Need help with water pressure

[suburbancowboy]

This last weekend I finished the plumbing for everything in the cabin.  The results are much less than I expected.  The water pressure in everything but the drain line is horrible and I need some suggestions as to what to do.  This will be a short term issue because in the fall I will install a 500 gallon tank that is 100 feet up hill which should solve most of my water pressure issues.



Some background info.  On the second floor is a 50 gallon water tank connected with a 3/4 inch water line.  It stands between 9 and 10 feet above the first floor.  The 3/4 inch water line connects to a 4 way splitter which is 1/2 inch lines. 
1. One line connects to the bath sink.  There is only a trickle of water coming out there.
2. One connects to the shower.  No water comes out here.  I'm not sure if there needs to be a certain amount of water pressure to make it work.  There are little stems with springs on them under the adjustment values.
3.  Toilet low water pressure but it is ok to if the bowl fills up slow.
4.  Kitchen low water pressure here.  It would take an hour to fill up both sides of the sink.
5. Drain by the toilet.  This is used to drain the system in winter.  There is good water pressure here.  I could fill a gallon bucket in 15 seconds or so.

The only thing that I have thought of doing is putting a 12 volt pump connected to a switch to supply better water pressure. 
If I didn't have the pump on would water still flow through the line? 
Should I be getting better pressure than I am? 
Does the shower need high pressure to work?
Any other suggestions?

[CjAl]

most modern shower heads are low flow. they do this by using high pressure and your sure not going to cut it with 3' of head. even 9' is nowhere near enough. take the shower head off and just hook a hose to the pipe to rinse yourself off woth or pump a pump on it.


is the tank vented?

[MountainDon]

0.43 PSI per foot of head of water.    That is without taking friction losses in the pipes and fittings.

Head = vertical difference in height between point of use and top of water level in reservoir/tank.

FYI, Diameter of pipe makes no difference to pressure.

FYI, Large pipe will flow more volume than small pipe but does not affect pressure.



You need much more head or a pump.


The shower head mfg should have specs on required min and max pressures.

[rocking23nf]

How about adding a water pump along the line?

[suburbancowboy]

My current thinking is to add a 12 Volt pump right below the water tank shut off value.  Will water still flow through it even if it is not turned on?  Things are ok now for the toilet so I wouldn't need the pump on all the time.

[alex trent]

Since this is temporary and you want it simple.

I would put a cheap, small sump pump right in the tank. Simple switch and turn it on for the shower. Off when done...a real simple bypass if you even need it.  i do not think you do, as the pump running when water is off and no flow should not hurt it.

This is a $20 pump and an hour to rig it.

[AdironDoc]

Like Alex said, I know many of us here are running very effective setups with 12V RV style pumps by Jabsco, Shurflo, and others. Mountain Don uses a Shurflo, if I recall. My Jabsco was somewhere around $49 on Amazon, installed in 20 minutes between the water barrel and bathroom, and develops up to 55psi. That's nearly the same as hoisting that barrel of yours 130ft in the air. I initially ran mine on two 6 volt golf cart batteries, $69 each at Sam's Club. It won't let water pass if it's not running, but it's quick and simple and as was mentioned, you could always install a bypass valve if need be.

[UK4X4]

pump wise you can always set up a recirculating system against a semi closed valve ie upstream of the valve is a pressurised circuit and down stream the excess returns to the barrel.

means you get a longer pump life as its always got flow