Lessons from living with my "water system"
"how NOT to do it"
If you have read through this blog, you will see that a large portion of it was devoted to "water". You will also see that I had a lot of "bright ideas" and plans.
I have now had some time to actually live with it. Some things worked well, others not so well, others turned out downright ugly. About the only part of the system I have not been disappointed with is the tank and tank filling system. My only desire there is to come up with some other location for the tank. It takes up quite a bit of room in such a small space. What I will likely do is somehow integrate the filters with the tank by either mounting them on top or around the tank.
Issue 1
The fist big issue I had with the system, was the pump. It was a 2 gallon/minute 12 volt diaphragm pump. This was necessary for the pressure it can reach to be able to push water through the "reverse osmosis" filter. I had it turned down to produce 70 PSI through the filters.
Pump failure (AKA Use an expansion tank at the pump outlet!)
The pump I had chosen lasted about 4 months. The biggest reason for this is that I did not put an expansion tank at the outlet of the pump. What this meant was that the pump was constantly cycling on and off as the water flowed through the RO system. It also pulsated on the output side very badly. In the end it was simply too hard on the pump and it burnt out prematurely.
Another issue in regards to the expansion tank is with the water heater. I did not install the tankless water heater in here. Instead I had bought a motorhome to use while I was gone for work and installed it there. In this way I am able to give a review of the performance of that.
First off, the motorhome also used a pump of about the same type and capacity. What I found is when I was on "pump water" (without an expansion tank), the water heater would constantly cycle on and off. It was unusable. The reason for this was the intense fluctuation of water flow and pressure from the pump.
When water was sourced from the camground, the water heater worked as well as, if not better, than expected. It was perfectly acceptable for everything from doing dishes to showering. I would HIGHLY recommend it for a container or cabin as far as the water heater itself! I am hoping to get another one in the near future and try it as a source of heat for a hydronic heating ("hot water") system for the entire "box".
Solving all problems
I believe that if I had added an expansion tank at the pump outlet, this would have solved all my problems. The expansion tank would very much dampen the output from the pump. What this means in this situation is that the pump would have lasted much longer (as it would have run less and more smoothly and had a more consistent pressure at the outlet) and the water heater could be used on pumped water (because of the lack of fluctuation in pressure and volume). In summary, I cannot stress enough the need of an expansion tank at the outlet of the pump!
Have a backup pump (and plan) ready!
Here I am speaking of the need for at least a hand pump. For a while I reverted back to the 5 gallon water container with a hand pump. This I had from before I put the tank in. As I tried to decide my next move, I still needed drinking water. With the 5 gallon water container (the type used on a water cooler), I at least could refill it from a clean water source for drinking water.
The picture is representative of what I am talking about. These are available on ebay quite cheap. They also snap on to the top of the jug.
Until I get a final solution to the whole setup, I have set the hand tank and pump aside and simply installed this pump inline with the filters
This is a $6.99 "Harbor Freight Special". All I can say "good" about it is that "its a pump". It has some slight leakage at the pump shaft and it produces very little pressure. It is also easy to "blow the hoses out" if too much pressure is applied. Because of this, I am currently only operating on the normal filters and the UV light "disinfector". I had to remove the RO filter from the system as this would not produce nearly enough pressure to push water through that filter. Basically, right now, the main water system is only good for a clean drink of water :-(
Where do we go from here?
Well, four big modifications I plan to make to the system.
- Somehow combine the tank, pump and filter system to save space. This will also have the added advantage of making the entire system "portable".
- Add an expansion tank at the outlet of the pump or pumps so the pump does not have to work so hard.
- Add a hand pump inline with the electric pump for backup. Right now the whole thing is simply "rigged" together to get drinking water. If I have a hand pump permanently installed on the inlet side of the electric pump, I will not have to make any modifications to the system if the electric pump should fail (you can "push" or "pull" water through a diaphragm pump without modification).
- Add valves to bypass the RO filter when using a hand pump. As it is now, I had to physically change the tubing to bypass the RO filter for use with the hand pump. A couple valves and some tubing would be better so I can simply change the valve settings and flow water around it if using the hand pump.
Well thats the summary of where the water system stands. I hope somebody can learn from my mistakes!
