC was outlawed in Canada for use as boiler venting, and it wasn't "Grandfathered" in.  If you have it in your house, you have to get it removed.  I was told it was failing and there was risk of exhaust into the home.
  • CMadatMe
    CMadatMe Member Posts: 3,086
    Cost

    I truly believe that PVC venting was born because manufacturers needed a way to keep the venting price down to allow them to selll their high efficiency product. Ask Buderus, Viessmann, AVC (triangle) and any other European mfg if they vent PVC across the pond and why the don't? They know its not a safe practice to vent PVC. They have been doing condensing boilers a heck of alot longer than us so why do they not vent PVC?

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  • rich pickering
    rich pickering Member Posts: 277
    not here.

    It's grandfathered in Sask.
  • Steve_210
    Steve_210 Member Posts: 647
    PICS

    anybody actually seen it fail better yet any pictures
  • CMadatMe
    CMadatMe Member Posts: 3,086
    I've Found The Answer

    Don't use it... I had my second meeting today with CentroTherm..It is approved by just about everyone boiler mfg. The only boiler manufacture that hasn't step to the plate is Burnham. Sorry guys but it's true.



    It is also approved for venting Noritz Condensing On Demands. Finally, the opportunity to sell a vent system that carries a 10 yr warranty...Which would you rather sell.. PVC which has none or a system that is not much more (can't discuss pricing) but does.



    I know the pro's here will! www.centrotherm.us.com

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  • pipe4zen
    pipe4zen Member Posts: 108
    What about Furnances?

    Anyone know what temps high efficiency furnances run at that are vented with PVC?





    1) If PVC fire penetrations are an issue because of the PVC material, would'nt the same hold true for PVC used for DWV plumbing within. PVC has ASTM E 84 fire ratings.



    2) I have not seen any AL HX fail from chlorides yet, can't say the same about stainless steel HX, seen a failure 2 year old, causes by chorine.



    3) Is'nt there a correlation between pressure and temperature and PVC ratings. (Like PEX)

    EX: Max 160*F @ 260 psi sch 40

    So as long as the exhaust has an open end (hopefully to the great outdoors) and is in a non pressure situation PVC meets and exceeds the needs of a high efficiency furnance or boiler as a venting material. But if want to sleep better at night, use schedule 80.



    Attached specs for one PVC manufacturer in case anyone needs to show inspector.



    http://www.charlottepipe.com/Documents/PL_Tech_Man/Charlotte_Plastics_Tech_Manual.pdf
  • HDE_2
    HDE_2 Member Posts: 140
    Misinformation

    Both Burnham models, the Alpine and Freedom allow PVC/CPVC
  • Techman
    Techman Member Posts: 2,144
    Venting

    The Burnhan manual states"All CPVC vent components [ supplied with boiler ] must be used for near- boiler piping before transitioning to Schedule 40 PVC pipe components for remainder of vent system " and " CPVC vent components must be used within any interior space where air cannot circulate freely , such as air inside a stud wall , and in any boiler closet " and "When using the CPVC/PVC vent options ,the use of CPVC is required when venting in vertical or horizontal chase ways "
  • CMadatMe
    CMadatMe Member Posts: 3,086
    edited October 2010
    I don't see any Misinformation

    In any of the posts. The question is.  What testing data  does Burnham have that rates PVC or even CPVC as a vent pipe? Absolutely none. Call them up and ask them. Tell them you have a customer that wants to see the testing data before they decided on their install.  



    CPVC is still only rated to 190 degrees. Only I-Pex ULC-S636  CPVC has a rating of 230 degrees and is stamped as a vent pipe. ULC-S636 is a Canadian standard and not a US Standard.



    The problem with getting a plastic pipe rated by UL comes from the PlexVent days. One of the test that is required is that the pipe can handle 430 degrees. Not going to happen with plastic. I know of a plastics manufacturer that has passed every test to get their vent pipe UL rated and they are working on getting a clarification on this required test as it's product it directed toward the condensing boiler market where we do not see flue gas temps higher than 200 degrees. They want the standard for that final test changed to reflect 230 degrees for condensing boilers. This is a realistic test. Even at that rating PVC will never be rated as a vent pipe. 



    Venting PVC is just a way to make condensing boilers which are already higher priced than conventional boiler some what affordable to consumers. InnoFlue has been approved by pretty much every boiler manufacture for use on their boiler except for Burnham because they can't get anyone from Burnham to return their phone call. It's even approved by Bradford White for venting Power Vented Water Heaters.



    What's more important. The comfort of knowing you just installed a true vent system for your customer that carries a warranty or knowing you just installed a plastic that is not rated for venting. Are the few dollars and I mean few dollars in cost difference really worth it.

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  • Jack
    Jack Member Posts: 1,049
    I have a copy of Charlotte Pipes letter on pvc for venting.

    In the letter they list all the ASTM standards to which pvc is tested and listed. They make a point that no ASTM standards covers pvc as a vent for combustion appliances. This takes up the first page. Pg 2 is the "Conclusion" which says that as there is not enough pvc installed they cannot make a reasonable assessment as to its suitability as a vent system.

    Not sure how they can say that. As a result, of there not being enough installed for them to offer an opinion they go on to say that the manufacturer is best able to speak to the suitability of pvc as a vent system.

    I find this to be an incredible letter which tries to reduce or eliminate their liability while keeping pvc vent system sales. All of this is blood in the water to "The Trial Lawyers Assoc". I'd post the letter but my fax/ scanner is inop right now as the desktop is being moved and is not connected. (i love my ipad)
  • Steve_210
    Steve_210 Member Posts: 647
    question

    whats the highest temp anyone has seen on a condensing boilers flue gases.

    the question to me seems to be . Whats the best material to handle acidic condensate and maxium flue gas temp.
  • CMadatMe
    CMadatMe Member Posts: 3,086
    Sprinter

    Generally your stack temp in a condensing gas boilers will be between 15 and 20 degrees higher than your return water temperature. With that said you have to take into considerations the high limit/stack limits on the boilers. Generally they are 210 degrees.



    That is why the standard for condensing boilers should be 230 degrees. PVC begins to breakdown "melt" at 160 degrees. So a system that has a domestic hot water tank sees that 160 when the boiler fires to its limit. Also while the mass of guys that come here and do heat losses set heating curves the majority of contractors do not. They bang these types of boilers off the 180 degree water temp. Some don't even put them on outdoor reset.



    The big hang up with me is that boiler manufacturers have not shown any testing data nor will they return phone calls or e-mails when you inquire. That to me is concerning. Just because a manufacture says its ok to use a product doesn't mean its ok. They all list other ways of venting but highlight the cheapeast way.Why? To make the boiler affordable to consumers.



    This is one of the many reasons I stick with Viessmann. They do not and will not allow PVC on their boilers. Until someone shows me some testing data I'll stick to making sure I sell a vent pipe that is a vent pipe

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  • Mark Eatherton
    Mark Eatherton Member Posts: 5,858
    Do you carry anything other than Viessmann?

    Curious.



    ME

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  • CMadatMe
    CMadatMe Member Posts: 3,086
    edited October 2010
    Yes and NO

    We have 20 plus branches in four states. My branch NO! It's the only mod/con we sell and we do very very very well with it. I'm originally from New England and started selling Viessman 20 years ao and feel its the best line our there. I've always been a fan of the system approach vs a boiler approach. We are the only stocking Viessmann distributor South of Albany NY into NJ. There are a few other distributors in NJ but they just dabble. Have no clue about the line just try to compete based on price. Which is fine with me. I have the technical support and hydronic support among other programs for true Viessmann guys so trying to compete with me on price is fruitless. One of the weaknesses all other supply houses in the market have is strong hydronic support.

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  • Mark Eatherton
    Mark Eatherton Member Posts: 5,858
    So...

    you've never sold a stick of PVC or ABS for venting an appliance then???



    ME

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  • CMadatMe
    CMadatMe Member Posts: 3,086
    Persoanlly

    I have never sold a piece of PVC to vent a boiler.

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  • Mark Eatherton
    Mark Eatherton Member Posts: 5,858
    Same for ABS???

    If you answer that one as a NO as well, then you are indeed a rare cookie.



    ME

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  • Mark Eatherton
    Mark Eatherton Member Posts: 5,858
    edited October 2010
    Deleted

    ...

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  • CMadatMe
    CMadatMe Member Posts: 3,086
    Knead the Dough

    Cause never have.

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  • pipe4zen
    pipe4zen Member Posts: 108
    edited October 2010
    plastic cabinets

    If manufacturers' wont allow venting with PVC, then mostly they would have to stop building their cabinets and other components out of plastic too, right? And they all do! But wht does 0 clearance really mean any way.



    Convient how some on this post keep mentioning PVC melts at 160 degrees F without giving its correlating psi . Just like pex rated at 180*F but at 80psi, well within the range of using it for hydronic baseboard at that temp at 12-15 psi.



    Bottom line an exhaust system even if it does reach the upper most temperature range won't also reach the pressure rating neccessary for failure.



    Gotta go now my pot of water is boiling, I'm going to to try to melt a pvc elbow in it.
  • CMadatMe
    CMadatMe Member Posts: 3,086
    Sagging

    The issue becomes the sagging of the pipe which in turn will allow for the formation of puddles of water in the vent system. Pressure is irrelevant. Don't need any pressure to soften the plastic from heat.

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  • Mark Eatherton
    Mark Eatherton Member Posts: 5,858
    Toss the rocks and pass the hat...

    I guess that fact alone gives you the right to throw rocks at the people like myself that have installed boilers with plastic venting. Just make certain that you tell all of your other bretheren in your other branches to duck when the flack starts flying. :-)



    FWIW, I have a LOT of these boilers out there, and have had for the last 13 years, and can not document one failure of the plastic pipe or fittings.



    Personally, I think you are making a lot to do for nothing, based on the potential of being able to make more money on your newest discovery. And there is nothing wrong with anyone making money. It's just the way that you are pressing the issue that causes the hair on the back of my neck to stand up. You are the ONLY person I know of that has been dealing with modcons that HASN'T used PVC of ABS in the venting of the appliance. Period.



    Obviously, the plastic pipe manufacturers are running scared, and covering their collective butts JUST IN CASE, and I can't blame them for that. But if they were really business savvy, they would get their tubing to comply to the requirements (which it obviously does work based on field experience) and be able to charge more for the product and reap more profit than selling drain pipes...



    As for the boiler manufacturers, trust me, they have a bevy of full time lawyers that have looked at the potentials of this issue, and if they felt that their collective butts weren't covered, they wouldn't have allowed it to take place. These are some very smart folks we're talking about here.



    For example, the I&O manual for the new Lochinvar WBN 51 boiler I am installing REQUIRES 1" clearance to combustibles for the vent pipe. Why, when every other manufacturer says ZERO clearance is acceptable? Because the lawyers went through the I&O manual with their fine tooth comb, and called that specification out. They even require it for the hydronic piping clearances...



    As we were told when we were attempting to get changes to the code to avoid legionairres disease, "Show me the bodies..."



    I will go and take a photograph of the oldest Muncher I have installed in the field. I have seen it before, in fact posted pictures of it, and the PVC is yellowing, but I suspect it is more of an ultra violet break down as opposed to thermal break down.



    Show me yours and I will show you mine. :-)



    ME

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  • HDE_2
    HDE_2 Member Posts: 140
    edited October 2010
    ULC-S636

    No one here thinks that ULC-S636 PVC pipe and fittings is special right? because its not.

    It is the same Sch 40 PVC, solid core pipe meeting ASTM (Plumbing) standards in the US.

    In the summer of 2006 the CSA B149.1 Natural Gas and Propane Installation Code was amended to require all plastic venting materials to be certified to ULC S636. The code change is effective January 1, 2007. Provincial regulators from across Canada changed the B149.1 Code to make certain that all plastic vent systems are certified to a recognized standard.

    It is still 65 degree C or 149 degree Fahrenheit.

    That required rating label and orange sticker elevated the cost 4X the sister pipe for plumbing made on the same production line and out of the same stock. About the only thing they accomplished was to keep the clueless and cheap contractors from using foam-core or cheap import pipe and fittings, improper glue, ........

    As with the earlier plexvent days, it wasn't really the product but the install, improper fittings, lack of support, improper assembly that caused the failures.

    I can understand a distributor person passionately taking a stand against the use of PVC for venting, when they are attempting to compete with product that doesn't allow it. In the end they are attempting to justify the $300-$900 system cost difference of their product install.

    We have vented furnaces, boilers and water heaters for 20 + years that way, (boilers being shorter) it will be a battle boiler manufacturers that have fought but have adapted and changed to in order to gain product acceptance and market share. You can argue that the European market doesn't use PVC venting, yet they also don't use it for plumbing either, so have no easy access.
  • pipe4zen
    pipe4zen Member Posts: 108
    Sagging

    Oh sagging you say.



    Then that really is an issue of poor installation practices and clueless inspectors.

    Follow evey 4ft support hangars, stay away from cellular core pipe, and only use sch 40

    solid pvc pipe.



    PVC pipe manufacturer say there is no ASTM for combustion venting with PVC but follow heating appliance manufacturers guildline.

    Heating appliance manufacturer says use PVC pipe with this ASTM , same as PVC for solid schedule 40 pipe.



    Done, until someone shows me definitive failure on a properly installed venting system.
  • HDE_2
    HDE_2 Member Posts: 140
    I bet

    Chris, the company that you work for sells numerous condensing appliance lines, including boilers that use PVC, so I find that hard to believe.



    What about the HTP Munckin line listed on your  product card?
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,858
    Here's my pictures....

    This installation is one of the first Munchkins I installed in a commercial property over 12 years ago. It is doing ONLY domestic hot water thru an HTP storage tank, which requires 180 degree F water in order to heat the other side of the tank, so it is running as hot as it possibly can.



    I have been watching this vent due to noticing the discoloration the second year in.



    The building is located 100 feet away from the worlds longest commercial street (Colfax Ave) and there is a lot of air pollution in the area. THe white showing in the second photo is because I took my razor knife to the pipe and shaved the exterior off. As suspected, the discoloration is occurring from the outside in, not the other way. I did a visual of the glue joint, and saw nothing of concern at all.



    ME

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  • SpeyFitter
    SpeyFitter Member Posts: 422
    Correction

    IPEX S636 CPVC plastic vent pipe (for the Canadian market) is rated to 90 degrees celsius (which is 194 degrees fahrenheit).

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  • CMadatMe
    CMadatMe Member Posts: 3,086
    Mark

    Would have got back earlier but it's been a hectic Monday.



    I would never question your ethics or installation practices. You as many that come here are ahead of the curve which I think we forget sometimes.  Tradesmen of your caliber account for less than 2 percent of the industry overall. If you feel that your installation practices are safe which I have no doubt they are that is fine with me.



    You like may others take the precautions necessay to make sure that you don't put yourself into a bad situation but to give a green light to every, side jobber, handyman and inexperienced contractor is an issue in my mind. Sometimes I think that those that come here and share forget they are only a microdot of what goes on in the real world.



    I have no agenda to ride a wave. I have been practicing my beliefs and standards to my customers for many years and will stand pat on them until a manufacturer shows me some testing data.  My promotion of a product is to show that there is a cost effective vent product that can be used and that we all should take a look at it.



    I truly feel that PVC is looked at as the cheapiest way to vent. It is not looked at as the best way by our trade in general. I feel it is important to educate the consumer/homeowner so they are given a choice of how they want their appliance vented versus the tradesman choosing it for them.



    If more tradesman took the few minutes to explain that PVC is not rated as a vent pipe but they have an alternative which may cost them a few extra bucks you may see PVC slowly go away. By the trade offering an alternative it also gives them the chance to make a few extra bucks. Instead we are afraid to offer a vent pipe because we may lose a job so we don't even offer it to the consumer. Who are we to make the choice. Our job is to educated our customers and let them make the choice.



    If PVC is so safe for venting then why do boiler manufacturers list it as the "highlight" way to vent but don't state that the ASTM they list has nothing to do with venting? What are they afraid of? The use of listing the ASTM is used as smoke and mirrors that provides false comfort. If they list it they should have to state that it has nothing to do with venting.  They shouldn't be able to ride both sides of the fence.



    They all list AL24C or ULC-S636 but it's always the second and third choices. Shouldn't PVC be the 3rd choice with the statement and the others since they are vent pipes first and second?



    So as long as they promote PVC as the "highlight vent method" with no testing data, I will stand my gound on a vent system that is rated as a vent system and give customers the choice through education based on what information is available.



    It's always a pleasure. Its off to answer al the other replies.. Best Wishes...

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  • SpeyFitter
    SpeyFitter Member Posts: 422
    Lochinvar has some testing data

    Perhaps Paul R can chime in here and correct me if I'm wrong, but I recall at a Lochinvar training seminar here in Vancouver a few weeks ago where we asked about PVC venting of their boilers - we were told that they (Lochinvar) have done some serious tests with PVC where they had a many sensors/probes inserted on a 360 degree pattern around the pipe to test the flue/stack temps of their boilers, even with high water temps, to see how they faired and how the PVC faired. In a nutshell, this was the basis to the guy telling us as long as we used their short CPVC puck piece, we could transition to PVC and run PVC out, even with higher temps. Again, perhaps Paul R from Lochinvar can chime in here and correct me if I'm wrong (this is what I recall your coworker Kevin saying Paul).

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  • CMadatMe
    CMadatMe Member Posts: 3,086
    Has No Bearing

    On my beliefs and what jobs I personally have my hand on. I am proud that I am able to educate my customers to give them the ability to sell a true vent pipe.



    What's funny is that I am the only true stocking Viessmann distributor in my market while everyone else slings the same Triangle, Peerless, Burnham, Buderus etc and I have no problem competing against them with a higher priced boiler with a higher priced vent system.You know why?



    Education and teaching my customers to give their customers the choice. It's not up to us to decided for them it's up to us to provide them with options.

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  • CMadatMe
    CMadatMe Member Posts: 3,086
    ULC-S636

    Rating is for 195 degrees

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  • JimInNJ
    JimInNJ Member Posts: 1
    Vinyl Chloride and PVC exhaust

    An old but interesting and thoughtful thread. Has anything changed in the last couple of years?



    ==> A separate question, PVC is likely to deteriorate in part to it's monomer vinyl chloride.



    My dad was an engineer at BF Goodrich Chemical in Lousiville where it was confirmed the Vinyl Chloride (VC) is a carcinogen for a relatively rare liver cancer and possibly others.



    In these exhaust applications PVC is going to be heated. It seems likely there will be more VC is going to be released. Is anyone concerned about this?
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