Vito and CPVC

Mitch_4

What happened up here is that the national gas code (our beloved B149) has always had a requirement for special venting systems. FOr Cat IV it had to meet CSA standard 636. For years manufacturers have tested and certified high eff equipement wit BS, PVC, CPVC as prefered, and no one made an issue. (I have installed units 25 years old with ABS..sealed and tight still!! (I service I did not install)

It was never a problem until power vented water heaters. They are not condensing but use high air volumes to cool the flue gases. Problem is that they are usually in laundry rooms and poorly maintained. So the wheels got plugged, and the ABS / PVC/ CPVC melted, caused an uproar, the the AHJ's decided, hey maybe we should enforce the code, and so we now have to use S636 venting systems everywhere. It has been law in all provinces since Sept 07. Currently until manufacturers can provide S636 specialty pieces for inside unit cabinets for some manufacturers and the Bazooka concentrics are exempt until July 1 2008. as (gee big suprise here ) no one looked at the ramifications. Inside teh appliance cabinet is not part of teh B149, it is part of the furnace certification..but S636 says you can't mix pipe...and no one bothered to talk to the concentric termination people either..

THere is a whole cluster (****) involved in this that I need not go into here, but suffice it to say..it was NOT well thought out

Metro Man

Vito and CPVC

Talked with the Vito boys other day and will be changing a 200 around from concentric to 2-pipe CPVC. (Don't ask why it's a long story). My thoughts would be that the next step would be to go SCH 40 ( we can on the intake) but evidently there has been some issues with glue breaking down from the chemical concentration of the exhaust with the condensate and in Canada there has been some failures. So Vito says no way hose - ay to solid core 40.

So........ why are the Vito's more worried than anyone else. How many installs of mod/cons, high-eff furn, and etc.. are there out there using approved solid core schedule 40? Does the condensate coming out of a Viessman have more "hootspa" than anyone elses??? if so we should save it for some industrial purpose.

To me venting is usually the most pain in the dupa (but the most important) and since using PVC piping has made installing more of a breeze... plus the guys get to play with glue.

Has anyone changed or installed with CPVC on a Vito and what issues if any have you found?

Gratt-see in advance.



Metro Man

marc

CPVC

Be carefull, the only CPVC approved by Viessmann is only sold by Viessmann (in US market) Normal schedule 40 CPVC is NOT approved!!! Viessmann is the first manufacturer that I am aware of taking a stand on the PVC venting. Maybe try 3" SS venting for the exhaust and pvc for the intake. I would think that the SS is less money than the approved CPVC!

Good Luck, Marc

Metro Man

See PVC

Here is info I was give by the ViessMAN

CPVC Vent System:

1. CPVP vent material must be ULC/UL listed for category IV boilers "suggested" source: IPEX inc

2. talk of supporting vent

3. Combustion air may be made of the following materials: ABS, CPVC, PVC, or stainless steel.

I realize that ya can't use pvc 40 for they're exhaust.... just wondering if anyone had done this type of venting with CPVC and PVC. Not sure on the $$ comparison between SS and CPVC will check with my local guy in morning. Also not sure we ever had ULC/UL listed CPVC in stock b4.

My big questions still is why the Vissman hold out to using what everyone else in the industry has been using. They are certainly not the hottest firing mod/con..... (168*F max I think) do they know something we don't or just extra careful, or ????

What I am hearing from them as a concern is not to mix your CPVC brands.


Metro Man

tom_49

I have installed a vito 100 w/ cpvc bought from Viessmann ( ipex ).They also have the primer and glue.Thats what they spec., so thats what I did.

Be careful pricing the job, you might want to check the price of the cpvc before quoting.

The stuff goes together nice.

I think pvc venting has been banned in Ohcanada. What are they using now?

Ed_26

pvc venting

O'canada gas vents (cat. IV) will require S636 certified PVC pipe & Fittings (w/approved glue/primer)IPEX is certified, others to follow. Most provinces by June/08?

Metro Man

venting my gas

Tom,

Did you use the double pipe adaptor and sch 40 for intake? I like the idea of using plastic since being able to cut to exact size is critical on this project. Will find out more today on $$ for the cpvc.

Still wish these guys would approve #40!

Thanks

Metro Man

Paul Sohler

Other manufacturers who prohibit PVC venting

Viessmann is not the only condensing boiler manufacturer that prohibits the use of PVC venting. Crown has never permitted its use on any of our condensing boilers. Instead, we allow the use of two basic types of venting:

1) A concentric PPs (polypropylene) vent system. A basic "through-the-wall" kit of this type is included with most of our wall hung models. Components for longer runs and/or vertical systems are available through our distributors.

2) Alternatively, all of our condensing boilers may be vented using one of the four generally available AL29-4c stainless steel vent systems.

There is at least one additional condensing boiler manufacturer that does not permit the use of PVC venting.

Paul Sohler
Crown Boiler Company

Metro Man

TO PVC OR NOT TO PVC

So why then the discrepancy (at least in the states) between manufacturers and gov. agencies? Surely a tested type of pvc, cpvc, and it's glue and primer counterparts has XXX temp and press threshold.

There surely is enough installations out there, furnaces and boilers alike, to make the determination once and for all what should or shouldn't be allowed. I'm trying to think when 1st pvc was allowed as a venting material? Would think this practice started on furnaces first at least 15 - 20 years ago????

Just doesn't make sense that what one manufacture approves for his boiler that fires at the same temp, puts out the same amount of condensate is not approved for the next.

Oh well... I guess when I grow up and become a manufacturer I will dictate what is allowed since I am the one standing behind the warranty.

Metro Man

Mitch_4

how long

The first generation of furnaces was around 1982...so 26 years

Metro Man

old

Your making me feel old.. Wonder about any failure issues from those installs?. I do remember a pvc exhaust (can't remember name right now) that had some issues. It was a black, thin walled pvc material that turned brittle when it went bad. Heatmaker used this for a while for they're inner exhaust vent for they're concentric vent.

But back to my point...... if solid core schedule 40 can't take the heat, condensate, and etc.. of these modern day furnaces and boilers (many if not all that are firing cooler than ever) then why hasn't there been a mass recall/code change for using this material?

Inquiring minds need to know...

Metro Man

Mitch_4

Metro man

The original Olsen high efficiency gas units were vented with ABS (solid) 2".(I mention Olsen because I work where they were made)( and I still use them, because they're good), there are litterally THOUSANDS of these things here,and not one has had a vent problem.

The thin wall stuff was designed for mid efficiecny units.

I personaly in 15 years never seen a piece of condensing equipment vented with ABS, PVC or CPVC have the venting fail if installed propoerly. Water heaters? too often becuase they are not condensing, but again the problems show up in poor maintenance.

Metro Man

Plastic Fantastic

I agree Mitch. It's all in how it's installed and maintained. I've also (26 + years) seen my share of conventional venting installed or sized wrong. Usually it's a water heater install that is the culprit. Gotta love the metal tape over seams that didn't quite go together snug enough.

There are enough of these units (mod/con boilers and furnaces) installed that we can look at past data. Just wish that there could be a standardization of PVC across the board that states ... any boiler with X limit flue temp and X amount of pressure schedule 40 is allowed..... period.

Oh well gotta B___ch about something. We'll just use boilers that are approved for the venting that we prefer to use.

Metro Man

marc

PVC

I have looked on standard PVC and cannot find the listing/approval for venting????? Funny how the SS, and coaxial venting is "listed" for its intended purpose! Viessmann and a few other's are finally stepping up to the plate and requiring "listed" venting!!!
Marc

Metro Man

Funny

But Marc if you look at what the manufacturers specs for venting their boilers they specifically spell out what is "listed" as approved vent. PVC Sch 40 - ANSI/ASTM D1785, PVC-DWV-ANSI/ASTM D2665, and others are approved by MANY boiler and furnaces alike. I find it hard to believe that this vent would be approved by so many if there was a problem.

When a job is inspected the FIRST thing the inspector usually looks at is the venting to make sure we're using the right stuff.

So with a 26 + year track record for pvc vent material I would think if there were failures in the field this stuff would've been nixed a long time ago.


Metro Man

marc

Viessmann's explanation

Here is some good reading on why Viessmann wont allow standard sch. 40 PVC or ABS for venting.

Marc

Metro Man

Viessman vent

Thanks Marc. Have printed and stuck into Viessman binder.

After reading I wondered if boiler manufacturers could leave an adjustment for the installer as to what temp to allow flue gasses to reach... within parameters of course. Seems like we can adjust everything else.

You could set your limits based on SS, CPVC, PVC.

Metro Man

scrook_2

PPS?

PPS generally is short for polyphenylene sulfide, not polypropylene (PP for short)! Perhaps an error in translation?

PPS should make a very good exhaust vent material though.

Mr. Robinson's advise, in 1967, to Benjamin Braddock was dead on: "Plastics!"