Cabin Toilet using rain water ?

[nailbndr]

Is there a certain type of toilet to be used for gravity flow only no water pressure?

Is gravity feed from a 30 gallon overhead tank enough pressure for a toilet to flush ?

Also what size supply line is recommended to the toilet ?

[glenn-k]

Most standard toilets (exception-the ones with the pressure tank inside the back) only require water in the back tank to flush.  You could fill them with a bucket out of a fish pond if you wanted.  This would apply to the ones where you can lift the lid and see the water in the tank in the back.  That is the only pressure they have -it works out to appx 1/2 lb at the bottom of the tank-appx 3/4 to 1 lb when the tank is full.  (.4333 lbs per foot of elevation).  The pressure assisted ones use your line pressure to pressurize the tank -maybe 30 to 50 lbs- when you cut her loose things move.  They are supposed to be the best toilets but are much more expensive.  I haven't had one but don't think there is a way to work one of them manually -ie. no water pressure-- I guess you could just pour a bucket in the bowl-- once water is higher than the trap it should flush -though probably somewhat sluggishly without the pressure assist jet in the bottom.

So -yes - gravity feed from a 30 gallon tank overhead has enough pressure to flush a standard toilet.  Don't forget about RV toilets also - some portable toilets have their own hand pump and water supply -although not always the most pleasant things to deal with.

A 1/2 inch line would serve the toilet fine.

[nailbndr]

Thanks Glenn, I just wanted to make sure it would flush ok before I go to all the work. I can invision indoor plumbing already.

[spinnm]

 It's fun to go to Europe where plumbing was an afterthought.

Supply and drain lines outside.  Water holding tanks anywhere they can find a place to give a little pressure.  Nothing standard.

Makes one realize that if it works, it's good.  Spent a great afternoon with the owner of an antique shop somewhere in the north of England.  She was complaining about the water pressure in her Las Vegas hotel shower.  Said it about cut her in half.

[glenn-k]

Ken Kern was an advocate of the squat plate, however I don't believe there are any places it is accepted or desirable here.  It would take a reorganization of my thinking to get me to use one but  it's the in thing in countrys with water shortages.  Some even run pigs under the bathroom to clean things up a bit.

http://www.iees.ch/EcoEng032/EcoEng032_Subuh.html

More info on how they do it in other places with emphasis on home made fixtures and what to do with them.  Note that this is a 23 page pdf with color pictures for those of you who have a slow connection.

http://www.ecosanres.org/PDF%20files/PM%20Report/Chapter%2013%20Some%20special%20constructional%20techniques%20a.pdf

[hunter63]

Check out this site
http://www.motherearthnews.com/do_it_yourself/2003_August_September/Harvest_the_Rain

[Amanda_931]

Why would you want to waste good rainwater on a toilet--when bathing, washing clothes, irrigating the garden are possible, even if you don't want to drink your rainwater?

The RV (marine, airplane, super low-flow) toilets do need some water flow (could be from a bucket) if not pressure.  Hold the lever down to fill just enough to wash whatever out, then open the bottom valve.

I'm thinking about a pair of 30-gallon overhead tanks, one pumped up daily for hot water, to use for a tub if not a shower.

[nailbndr]

The RV style toilet sounds like it would serve and conserve. Do they install the same as a house toilet?

[glenn-k]

I think it would be a DIY project - not recommending them as don't know them but here is a link to one that is on sale.  The page has a link back to their full line of permanent RV toilets.  Note the sale one is $99 - most of the rest seemed to be in the $249 range.  I don't know what it might take to meet code with this if that is an issue.

[Amanda_931]

I know people who've had a plastic RV toilet in their house for 25 years.  Cold water inlet, drain might even be standard connection--or via an adapter--to the sewer.  No big deal.

There's a flap and almost certainly a trap between the bowl and whatever it flows to.  Has to be, blackwater is nasty.

By the way, at least some of the storeboughten composting toilets have had a bad reputation, although lack of maintenance may be most of the problem.  Sawdust, peat moss, etc. really do work well for odor control.

And for the sawdust/mouldering/composting type, there seem to be two thoughts on the value of urine diverting systems.  Joseph Jenkins--the Humanure guy--on one side (don't bother), everybody else on the other (it's essential).

[nailbndr]

Glenn, I don't think the link you mentioned made the trip. Could you send it again please. I have several RV places around my local I think I might drop in one and take a look see.

Amanda, 25 years years sounds like a pretty good track record. We currently have a good outhouse we built and hauled down on a trailer to the property. Works great just a little cool at times.

[glenn-k]

Sorry 'bout that nailbndr.  I'm stupid--

I think I forgot to paste the link in.  Looking at it again there are more fairly cheap ones listed also.

http://www.pplmotorhomes.com/parts/rv-toilets-tanks/aqua-magic-iv.htm