need to put the vents in for black & gray first off all sinks and shower have p traps and [spring vents ] not sure what you call
them what i need help with is my bus is a 57 crown round roof i want to put the vent cap in center of roof to do this i would need
to use a hose or pipe that would bend to fit the curve of roof can i use 1'' and can i put a tee to conect the gray & black at the
center of roof to cut one hole and use one vent cover where i want to put it would be 8 to 10 '' behind the a/c unit and 12 to 16 ''
in front of fantaskit vent is this ok ? or what to do thanks ps the tanks are from a monaco dyansty 1 1/2 '' size pipe
i would put in back of the ac and the vent unless you want to smell sewer gasses
I did similar to what you are talking. I installed a T at the center of the roof. I used flexible sump pump hose to connect down both sides, one to the bathroom sink drain stack, and one to the kitchen sink drain line. I'd have issues with smell, partly due to placement of the vent, and partly do to the flexible pipe not sealing properly around the barbed fittings. I placed the T in front of the rearmost roof hatch. When driving, the suction inside pulls air through the hatch seal. I've worked on the seal. I've sealed the connectors of the flex hose with teflon paste and double clamped with offset worm gear clamps. At one point I removed the T and routed the vent to the engine air intake. That sucked the traps dry. No smell while driving, but filled the coach when I'd stop and shut down the engine. I ended up using a combination of the original T roof vent and the engine intake. So far, and a year of travel, and no more smell.
1" is a bit small, but if you ran 2 of them, one up each side, and came directly off the tank, it would be sufficient for 1 1/2" drain lines.
You might find that your traps get sucked dry when you dump the tank.
craig
There is a product called an 'Autovent', that allows air to be drawn in to prevent siphoning, but closes the line with a spring-loaded plate when it is idle. This can be placed just a few inches above the drain level, and will keep the P-traps filled to prevent tank odor from coming back. This product is available in most hardware stores.
On the Crown are your tanks under the bus?
If so why not run the vent under the bus to the back then run up.
:o
i have auto vents on sinks and shower and tanks are in bay under bus right in front of rear wheels
heard if i vent out by wheels you get oders ?
Find a local plumber with a "Heat pad". This can bend ABS or PVC to almost any fit. Some Elec Contractors carry them too. Hope this helps. ;D M&C
Yeah, I tried those under counter vents, too. They leaked sewer gas back inside.
The problem with using those vents, is that if you place them on the sink side of the trap, the trap gets sucked dry and the gases can leak up through the trap and sink drain. If placed on the tank side of the trap where they are supposed to go, then the vent itself leaks gases.
I even tried it with the vent hooked to the engine intake, and not through the roof. The traps still got sucked dry. Not enough air could be pulled through that little vent.
Anyway, it didn't work for me.
Those little vents work fine for me, I have two, one on each sink/shower drain line. They never leak odors, they are designed to only take in air, not let it out.
I also have under bus tank vent, never any odor problems. This vent is 1 1/4" pvc, it needs to be larger when you dump fast, but is ok otherwise. My vent is short, since yours will be much longer you probably need at least 2" pipe.
The only time I ever have odors is when the bus sits and the traps evaporate or when I dump a full tank very fast. Then I just refill the traps and end the problem.
My personal experience is like Gus said; AutoVents will work until the trap evaporates enough to let air/odors pass. Make sure they are placed at a high point between the trap and the tank, and not between the trap and the sink, toilet, or shower.
They are designed to give relief air to the drain pipe and prevent a suction that takes the water from the trap.
They have a very light spring that is easily pulled, by the suction of the water flow, (easier to pull on this spring that to suck the water up from the trap), but that spring is sufficient to close off the pipe when there is no water flowing.
Keeping the trap filled is also important, as it is that water that prevents the odors from visiting with the occupants of the coach.
Crown, I ran all my drains to a common trap. I used 1" and made a trap from that also. I to ran my vent under the bus. I had 1 problem with odor when I tried to see what my top speed was. It must have blown air into my tank, because I could smell it right away. Tom Y
Another one that went UNDER the bus and 5 yrs., no problems what so ever!
My vent is into the rear axle bay by the previous owner, and I plan to change it before starting to use the bus in the spring. The problem is that methane gas, highly explosive, odorless and lighter than air, will be trapped inside the tank and accumulate unless it has a natural, always rising path to vent out of. So, andy vent that doesn't travel in an always rising path, to the outside above anything that could trap it, won't ensure that methane can vent out of your tanks. That's the bottom line, regardless of what other things a vent needs to do.
Run your vents up to the roof. You can do combined wet/dry vents and get rid of all those under counter Air Admittance Valves, and you can tee the black and gray together. But it has to vent to the roof, or it's done wrong. Sorry to be so bold. It's just the science talking...
Brian
thanks for all the imfo i am trying to go up to roof but what about being close to rear of a/c or a roof vent the vent would be used
maybe when showering . as we love a/c . am using 3 a/c but the mid one is more of a back up thats the one that would be close
to tank vent ?
Quote from: crown on February 02, 2010, 12:19:26 PM
thanks for all the imfo i am trying to go up to roof but what about being close to rear of a/c or a roof vent the vent would be used
maybe when showering . as we love a/c . am using 3 a/c but the mid one is more of a back up thats the one that would be close
to tank vent ?
The code says "
Waste holding tank vent openings shall not be less than 3 ft (0.9 m) away from any motor-driven air intake that opens into habitable areas."
If your roof vent is exhaust-only, that's not an "intake." However, an air conditioner may very well be considered an intake if it has provision to bring outside air into the living space.
FWIW, my A/Cs are designed principally to recirculate inside air. For a variety of logistical reasons, one of my three units is very close to the tank vents. I have an air flush toilet, and if that A/C unit is running when the toilet gets flushed, it's a problem, so clearly it does bring a fair amount of air in from outside. We make sure it's shut down when using the bathroom.
If I were doing this over again, I would do whatever it took to get the tank vent at least 3' from the A/C.
HTH,
-Sean
http://OurOdyssey.BlogSpot.com (http://ourodyssey.blogspot.com)
sean does it mater if its rear or front of a/c i need to cut holes in roof looked on e bay for moterhome
roofs looks like there not 3 ft away not saying it corect just looking for all the imfo i can get before
cutting roof posting a picture
Quote from: crown on February 02, 2010, 03:37:02 PM
sean does it mater if its rear or front of a/c i need to cut holes in roof looked on e bay for moterhome
roofs looks like there not 3 ft away not saying it corect just looking for all the imfo i can get before
cutting roof posting a picture
Well, as I implied earlier, whether or not a roof air is considered a "motor-driven air intake" is open to interpretation. Clearly, several RV manufacturers have interpreted that it is not, and I myself presumed that when I designed my coach (based on Dometic Penguin specs and the fact that many factory RVs had roof airs closer than 3' to the vents). I later regretted that interpretation, because enough air is brought in by that unit to be a real problem when I flush the toilet.
Now, I have a bigger issue than most folks because of the air flush (every flush pushes 8-10 liters of air out of the tank through the vent). But still, I think it could be a problem even with conventional toilets.
What I am saying is that you may get away with it under the code, but my advice is to keep the tank vent as far from any roof air as possible anyway, unless you want sewer gas in the rig.
I have very, very few regrets about design issues on my coach, and this is one of them. FWIW.
-Sean
http://OurOdyssey.BlogSpot.com (http://ourodyssey.blogspot.com)
sean what type of tolit do you have i am using a microphor tolit
Geez, Louise!
Whatta bunch'a blarney. This ain't exactly rocket science, now is it? Let's see... holding tank. Hmmm.. air pressure and bad smells. One prevents good operation, the other prevents peaceful domicile.
Solution? A hole, preferably with pipe attached, venting into less pressure. Kill two birds - pressure and stink - with one hole (sorry for the mixed mataphor :)).
Yeah, I know I'm gonna get flamed. Too simplistic, too 'female,' too 'not in keeping with some code' that nobody follows anyway.
To my point: Crown, just run a U- shaped pipe out the top of your holding tank and through your bin (luggage bay) floor. Save yourself tons of time and $$ and frustration. Better yet, use a piece of garden hose and some hose clamps to test it out. Doesn't work, nothing lost... but , guaranteed, it will work.
Nellie Wilson.
Quote from: crown on February 02, 2010, 05:48:23 PM
sean what type of tolit do you have i am using a microphor tolit
We have a Microphor LF-210 air flush model. Our waste tank is too far from the commode for a standard direct-drop unit.
Quote from: Nellie Wilson on February 02, 2010, 07:00:56 PM
... just run a U- shaped pipe out the top of your holding tank and through your bin (luggage bay) floor. Save yourself tons of time and $$ and frustration. Better yet, use a piece of garden hose and some hose clamps to test it out. Doesn't work, nothing lost...
Unless it explodes.
Folks, there's a reason why vents MUST slope upwards at all times and exit through the roof. This is true in houses as well as RV's. Sure, you might get away with it indefinitely and never have a problem. But the next guy might die from it.
I don't want to rehash this whole debate in this thread -- probably everything that can be said about this has already been said on this board already. See this thread:
http://www.busconversions.com/bbs/index.php?topic=12131.0 (http://www.busconversions.com/bbs/index.php?topic=12131.0)
-Sean
http://OurOdyssey.BlogSpot.com (http://ourodyssey.blogspot.com)
While in florida, we went to an rv show in Ft Meyers, I was looking over a brand new TravelSupreme with all the toys, the unit was show priced at a thrifty 500K, down from 650K according to the nice guy that was trying to sell it to me lol, I commented on the quality of the plywood in the drawers and the staples, I remarked that I prefered dovetails, he told me they were dovetail fasteners, I went ohhhhhhhh I see lol. The vent on that one went from the tank in the back bay straight up to the top of the bay, took a 90 to the rear and into the fender well, then took another 90 and exited the fender well with a small scoop that aimed it to the back, I wonder what code that brand new coach was following. That was a couple of years ago.
Sean -
Not for one second do I doubt your wisdom and authority on this matter - and I sincerely mean that.
However, I am parked within 15' of a bus professionally converted in 1991 - by a well reputed converter - that has both fresh water and holding tanks vented through the bottom. Neither the previous owner - a corporation that used the bus as a mobile 'think tank' (sounds rather appropriate ;D) nor the present owner (of some 15 years) has had a problem.
Anecdotal evidence? Yes. Convincing evidence? Also yes.
But buds can disagree, right? Luv ya!
Nellie ;)
My bus was owned by a blues singer before I got it, he had it converted by the Caldwells, they are a very respected professional conversion company, the black water tank had a straight drop out the bottom thru the bottom of the bay floor, controled by an air switch on the dash lol, the vent also went straight down thru the floor, I've been piling sawdust in buses, motorhomes, travel trailers and all sorts of rvs in between for years, I've seen probably every concievable combination of factory venting including a system years ago that fed the contents of the black and grey tank into the exhaust system that supposedly burned them creating a no dump tank lol. I realize the codes are there, I also realize that they tend to have a way of getting around them as the engineering needs dictate at times.
Quote from: Nellie Wilson on February 02, 2010, 09:06:09 PM
However, I am parked within 15' of a bus professionally converted in 1991 - by a well reputed converter - that has both fresh water and holding tanks vented through the the bottom. Neither the previous owner - a corporation that used the bus as a mobile 'think tank' (sounds rather appropriate ;D) nor the present owner (of some 15 years) has had a problem.
Anecdotal evidence? Yes. Convincing evidence? Also yes.
Viviane, I can share many horror stories with you of things I, too, have seen in "professionally converted" coaches and even factory RVs that would give you pause to ever consider buying one. Any home inspector can also share horror stories of unsafe situations they have encountered on the job.
As I have said here many times in the past, just because some otherwise reputable and supposedly professional outfit has done something does not necessarily make it right or safe. In theory, Toyota, as the largest car manufacturer in the world, ought to know how to make a safe gas pedal, too...
As I have also written many times, including in the thread I referenced above, codes exist, in part, to prevent unsafe situations that may occur in a tiny, tiny fraction of cases. So anecdotal evidence that a certain way of doing things has not encountered any problems in some known set of observations is
not convincing -- it's that .0001% when it doesn't work that gets you. As I wrote in that thread, the chance that an airplane will crash is minuscule, and that the passengers would survive a crash smaller still, so why, then, do we equip every passenger with a life vest?
At some level, each of us, perhaps without acknowledging it, is relying on adherence to codes by other people constantly. Would you get on an elevator if you knew that the guys who built it omitted the safety interlocks, or the free-fall brakes? Or would you get on a ship if it had no life boats, water tight compartments, or life jackets? Probably not. Yet you don't crawl into the elevator shaft before every trip to see for yourself if these things were done -- you trust that someone, somewhere, is enforcing compliance to safety standards that you assume exist and have been well thought out to ensure your safety. In fact, when this system of codes and enforcement breaks down, we even tend to be outraged: Why weren't hospitals in Haiti built to earthquake standards? Who let those Colgan Air pilots fly that plane on too little sleep, and blithely chat away in the cockpit instead of watching the instruments, and paying attention to stall speed?
We all understand why cars need brakes, or why people are supposed to stop for red traffic lights, and so we understand (and mostly agree with) laws that dictate those things. Few people understand why bedrooms need arc-fault protectors, water heaters need relief valves, or sewer manhole covers need holes in them. For the most part, this lack of understanding is not an issue because most people do not wire their own houses, build their own water heaters, or run their own sewer systems.
People who convert their own buses, as a matter of course, are taking on a project that will require them to understand (or hire someone who understands) safe practices, and thus relevant codes, in electrical wiring, fresh water plumbing, drain-waste-vent plumbing, ventilation, heating, refrigeration, and, if applicable, gas line plumbing. That's a tall order, and a forum such as this one can be a big help, but it is still fundamentally up to you to learn what you need to know to make a safe conversion.
On the matter of vents, the code is crystal clear and not subject to interpretation -- they must extend through the roof. And the reasons, while less clear to many people, are well-founded and easy to research. I spelled them out extensively in the other thread. Advising people that this provision can be safely ignored based on extremely limited personal observation and other anecdotal evidence, while well-intentioned, ultimately does not square with my perception that you are a person genuinely interested in the well-being of those around you.
Most importantly, I would not want to see you (or anyone else) injured or made ill by an improperly vented system, which is why I also made a firm recommendation about your own vent situation in the refrigerator thread. Hey, you're my bud, right?
-Sean
http://OurOdyssey.BlogSpot.com (http://ourodyssey.blogspot.com)
From someone who bought a previously converted bus, While you are converting it, take the time and effort to put the plumbing vents away from and downstream of your Roof vents and A/C. and also put vents on the drain pipes.
I will say this is my first RV of any kind so it is quite the learning experience. If you're going down the highway at a pretty good clip and the ceiling vent is open even the slightest and someone flushes the potty, there is where you will wish you had put the extra effort into excellent venting :o.
My toilet is the Sealand ball valve type with the strait drop into the tank. I don't know what others have. If the tank were vented thru the bottom of the bus, then the potty would be the highest point, and the inside of the bus, therefore any gas that rises will vent inside the bus. IIRC methane is odorless(gas company adds that smell) and I believe it may rise in air. Either way, any gas rising out of the black tank is not welcome in the bus :o >:(
There many ways to vent and some work somewhat and some is better than none (unless it is venting strait to the bay. :o ;D) but that doesn't make them it a particularly good idea.
If I ever convert or reconvert. I would plan the vents, according to code since we know it. (remember code is a minimum requirement) and I would have two vents on the tanks through the roof most likely and possibly an overflow through the bottom also, for chimney effect flow. Remember air(gas) needs a full path to flow. I do not want the toilet to be a vent again :P >:( :o And I would try to make them away from and behind the roof airs now Sean :D. The pipe drain vent through the roof could possibly work as one of the vents.
Just my opinion from experiencing what not to do. ;)
Since my bus IS converted, what about these spring vent things you speak of?? Any info, pictures?
The AutoVent is available at any hardware store. Usually attaches with a 1 1/4" plastic connector. One such unit is onthis webpage: http://www.plumbingsupply.com/autovent.html (http://www.plumbingsupply.com/autovent.html)
These can save the need to run every line out the roof, BUT, and I hope I never implied this, there MUST be at least one vent line from the drain system to the outside (to get rid of the gas vapors).
If not, the gasses will collect in the pipes, and that could make you think twice about lighting up.
ok lots of stuff to think about i am going up and out roof just not sure where yet i did come
up with a fix for the round roof jaccuzis use flex hose that uses standerd pvc pipe fittings
and glue so that will make the bend easy sean my microphor is almost a direct drop to tank
can you tell me more about them i picked mine up at marathon coach one lucky day they
were cleaning up warehouse and this one had no tank lid bought it for $ 20.00 picked up the
next day and thay found the lid packed away and gave it to me thats all i known about them
thanks
In this case I will agree that Sean is correct in the code and application of it, this code is often varied to a certain extent tho as we have all seen by factories and converters, I will give the floor to Sean in this code tho like I said, however, I have found many times that our resident code expert to be batting approximately 60% in the accuracy of codes and applications of them, this however, is a far better batting average than most of us have, what I'm saying is that it's important for all of us to research the codes ourselves, far too often we take information for granted as being gospel only to find out later that it has been replaced by a new code or adjusted to correct some new found flaw, so don't rely on what you read on the internet, do the research, buy the books and read them.
Quote from: crown on February 03, 2010, 04:56:22 AM
... sean my microphor is almost a direct drop to tank
can you tell me more about them ...
Microphor makes many different models, including macerating toilets for marine use and self-contained models for railroad locomotives.
I have the type that uses compressed air to send the waste to the tank via a 1.5" waste line. It sounds like you have the type that uses a direct drop below a standard flap valve and requires a 3" connection. This type is available in manual or electric flush.
The model number should be on a sticker inside the "tank" area. If it's missing, you might have to go through several manuals to figure out which one you have. But then all the installation and service manuals are available on Microphor's web site:
http://www.microphor.com/html/downloads.html (http://www.microphor.com/html/downloads.html)
Quote from: PCC on February 03, 2010, 04:11:27 AM
[AAVs] can save the need to run every line out the roof, BUT, and I hope I never implied this, there MUST be at least one vent line from the drain system to the outside (to get rid of the gas vapors).
Just to be clear about this, AAVs are permitted as
secondary vents. Each and every drain must still be vented outside. The AAV is used to provide the required anti-siphon air admittance within the maximum 6" distance from the trap. This allows the actual vent to be further away. This type of installation is the only way to implement, for example, an island sink installation.
Quote from: cody on February 03, 2010, 06:05:59 AM
... I will give the floor to Sean in this code tho like I said, however, I have found many times that our resident code expert to be batting approximately 60% in the accuracy of codes and applications of them,
Sheesh, Dan, I've made two or three mistakes in several hundred posts, and you're only giving me a 60?
FWIW, even code inspectors make mistakes -- I've sent more than one back to his code book. These codes are voluminous, no one can possibly memorize all of them, and it's common for us to misremember something that is in one section as being in another. Also, most codes are updated every three years.
This is why I try to look up each and every provision on the spot when I post here.
FWIW, my 1192 is two revs out of date (I have the 2002, and the current version is 2008), and I can't justify buying the latest version just to answer questions here. The mistake I made recently in another thread (http://www.busconversions.com/bbs/index.php?topic=14724.msg157584#msg157584 (http://www.busconversions.com/bbs/index.php?topic=14724.msg157584#msg157584)) was the result of relying on someone else's (bad) information about a change to the code, along with having provisions from the ABYC standards swimming around in my head, which are not relevant here but similar enough to be confusing. (The solenoid we were discussing is mandatory in the ABYC standard, optional in the RV code.)
I did cave in and bought the 2008 NEC when I started teaching coach electric systems (I used the 1999 code when I designed my bus), and so all my posts on electrical systems are based on actual reference to the latest code. And now I've discovered that I have limited access to the 2008 RV code as well. When I find I have made a mistake, I
always go back and correct it.
-Sean
http://OurOdyssey.BlogSpot.com (http://ourodyssey.blogspot.com)
All I'm saying, is that even the most knowlegeable among us can be wrong, don't just take what a person reads on the internet as the final word, hey any sports hero that batted 600% would be fought over by any team, right? lol I even remember once that I thought maybe I had made a mistake in a refinishing article, but I was wrong lol.
thanks one more time sean mine is a microphor L F 220
Check vents, work like a charm, save lots of work, still need to vent tanks. http://www.mobilehomerepair.com/checkvent.html (http://www.mobilehomerepair.com/checkvent.html) Available at the big box stores for a few $$$$
Air Admittance Valves, or "check vents" or whatever you want to call them, are there only to vent a fixture so that it drains properly. They have absolutely nothing to do with venting noxious gases from a storage tank. Totally different application, and they contribute zero to that function.
Anyone who ever lit a fart on fire knows methane is flammable, and if you want to ride around with a tank of it under your floor, that''s your business.
Brian
Quote from: cody on February 03, 2010, 06:48:19 AM
All I'm saying, is that even the most knowlegeable among us can be wrong, don't just take what a person reads on the internet as the final word, ...
This, I agree with completely. I have always recommended to folks here on the board that they actually purchase the latest copies of these publications for themselves. NFPA 1192, the RV code, is available as a PDF download for $37 directly from the National Fire Protection Association:
http://www.nfpa.org/aboutthecodes/AboutTheCodes.asp?DocNum=1192 (http://www.nfpa.org/aboutthecodes/AboutTheCodes.asp?DocNum=1192)
NFPA 70, the National Electrical Code (NEC), is also available as a PDF download, for $85:
http://www.nfpa.org/aboutthecodes/AboutTheCodes.asp?DocNum=70 (http://www.nfpa.org/aboutthecodes/AboutTheCodes.asp?DocNum=70)
The NEC, however, is also usually available in most public libraries. Just make sure you are looking at the latest edition, which is 2008 (the next one comes out in 2011). You may find it's cheaper to just photocopy the pages you need, as the entire NEC is enormous and contains many sections that are not relevant.
The RV code (1192) is not as widely available in libraries, and moreover it is almost entirely germane; well worth the $37 to have your own copy.
Having said all that, I know there are lots of people here who just will not buy these books. So I will continue to write, here and in BCM, about code related issues. Beyond that, some of the code is hard to read, and can benefit from plain English interpretation (yeah, yeah, I know -- some of what I write is hard to read, too). In the course of the eight years or so that I have been on this board, I've probably gone to these codes a couple hundred times just to answer questions from other members.
-Sean
http://OurOdyssey.BlogSpot.com (http://ourodyssey.blogspot.com)
This tank vent thing has been kicked around endlessly.
The fact remains that a bottom vent is no problem and numerous installations have proven this.
I'm still waiting to read about a methane gas explosion caused by a bottom vent!
This vent is as much for taking in fresh air as it is for venting sewer gas. My book on home plumbing doesn't even mention that the vent exhausts sewer gas. When anything goes down the drain it creates a vacumn and the vent takes in air so the traps won't be sucked dry.
There is more hot air about this subject than there is methane!
Quote from: gus on February 03, 2010, 02:09:55 PM
This tank vent thing has been kicked around endlessly.
You mean in this thread:
http://www.busconversions.com/bbs/index.php?topic=12131.0 (http://www.busconversions.com/bbs/index.php?topic=12131.0)
where I took you to task for all the assertions you just made again, even though they are provably wrong and still contravene the law?
Quote
The fact remains that a bottom vent is no problem and numerous installations have proven this.
A bottom vent is
illegal, and numerous installations have simply proven that the problems are
rare. Rare is different from impossible, which is why the code reads the way it does. The fact that millions and millions of buildings have never been hit by lightning does not mean that lightning never hits buildings, which is why building codes require lightning protection.
Quote
This vent is as much for taking in fresh air as it is for venting sewer gas. My book on home plumbing doesn't even mention that the vent exhausts sewer gas.
My book on baking doesn't explain why baking powder makes things rise, either (only that it does). I can assure you that
- Your book on home plumbing DOES tell you to vent through the roof, even if it does not detail all the reasons why.
- The Uniform Plumbing Code (UPC) DOES mention that vents exhaust sewer gas.
As I told you in that thread, I invite you to vent your fixtures directly into your house for a few days, and then tell me that no sewer gas comes out. (Please stay somewhere else, though, during the experiment. I don't want you to get sick.)
As has already been written in this thread -- don't take my word for it. Get the code; it's all there in black and white. And do a little research and you will find that, yes, buildings have exploded from build-up of sewer gases, and many more people have simply gotten ill from them.
-Sean
http://OurOdyssey.BlogSpot.com (http://ourodyssey.blogspot.com)
Quote from: crown on February 03, 2010, 09:44:26 AM
thanks one more time sean mine is a microphor L F 220
The LF-220 is an electrically operated, direct-drop model. Unlike manual toilets from Thetford and others, this model tends to use quite a bit of water; the spec is half gallon per flush.
The amount of water entering the bowl after the flap closes is controlled by a timer. If you use city water pressure (rather than exclusively relying on your internal water pump), you will find a wide variation in pressure and flow rate as you move from site to site, which will vary the amount of water in the bowl. For this reason I strongly recommend you put a pressure regulator on the toilet supply line. We use a compact model made for irrigation systems by Watts.
The manual for this toilet can be found here:
http://www.microphor.com/pdf/LF-220_Manual.pdf (http://www.microphor.com/pdf/LF-220_Manual.pdf)
HTH,
-Sean
http://OurOdyssey.BlogSpot.com (http://ourodyssey.blogspot.com)
I'm pretty sure I didn't say no sewer gas vents through a vent.
I guess I better move my vent, I certainly wouldn't want to have anything that is not exactly according to code.
Quote from: gus on February 03, 2010, 02:53:27 PM
I'm pretty sure I didn't say no sewer gas vents through a vent.
You didn't? I guess I misread this, then (emphasis mine):
Quote from: gus on June 03, 2009, 10:44:37 PM
... Vents in fixed structures are there primarily to prevent a vacumn in the drain system, not to release gas. These vents actually take in air rather than vent it out. Traps keep out the gas.
In fact, you argued this point with me for several more posts. Perhaps you are starting to believe?
Quote
I guess I better move my vent, I certainly wouldn't want to have anything that is not exactly according to code.
As I wrote in the other thread, I would carefully inspect a completed conversion and assess all aspects of the venting system before deciding if an unapproved vent needs to be fixed. As I have already acknowledged, problems are rare, and there are certain to be other issues of more pressing concern.
As I have also written, nothing, and I include my own bus in this, is ever going to be "exactly according to code." But it is irresponsible of you to be handing out advice that flies in the face of the current state of understanding, and dismiss it as "no problem," especially when that advice contravenes the law.
-Sean
http://OurOdyssey.BlogSpot.com (http://ourodyssey.blogspot.com)
This solves the requirements....I think.
Black water tank vent thru the roof. Grey water tank vents thru the roof. Each P trap is followed by a vent through the roof. All my vents are 2 inch. All vents run vertical and the toilet is a straight drop. If you must deviate from this you need to compensate or you are taking your chances. No straight drop....microphor. No vent after P trap....anti siphone valve.
Quote from: JohnEd on February 03, 2010, 05:16:10 PM
Black water tank vent thru the roof. Grey water tank vents thru the roof. Each P trap is followed by a vent through the roof. ... All vents run vertical ...
Just to clarify:
Vents do not need to remain vertical. They only need to continuously slope upwards. Nearly horizontal runs or runs at angles such as 45° are permitted. Vents may also come together into a combined vent stack, as long as certain rules are followed about minimum sizing.
So, no need to make your roof look like Swiss cheese; in a carefully designed system, even one with two separate tanks and three fixtures plus toilet, you can still get by with one single 1.5" vent through the roof.
We chose to use separate vent stacks for black and gray, principally because the air-flush toilet moves a lot of gas out the stack with every flush, and I wanted no possibility that back-pressure at the roof cap could push sewer gas back down the gray stack and out a fixture drain with a partially empty trap seal. So I actually have two 1.5" vents terminating through the roof (just a couple inches apart).
My kitchen sink is over eight linear feet from the vent stack (and tank connection -- it's a wet vent), and around two 90° bends (the sink is right in the middle of the bus, at the end of a counter that separates the galley from the salon), and I had no trouble getting proper slope on both the drain and vent sides of the waste tee all the way to the stack. No AAV needed. FWIW.
-Sean
http://OurOdyssey.BlogSpot.com (http://ourodyssey.blogspot.com)
Sheesh.
Where the heck is that code book when you need it? Guess I'll just steer clear of the Tex-Mex and salsa. Or go find a public flusher. :)
You go, Gus!
Nellie
PS. For the record, my tank is properly vented (per this as yet unveiled code) by a 1.5" pipe, traveling in a continuously upward direction, whereupon it farts straight into the face of the failing ozone layer. (Oopps, that may open a whole new can of methane).
Happily, I have no "motor-driven air intake that opens into habitable areas" - except, occasionally, my dinosaur of an engine - so I needn't be "downwind" of anything, except the blunt (but aerodynamically designed) snout of my bus.
Amazing though, isn't it, how codes and laws and such are always drafted by lobbyists? And championed by folks having a horse in that particular race? So just call me cynical... or maybe I just have a different world view?
For what it's worth, I used spa hose and routed it through the pocket door wall and up to the roof. Seems to work fine, PVC glue to attach on the top and bottom, and real cheap. Here's a link to the work in progress:
http://www.webcove.com/eagle/images/2007-11/04/11wallwvent.htm (http://www.webcove.com/eagle/images/2007-11/04/11wallwvent.htm)
Good luck,
Art
www.webcove.com/eagle (http://www.webcove.com/eagle)
Hey Sunchaser -
That looks pretty nice! Smart place to put it, too.
Wish I'd had my tank before building stuff inside, but things went the other way around... so I had to tear stuff out to run the vent. Much better your way.
Nellie Wilson
thats what i am doing useing spa tubing thanks all i learn a lot hear
Quote from: Sunchaser Art on February 03, 2010, 11:33:10 PM
I used spa hose and routed it through the pocket door wall and up to the roof.
http://www.webcove.com/eagle/images/2007-11/04/11wallwvent.htm (http://www.webcove.com/eagle/images/2007-11/04/11wallwvent.htm)
Clean job !!
Quote from: cody on February 02, 2010, 09:19:40 PM
My bus was owned by a blues singer before I got it, he had it converted by the Caldwells, they are a very respected professional conversion company, the black water tank had a straight drop out the bottom thru the bottom of the bay floor, controled by an air switch on the dash lol, the vent also went straight down thru the floor, I've been piling sawdust in buses, motorhomes, travel trailers and all sorts of rvs in between for years, I've seen probably every concievable combination of factory venting including a system years ago that fed the contents of the black and grey tank into the exhaust system that supposedly burned them creating a no dump tank lol. I realize the codes are there, I also realize that they tend to have a way of getting around them as the engineering needs dictate at times.
Cody,
Builders of entertainer coaches have their own code book, which they keep a top secret.
I have torn into a few of them myself, their theory seems to be that rules only exist to be broken.
I mentioned here a couple of years ago about the tank drains straight out the bottom with no hose connection, and the response was that it was ridiculous, nobody would do that. The driver typically dumped the tanks going down the Interstate at 2:00 A.M.
Generally, the rules are no poo on an entertainer bus, but stuff happens.
Remember the bus that dumped while crossing a bridge, and they paid huge fines in a court decision. That was an entertainer coach.
thanks for arguing all sides guys, it gives the young guys a chance to see every aspect of an issue without having to try them all ;)
If you had read your quote of my statement more carefully you would have noticed that I said fixed structures which is what my plumbing book covers. I also said "primarily", at no place did I say "no or none".
Fixed structure systems are not exactly like RVs, but close.
I've changed my mind, I'm going to leave my bus system just like it is and risk the full wrath of the code police.
I'm also pretty sure I didn't advise anyone else to use a bottom vent. All I remember posting is how mine is rigged and how well it has worked. I stand corrected if you find I said anything differently elsewhere. I think that most bnuts can figure this out for themselves.
I try to avoid advising as much as possible, informing is usually a better way to go. If I do advise I don't become indignant if my advice is not followed.