Saving water

[NFG]

Hi all,

 

I have implemented a simple way to save some water, using rain water to flush a toilet, today we estimated it would save about 120 Euros a year which dosnt sound a lot but its a 'free' 550 in about 5.5 years time - doh!

 

So I thought Id share how I did it & try answer any questions if anyone is thinking of a similar thing.

 

We collect water from the roof into a large 1000 litre butt in which there is fitted a pump - ours runs from 12 V DC but any submersible pump with sufficient lift say 5 or 6m should do, however flow will decrease with height to pump. I only had to lift a couple of metres to go through loft space as toilet on ground floor.

 

My pump had a 1" BSP fitting into 22 mm pipe for a short run connect to a flexible to allow movement then reduced to 16mm.

 

Pipe - I used 16mm (be 15mm in UK) as I had some spare. Larger bore say 22 may not provide better flow as flow would be restricted by inlet fittings on toilet. The pipework was modified with a T junction & an isolation valve & a non return valve on the mains supply to stop cross contamination. Mains water can still be used in summer.

 

Control, this is the tricky bit, I considered several ways & bought a 12V delay off timer (not arrived yet) but the idea is on flushing it will make a momentary contact which runs the pump for a set time - 90 seconds to fill cistern.

 

 

N

[SteveA]

Sounds great. Would be good to see some photos of your setup, if you have any? cheers, steve

[NFG]

Sounds great. Would be good to see some photos of your setup, if you have any? cheers, steve

 

Hi

I was somewhat concerned that may be asked as our bathroom is somewhat rustique...

 

Anyway first pic is the water catchment (the black stuff is from Rape seed oil now cleaned) complete with 12 V supply & bend going to flexible.

 

Next up is the power supply, solar panels feed to regulator & battery, I used a double pole 20 Amp relay (centre left) with 20 A fuse as pump takes 12Amp on 26Amp cable. The black lead hanging down energises the relay when switched & is fused 2Amp on 10Amp cable. Scruffy, but all fused correctly with correct cable diameters etc, its an ongoing experiment.

 

Next some valves on a board quite a bit of soldering and fairly neat - an isolation valve in case I have to drain in cold weather & also a second connection for an accumulator for when we eventully connect the well - its quite a trench to be dug, but will do it eventually.

 

Finally the bathroom, complete with 70's orange tiling 230V socket (we have ELCBs so quite common here) & down pipe all to box in. The pipes here are plastic & the feed from rainwater is on the left - mains water & non return valve - two black blobs after isolation valve on right.

 

All a bit Heath-Robinson at the mo but it works well.

 

Final one is of prettier side of house, just for interest

 

N

Edited February 19, 2014 by NFG

[NFG]

Hi Steve

 

I have now fitted a delay off timer, this means that one push from a momentary switch triggers a 12V relay which changes state, connecting the NO & C contacts to start the pump & commence the countdown timer - so it runs the pump for about 2 minutes which is the time taken to fill the cistern.

 

12Vdc Delay Timer Relay Module - 1 to 180 Second | Quasar CI001

 

N

Edited February 22, 2014 by NFG

[kevinjohnsonmbe]

I think there are issues with building regs in the UK. Something about having separation between mains fresh water and any other system to ensure there's no accidental back-wash of 'unprocessed' water into the mains water system. Not sure of the details but recall discussing it a while back with a guy at work. He had a neighbour running bulk tanks from his green house into his house to save money on his water meter. He got busted because of the risk of Legionella or something...

[SteveA]

Hi Steve

 

I have now fitted a delay off timer, this means that one push from a momentary switch triggers a 12V relay which changes state, connecting the NO & C contacts to start the pump & commence the countdown timer - so it runs the pump for about 2 minutes which is the time taken to fill the cistern.

 

12Vdc Delay Timer Relay Module - 1 to 180 Second | Quasar CI001

 

N

 

Only just found/seen your photos, thanks for posting them

No worries on the quality of your toilet.... Looks posh to me! (I had a bucket n chuck it compost toilet in a shed for a couple of years/ lotsa spiders lurked in there!)

 

Your setup looks pretty complicated. Did you consider raising the rainwater collection tank and having larger diameter pipes feeding into the cistern?....ie, completely gravity fed and without the electrics.

 

Cheers, steve

Edited February 22, 2014 by SteveA

[NFG]

Only just found/seen your photos, thanks for posting them

No worries on the quality of your toilet.... Looks posh to me! (I had a bucket n chuck it compost toilet in a shed for a couple of years/ lotsa spiders lurked in there!)

 

Your setup looks pretty complicated. Did you consider raising the rainwater collection tank and having larger diameter pipes feeding into the cistern?....ie, completely gravity fed and without the electrics.

 

Cheers, steve

 

Hi Steve,

 

oh yes, weve used a bucket also!

 

Yes, did think about raising tank but was going to end up looking daft outside, Its not too complicated although the wiring is a mess it powers a few of other things as well, anyway:

 

The delay off relay we used is

 

12Vdc Delay Timer Relay Module - 1 to 180 Second | Quasar CI001

 

This is connected to a 12V supply, with a normally open push switch that connects across the two trigger connections when pushed, this then changes a set of relay contacts to switch on the pump.

 

So when using the toilet, it gets flushed, pressing the push switch triggers the countdown timer to initiates filling, it cant be over-filled because of the float valve & the pump is OK to run on a 'dead head' which only lasts a couple of seconds.

 

been flushing rainwater for over a week now & works a treat!

 

N

[NFG]

I think there are issues with building regs in the UK. Something about having separation between mains fresh water and any other system to ensure there's no accidental back-wash of 'unprocessed' water into the mains water system. Not sure of the details but recall discussing it a while back with a guy at work. He had a neighbour running bulk tanks from his green house into his house to save money on his water meter. He got busted because of the risk of Legionella or something...

 

Hi,

 

Im not sure on UK regs, but our plumber said this was fine, theres a non return on the domestic supply which is at about 5bars pressure so no chance of back-wash.

 

I suppose you could always remove the flexible & connect separately if considering something similar.

 

N

[Peasgood]

You can get a 12v "on demand" pump for £50. That would fill the cistern and turn itself off.

Just to depress you further, you can get time delay switches for £1 off ebay.

 

Other than that, well done. I am planning a rainwater harvesting system at the moment, all very interesting stuff.

[NFG]

You can get a 12v "on demand" pump for £50. That would fill the cistern and turn itself off.

Just to depress you further, you can get time delay switches for £1 off ebay.

 

Other than that, well done. I am planning a rainwater harvesting system at the moment, all very interesting stuff.

 

Hi

 

The pump was given to me hence free & I looked at E-bay for the timer but none suitable, I try to avoid E-bay anyway as postage to France either not available or daft price.

 

Please post the links to the pump so it assists others who want to try this.

 

Thanks

 

N

Edited February 28, 2014 by NFG