Bruce, We routinely cut off DWV as suggested by earlier posts so that they are at least 1 inch below the surface of the back of the module.
To be clear these are sewage intake air vents and not exhaust vents for heating appliances. We do place a quarter inch wire cloth over the cut off vent and apply a four inch stainless steel hose clamp around the pipe just to prevent foreign objects from entering the vent pipe. I have never had an inspector question this method. With Regards Carl Adams, President SunRock Solar 513.290.9072 (cell) 513.766.6025 (office) On Sep 24, 2014, at 1:37 PM, Ray Walters <r...@solarray.com> wrote: I agree with Kurt: you need a licensed plumber in your area to advise you, if you're trying to keep the AHJs happy . 2nd, I'm very sure you don't want an exhaust/ combustion type vent under the array. I've had several over the years, and seen some arrays installed over them. They can get fairly hot and put quite a bit of steam out. I would not trust the module backing material to a concentrated long term dose; which module is going to have a problem first? R.Ray Walters CTO, Solarray, Inc Nabcep Certified PV Installer, Licensed Master Electrician Solar Design Engineer 303 505-8760 On 9/24/2014 11:16 AM, Kurt Johnsen wrote: > Should you decide to lower your plumbing vents I have found an inside pipe > cutter to be an inexpensive and handy tool. Cut the vent and lead off an inch > above your desired pipe height and use the inside cutter to cut the pvc pipe. > Go slow and be careful to keep air space between the pvc and lead as the lead > will cut very easily. > > > > Also I wouldn't rely on us well intentioned wrenches to make the call on the > plumbing code in your jurisdiction. Though the state plumbing codes are > usually based on the international code, there will be differences. If you > can't pull up your state plumbing code online then ask your plumbing > inspector. In Florida the minimum height above a roof surface is 6" (904.1). > As for relocating 905.2 states that “all vent and branch vent pipes shall be > so graded and connected as to drain back to the drainage pipe by gravity”. > Table 710.1(1) shows that for 1.5” pipe a slope of ¼” per foot is sufficient > to handle 3 fixtures. I would take that to indicate ¼” / foot is plenty for a > 1.5” vent. > > >> On Wed, Sep 24, 2014 at 11:20 AM, Dave Click <davecl...@fsec.ucf.edu> wrote: >> Flipping through the '04 plumbing code I see a few slopes called out (1/4" >> per 1' for fixture vents, 1" per 1' for circuit vents, 1/2" per 1' for >> combination drain/vent...). Fixture vents have a maximum distance of a few >> feet from fixture trap to vent, but I don't think this prevents you from >> then running that vent horizontally. 916.2 states that for vents other than >> stack vents or vent stacks if your vent is >40' you need to upsize the whole >> vent pipe (tough to do for an existing building, of course). Stack vents >> have a "maximum developed length" of 100' for a 1.5" vent which should be >> enough space to get away from under the PV. I don't see any slope >> requirements specifically for stack vents but my non-plumber's eye may be >> missing something. >> >> The stack vent sizing Table 916.1 appears (in part) here too and it looks >> like the tables match up to a 2.5": >> http://www.engineeringtoolbox.com/drainage-vents-d_1110.html >> >> DKC >> >> >> >> >> On 2014/9/24 10:19, Jason Szumlanski wrote: >>> I am unable to find anything in the Florida code that precludes covering a >>> plumbing vent. The code does require the vent to be 6" above the roof >>> surface I believe. >>> >>> I was unable to determine if these vents need to be vertical with no bends >>> in the attic. Obviously you wouldn't want to create a trap in the attic, >>> but a couple of 45's to relocate a plumbing vent to accommodate more PV >>> seems like a desirable thing to do sometimes. Does anyone know if these can >>> be relocated, i.e. to an adjacent roof surface? >>> >>> On my own home I had a vent to deal with. I broke out my saws-all, split >>> the lead like a banana and peeled it back, cut the pipe at an angle, and >>> folded the lead back into the pipe after applying sealant between the lead >>> and pipe. There is a 1" gap between the rim of the pipe and the back of the >>> module. My theory on this working safely is that, >>> a) there will be far less rainwater falling in and around this pipe with a >>> module over it, and b) it is about 24" from the roof ridge and there is a >>> module over it so there will be very little water sheeting >>> down from above the vent. Code notwithstanding, I felt this was a >>> solid method on my own home, and I have inspected >>> it after 6 months of Florida downpours and found no issues. >>> >>> >>> Jason Szumlanski >>> Fafco Solar >>> >>> >>> On Wed, Sep 24, 2014 at 6:38 AM, Bill Loesch <solar1onl...@charter.net> >>> wrote: >>>> >>>> Bruce, August, et al, >>>> >>>> This is but one more example of confusing terminology. A plumbing vent is >>>> not an exhaust vent! >>>> >>>> A plumbing vent (what August calls a cold vent) is provided to allow the >>>> sanitary drain traps (and perhaps more) to operate properly. Without the >>>> properly functioning traps you would have sewer gas smell and sewer gas >>>> from the plumbing fixtures. This was commonplace when indoor plumbing was >>>> introduced to early adopters. >>>> >>>> An exhaust vent is another animal entirely. An exhaust vent carries the >>>> combustion products to a suitable exterior location for dilution with >>>> ambient air. With the advent of power vented combustion appliances, a >>>> direct vent (one that takes in combustion air from the outside and >>>> naturally exhausts combustion products to the outside) is IMHO the only >>>> responsible way to install any power vented appliance in a freezing >>>> climate. (Power vented appliances come in both condensing and >>>> non-condensing flavors-they can penetrate the side wall or the roof). >>>> Originally, two separate pipes (with two independent properly separated >>>> penetrations) was used. That technique is still often used today. More >>>> recently concentric vents have been introduced both for condensing and >>>> non-condensing applications. A concentric vent can simplify some >>>> installations by putting the exhaust pipe inside a larger air intake pipe >>>> allowing for one, albeit larger, penetration. As you might imagine if the >>>> exhaust flow is hindered/diverted/redirected by an inappropriately located >>>> solar module combustion gasses will be re-ingested into the intake air. >>>> Not good for equipment performance. My understanding is the power vented >>>> appliance manufacturer dictates what kind of separation/clearances are >>>> needed with their product. My guess is you find they want at least a foot >>>> of separation between the top of the " inverted cone" and the module. >>>> Probably not what you had in mind for an aesthetically pleasing >>>> installation. >>>> >>>> I hope this helps, >>>> Bill Loesch >>>> Solar 1 - Saint Louis Solar >>>> 314 631 1094 >>>> On 23-Sep-14 6:54 PM, August Goers >>>> wrote: >>>>> Bruce and All, >>>>> >>>>> Sorry, I hit send before I had a chance to complete my thoughts. What I >>>>> meant to say was that I've found AHJs often allow us to cover cold >>>>> plumbing vents but I've never tried or had any luck with covering hot >>>>> vents including condensing boiler PVC vents. Once again, if in doubt you >>>>> could see what the plan checker or inspector thinks. >>>>> >>>>> Best, >>>>> >>>>> August >>>>> >>>>> -----Original Message----- >>>>> From: August Goers [mailto:aug...@luminalt.com] >>>>> Sent: Tuesday, September 23, 2014 4:15 PM >>>>> To: 'RE-wrenches' >>>>> Subject: RE: [RE-wrenches] Modules over vents >>>>> >>>>> Bruce, >>>>> >>>>> I'll send you the CA plumbing code vent section offlist (attachment too >>>>> large for this list). The way I read the code is that you technically >>>>> can't cover any type of plumbing or hot vent. However, and I've run into >>>>> little resistance from AHJs in the Bay Area by covering these. You might >>>>> want to check in with your plan checker. >>>>> >>>>> Best, >>>>> >>>>> August >>>>> >>>>> Luminalt >>>>> >>>>> -----Original Message----- >>>>> From: RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] On >>>>> Behalf Of Bruce Leininger >>>>> Sent: Tuesday, September 23, 2014 3:49 PM >>>>> To: RE-wrenches >>>>> Subject: [RE-wrenches] Modules over vents >>>>> >>>>> Hi all. We're designing a system on a roof that is literally infested >>>>> with plumbing, exhaust and combustion vents. The combustion vents are PVC >>>>> and none of the vents are more than 1.5' above the roof. >>>>> >>>>> A racking company says that we can cover them with modules, since the >>>>> modules will be at least 4' above the roof. They have not yet provided >>>>> any building code references to say that this is ok. Do any of you know >>>>> if the building code allows this? >>>>> >>>>> Thanks. >>>>> >>>>> Bruce >>> >>> >>> >>> _______________________________________________ >>> List sponsored by Redwood Alliance >>> >>> List Address: RE-wrenches@lists.re-wrenches.org >>> >>> Change listserver email address & settings: >>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >>> >>> List-Archive: >>> http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html >>> >>> List rules & etiquette: >>> www.re-wrenches.org/etiquette.htm >>> >>> Check out or update participant bios: >>> www.members.re-wrenches.org >> >> >> _______________________________________________ >> List sponsored by Redwood Alliance >> >> List Address: RE-wrenches@lists.re-wrenches.org >> >> Change listserver email address & settings: >> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >> >> List-Archive: >> http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html >> >> List rules & etiquette: >> www.re-wrenches.org/etiquette.htm >> >> Check out or update participant bios: >> www.members.re-wrenches.org > > > > _______________________________________________ > List sponsored by Redwood Alliance > > List Address: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > www.members.re-wrenches.org > _______________________________________________ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
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