Rainwater system help required

[ericw]

Matt,

You could try a belt driven vacuum pump from a small (Peugeot?) diesel car.

[Much]

Much,try this for low cost pumping bodge;use an  'AC' mechanical lift pump from a car,driven by a cam from your vawt;they will pump to a modest pressure,then idle against the internal spring until the diaphram returns for more pumping;small flow,but over a period of time might be enough?

I presume this is a fuel pump? I know they're diaphragm pumps, but wasn't sure about viability of converting to pure mechanical. On top of that, it'll be very low flow. Well; I guess the water's already filtered, and I can always add more in parallel...
The other option is a screen washer pump - I don't know if they're usually diaphragm or impeller though. Looks like I'm going to become a regular at the scrapyard soon!

The bilge pumps (and a lot of the dedicated rainwater tank pumps) aren't easily self-priming - that's why I'm looking at diaphragm ones; so I can mount it outside the tank with the assurance it'll pull water back and start pumping again should the pipes run dry.

[billi]

Matt

in case you have solid walls in your garrage , i suggest build your own tank and line it with a good rubber liner  and put a lid on..... ( use the side walls of garage)

As for a pump  i perhaps would use the Navitron solar well pump and allways pump during the day and feed the overflow of your header tank back to the main tank that brings O2 into the water as well

But that depends on the size of the header tank and your water usage

Or this one
http://www.shurflo.com/pages/Marine/marine_categories/potable/potable2.html#

or
http://www.gardena.co.uk/catalog/index.cfm?lang=uk

All the best

billi

[Matt300]

All,

At last I have my 1000l container all cleaned out and filling up with water (today anyway), I am ready to order my pump etc, I have been looking at this one:

http://www.machinemart.co.uk/shop/product/details/cpe120-1in-self-priming-water-pump

Together with a pump control unit like this one:

http://www.machinemart.co.uk/shop/product/details/epc1000-electronic-control-unit/path/booster-centrifugal-pumps

The pump will feed a tank in the loft which will then feed the loo's, it will have 2 ball cocks (one for mains and one for the pump), will the ball cock be strong enough to shut the pump off via the controller (I assume so)?.  The ball cock for the mains being 150 above the overflow.

Any other ideas for pumps/controllers welcome.  Has anyone done such a system?

Matt

[Paulh_Boats]

Matt,

That is a very useful controller you have found but it switches off when there is no water flow (empty rainwater tank). To get it working again you must press the reset button...and that might have to be done every few hours depending upon rainfall and water usage.
In our house I can see us forgetting to reset the device, and therefore using more mains water than we need. The device would also have to be mounted in a visible and accessible location.

There is a good rain controller here:
http://www.reuk.co.uk/Rainwater-Toilet-Flush-System.htm

One of its best features is waiting for an hour or so for the rain tank to fill, so that the pump does not oscillate on/off every few minutes when slowly filling during rainfall.

cheers
Paul

[Matt300]

Paul,

Thanks for the link, I have emailed them for further information.  Any advice about the pump?  I really want a mains powered pump which has a long life and can also be used to pump water on demand for watering the garden (not essential but would be great).

Thanks

Matt

[cortina1498]

Hi Matt, I have a 4 year old rainwater system installed. It consists of 3 x 400 gallon tanks - direct link between tank 1 and 2, and a one way valve between tank 2 and tank 3. In tank 1 I have a float switch (a) and in tank 3 I have a 12v submersible pump. In the loft I have a 25gallon header tank which is fitted with a float switch (b). How it works, when the header tank requires water the float switch (b) connects via float switch (a) to a relay which switches on the pump, when the header tank is full float switch (b) switches off the relay to the pump, the water in the pipe then flows back down into tank 3. Floatswitch (a) tells the relay if I have water, the one way valve is to stop cycling of the pump in low water conditions. I have installed a mains water ball valve inlet into the header tank, with an extended rod to the ball so that if there is no rainwater the mains water will turn on, this is positioned 3" above the normal water height. From the header tank I gravity feed my toilet and have a 12 volt pressure switched pump to supply my washing machine and dishwasher. The whole system is 12 volt and run from a 40 watt solar panel, a 110 amp leisure battery.
I hope this is of some use, if you want to know more, just ask
cheers

[Paulh_Boats]

cortina1498,

I remember my Dad's Cortina very well, occasionally we had to rock the car back and forth when the gearbox got stuck in reverse - happy days!

Back on track...can you post a picture or two of your rainwater system? We can all learn a lot from a working system!

thanks
Paul

[Matt300]

Tony,

I was always assuming I would use a 240v pump but if I can get a good 12v pump that will work off a transformer then that would be great.  Any advice from anyone what I should be looking for and how reliable they are.

I went to the website you recommended and therefore I assume the 12v pump can be switched on from their system.

Thanks

Matt

[cortina1498]

Hi Paulh_boats, Sorry no pictures, but it is identical to the one you described in Reuk's site, except with having the one way valve between the pump tank and the  float switch tank I don't have the delay problem.
cheers

[Paulh_Boats]

cortina1498,

No worries, thanks for the info and the header tank solution looks to be the way to go.

All these eco projects have suddenly become a lot more cost effective with shorter payback times due to inevitable price rises. Water companies want to increase prices up to 4% above inflation, so these rainwater schemes are a good investment to hedge the potential price increases.

Since having our water meter fitted our estimated yearly bill is now £240, down from £420. I might be able to save up to £100 with rainwater loo flushing.

Well done for taking the lead and setting an example!

cheers
Paul

[biscuit]

I've been reading this thread with interest...
There's a bewildering array of pumps out there!  My favourites at the moment ( with many thanks to everyone who has contributed) are as follows:
Mains submersible from machinemart.co.uk
or
12v Whale Premium submersible £21 on Ebay
together with electronic control and float sensors from reuk.co.uk

If you're using mains, which I will be to keep costs down, is it more economical to use a mains pump, rather than 12v with a transformer?  Presumably any form of voltage reduction will take a small current at rest.
Anybody care to comment on the pros and cons of submersbles?

[northern installer]

my experience with submersible pumps:(1)very cheap ones can be ok for intermittant use,but if its a bargain,get two,you will need the spare eventually (2)get one with a built in float switch,to avoid dry running (3)dont buy a cheap one that says 'max head 6m' and expect it to pump to 6m! some makers put the maximum head as the height at which it ceases to pump.
Have fun saving money!

[Paulh_Boats]

Most commercial rainwater system use heavy duty stainless steel mains powered pumps. Clearly they are chosen for a long life, minimal service and a good flow of water from a buried tank right up to a loft tank.

Looking forward the whole country will have rainwater schemes one day, to save energy and reduce demand in droughts so we all need top quality pumps that last forever. The boating pumps are only designed for short term pumping, they are noisy, made of plastic and fairly crude so IMHO it would be a false economy to use them, unless of course you have one spare to recycle. Also the efficiency of them might not be so good.

From a physics perspective you need need a fixed amount of energy to pump water 6m to a header tank regardless of the pump, so its the efficiency of the pump that sets the overall power consumption....although a 12V transformer will waste a few extra watts 24/7.

The better quality pumps (£££) at Machine Mart are continuously rated, meaning you can run them 24/7, but the cheaper pumps are not..presumably they can overheat or the bearings are a cheaper, poorer quality. Also the cheaper pumps seem to use more power because its easier to make a more powerful motor than make a more efficient impellor. Also the better pumps will pump solids and are far less likely to jam if debris or grit gets into them (note: add a drainage point at the bottom of the pipe) - marine pumps are designed to be taken apart when they jam.

The commercial rainwater pumps have multiple chambers (impellors) to get a high head from deep inside a well and hence a good flow of water...thats why they are long and thin I think. When you compare the specifications they are much better at pumping vertically than cheaper pumps and probably more efficient.

So all things considered I will look for a good quality mains pump, stainless, continously rated, suited to dirty water and with an adequate flow at 6M and at least a 12M maximum head. If they dont have a float switch, Machine Mart sell them seperatly.


cheers
Paul

[cortina1498]

Hi Paulh_Boats, I too am on a water meter and using rainwater for my toilet, washing machine and dishwasher my quarterly water bill is now just over £19.00, but this will reduce as I have been in contact with Yorkshire water, because they charge me for them getting rid of my surface water. I have had an inspection of my system from Y.W. last week and they have reduced my bill by £39.00 a year. I also plan to plumb in my electric shower, yet more savings !!
I hope this gives people an incentive to fit their own systems, as you say the water boards plan to increase bills by 4% above inflation.
cheers