There has been some previous discussion about this but has anyone actually seen it work.
To save space, we want to have a 'back to wall loo' with a concealed cistern and we want to conceal it in the loft, about 2.5 metres above the loo. Worse than that, we want to run the flush pipe out from the loft though the exterior 8" brick wall, down the outside of the house, and back in through the wall again at the required position for the loo.
Are we being ridiculous?
Robert
if the loft insulation is on the loft floor then will the cistern freeze? and will the outside pipe freeze?
[g]
Modern siphons have the overflow via the siphon and down the flush pipe into the bowl. If overflowing this could freeze up. So not a good idea.
Having the cistern in the loft is a good idea. Use an electric flush button. The pipe can be smaller than normal as the head of water will be enough to push the water down. Also less water can be in the cistern too. A normal sized pipe may result in the water splashing when flushed. Many people when going from a siphon to a flap valve experience splashing in a low level toilet.
A 1" flush pipe may all you need - which can go in the wall. If high enough even a 22mm pipe may do, only using bends. I would do a test on that first before any firm fitting.
Only in the winter. It should work fine in the summer. ;-)
I don't know. Certainly a 2.5m head of water should do an efficient job of flushing the toilet, and I'd certainly be interested to know whether it does it down the drain or in an exciting indoor tsunami. It could be quite a feature.
Daniele
Good luck - I never did see the point of having a tank of water taking up space in the bathroom
The biggest problem is trying to get a decent velocity of water when you flush the loo. Several needless bends are going to severely restrict the flow of water.
Why should that be the case? The tank can be directly above and only bends used. In fact the tank can be in the apex to give a great head, and only
22mm plastic pipe used. If too head too great put an in-line restrictor in.
This is almost exactly as you describe:
A few points:
o As others have pointed out, freezing is most definitely an issue. However, for all we know, the 'outside' wall could be within a conservatory or something else that would protect it. o This, as many other BTW WCs, has an outflow at the back - which also has to go through the wall. I think you might find it difficult to find a really compact one that has a side or bottom outlet that would work within the room. o Make sure that there is room for the seat to fit properly - i.e. not fall down.
That link is to the Blue Book which contains extensive details of the company's WC (and other) products. Most useful are the detailed installation diagrams.
In fact we want the outlet and inlet to both go through the wall so the choice of WC is quite large.
It's an intersting thought that 22mm pipe might do it, but if we want bends (not elbows) then it cannot really be embedded in the wall.
Freezing: we'd build the loft insulation over the cistern so it would be inside the bathroom from a heat point of view. Freezing in the external pipe is more difficult to stop, and the overflow problem makes this more important. A fros tstat and heater seems a bit excessive.
With all that torrent of water, perhaps I could make a new design that washes the cleint's bum at the same time as flushing the loo:-) Most invigorating.
Rhere's my calculation of the required tube diameter.
normal system: 42mm diam, 0.5m long, 1kg/sec (all guesses)
using
We need the same flow rate and pressure at the loo:
new 2.5m long, 1kg/sec, pressure at loo 4120 (same), head =3D
25,000pa so the pipe pressure drop is (25000-4120)/2.5 =3D 8,352 Pa/mFor 1kg/s the table gives a pipe diameter of.... er... 22mm (as someone more experienced above guessed).
Interesting.
R
A bit :-)
Ive got a close coupled in a space only about 2'6 deep.
Biggest problem will be throttling the flow, and freezing of pipes outside.
The head on even a trad 'up near the ceiling cistern' loo is enough to flick turds out of the pan..
I was thinking of doing the same in my ensuite but in the end decided not to.
A concealed cistern doesnt take up much room. They are tiny. It has to be fitted within a very limited range of heights above the pan. Def not in the roofspace
Assuming you dont want a pull cord flush then you want a push button flush on the the end of a pipe - which is what comes with a concealed cistern and not with much (anything?) else so far as I could discover
So I gave up on the idea ...
And it turns out that in a tiny bathoom the shelf above the boxed in cistern is EXTREMELY USEFUL
Anna
Thats the main q, the necessary tube dia for it to work as before. I'd try a test rig-up on which it was easy to replace the tube with a diff dia - eg try it in the garden first.
Overflow is easily handled, just add a standard header tank style overflow in the loft. This will act as a secondary overflow.
That leaves the freezing pipe q - and I can see that being a problem. Each flush, if cold enough, may leave a thin film of water in the pipe that freezes. Plastic has more chance of behaving better than copper, and I guess you could always retrofit insulation if it proves necessary. If the situation is such that you could always run an internal flush pipe later if you had to, then go for it. If not, I'd think its unlikely to block with an insulated flush pipe.
Go for it. You could take some piccies and put it on the wiki.
NT
We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember The Natural Philosopher saying something like:
Damn! I hadn't thought of that for my Victorian cast-iron jobby.
That brings back memories of a campsite near Istanbul in the late
1960's - no toilet paper supplied ! Whoa ! what does one do? Only to discover a well polished little tap just at hand which did supplied just as the OP describes.Rob
My sister's house had originally that sort of head (cistern in loft), but the pot was probably designed for high level flushing.
Having seen some replacement HL bogs with new pans, the tsunami is a likely possibility. Thinner pipe may control this.
Don't cast iron jobbys damage the pan?
G.Harman
A work colleague did this with his old cast-iron bell cistern, with the pull cord coming through the ceiling. The head of water and the resulting powerful flush could shift the most immovable logs from the pan and blasted it clean as well, apparently. I never had an opportunity to test drive it.
In fact, the first IA (immediate action) drill on a partially blocked (not overflowing) toilet is a large bucket of water poured in as fast as possible; the second IA is a large bucket of water poured in as fast as possible whilst standing on a chair (once the level has dropped). It has never failed me.
My modern close-coupled 6 litre water-saving BS toilet often fails to clear the pan of even small deposits and then requires several additional water-wasting flushes.
The only problem I anticipate is splashing, but you should close the lid on any WC before flushing; the range achieved by the water droplets is quite impressive. You may well find that it works effectively with a reduced water content.
If the cistern is within the insulated envelope of the building, it will be no more liable to freeze than a cistern in the bathroom.
In message , Onetap writes
I think it should be fine as long as you didn't make the mistake of flushing whilst still occupying the throne in question, the resulting pressure differential could pull even the strongest person down the pan too...
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