Cheap drinking water pump system.

[alchemysa]

We are renovating the shack and decided to plumb drinking water from the rainwater tank to a spout on the kitchen sink. Previously we have simply carried rainwater inside and run it through a pottery style filter. The rest of the house (bathroom, toilet, kitchen sink etc) is all serviced by a 240v pump from the bore. Its excellent water, but not for drinking. (240v is our standard voltage in Australia by the way.)

So the problem was, How to pump water from the tank to a small spout on the sink? Gravity would only do the job if the tank was at least half full and it would be tediously slow at the best of times anyway. A 'big' 240v pump would do the job but that would be expensive and huge overkill for such a small requirement. (Oddly enough, it seems that they don't make small 240v 'demand' pumps).

The solution seemed to be a cheap 12v pump, but the 'extras' to power a 12v pump can really add up, so before long it works out more expensive than a 240v pump. (By 'extras' I mean a car battery and permanently attached trickle charger or solar charger.)

Then I had a flash. The ideal power source is a 12v 'jump starter'. I got one for $30 'on special' at 'Supercheap Auto'. Its a relatively small one (600 amps), but thats more than enough to power the pump. But more important is that it has a built-in '2 stage smart charger' (i.e. a trickle charger) so I can leave it permanently plugged in. With this setup i'll always have water even during a power failure. The jump starter will be located in a powered shed. I just have to run a bit of 2 strand wire to the pump that will be under the tank about 6 feet away.

I haven't connected it up yet (the shack is 300ks away) but I've got all the bits and tested it here at home and it all looks good.

Heres the cost of the bits in Australia....

12v 4.5 litre per minute demand pump - $30
600 amp jump starter - $30
2 stage undersink water filter kit $90.
15 meters of quality hose $40

(I also have a simple in-line 'strainer' that will pre-filter the water before it goes to the pump.)

Maybe this solution will be of use to other TBN members.


(PS. The life of these jump starters is pretty good if the others I own are anything to go by. The oldest one I have is at least 6 years old and still going fine.)

 

[radioman]

How about a simple 240v dail timers to keep trickle charger being used during sleeping hours?

 

[teg]

Thanks for posting... That's a project in my bucket list to do... We'll be using solar charger and some deep cycle batteries that we have on hand. I have a couple of 12v pumps...

 

[alchemysa]

Thanks for posting... That's a project in my bucket list to do... We'll be using solar charger and some deep cycle batteries that we have on hand. I have a couple of 12v pumps...

Teg, If you've already got the pumps and batteries then you are almost there. But if you have to start from scratch then a 'little' 12v pump system can work out pretty expensive. One thing I discovered while researching is that it appears you need a reasonably large solar panel to actually re-charge a large battery. Those little solar panels that are about $30 that are sold as battery 'maintainers' can stop a battery from draining but they won't recharge a flat or low battery. So you need a pretty large solar panel, but then you also need a 'solar panel charger controller' so you don't cook the batteries. Thats another $30. Like I said, it all adds up.

And by the way, keep those deep cycle batteries charged up while you are waiting. If they are relatively old and go flat, you might never be able to recharge them again. I'm speaking from experience.

(One thing that I perhaps did not make clear in my original post is that the jump starter will be permanently plugged into 240v mains power, and permanently connected to the pump. This was my cheap way of providing enough electrical grunt to the pump. You can't just connect one of these pumps to a 12v wall wart.)

 

[teg]

Wife's in charge of the electrical stuff She's an EE. The solar panel is (guessing) about 55 watts/3.5 amps... pretty good size. We have a "base" camp in the middle of the property with ele./water/sewer. Basically, I'll take the some of the water guts out of the trailer. Will most likely fill a portable tank and top off a reserve in the cabin. Use the pump to transfer and pressure the system.

I do collect rain water but way too many bugs and other stuff to use it... even after filtering it.

 

[Kays Supply]

It is a little late, but do they have condensate pumps down under? We use them here to pump condensate from air conditioners up to the sewer. They are basically the same size as a small boat bilge pump. It would make the system have less parts if it would work. It should be 220v like everything else down under.

 

[alchemysa]

Hello Kays.

The pumps you mention are probably available here. We also have 240v pumps for the things like evaporative air conditioners. (I have one lying around). But they are not demand pumps that switch on automatically when someone opens a tap. And they tend to be high volume but have little pressure.

 

[Pete Judd]

I have had both the Parr and Shureflo pumps on the boat, both with the pressure switches. They work great, but require 12V DC to make them run. Run time is short, except when taking a shower. A small captive air tank is nice to have as well after the pump to smooth out the flow. They can be made cheaply or here is one from shurflo http://www.shurflo.com/files/Educat...1-731_D_24oz.Accumulator Tank 182-100 200.pdf

 

[alchemysa]

I have had both the Parr and Shureflo pumps on the boat, both with the pressure switches. They work great, but require 12V DC to make them run. Run time is short, except when taking a shower. A small captive air tank is nice to have as well after the pump to smooth out the flow. They can be made cheaply or here is one from shurflo http://www.shurflo.com/files/Educat...1-731_D_24oz.Accumulator Tank 182-100 200.pdf

I had a nice shurflo pump, still in the box, but i gave it away recently to the guy who bought my boat. Thats always the way isnt it? The pump sat here for years without being needed!

 

[turnkey4099]

Why not an AC/DC converter and mobil home pump? Does away with he battery problem.

Harry K