How To Plumb Well Water Lines for 2 Homes

[robstaples]

There are many ways that work. You must have a check valve between the pump and the pressure tank. Most pumps have one built in. You can share a pressure tank between two location, but the far location will have all its demand satisfied by the tank when the pump is not running so bigger pipe will improve performance. With pressure tank at both locations, local tank satisfies local short term demand and flow from other tank will balance both to same pressure. 20 minute shower will cause one or two pressure tanks to empty and performace will depend on pipe diameter. If you run pressure tank on at 40 and off at 60 psi, and you want minimum of 25 psi at shower head, decide shower head size .. flow rate....only one at a time ?.... and see pressure drop for various pipe diameters. Water softeners are pressure robbers. Also dual location pressure tanks absorb water hammer. 100 feet of water flowing and the washer or dishwasher solinoid valve closes, you can get pipe rattle or worse as the water stop suddenly.
I have 1" poly pipe and 60 feet between location with pressure tanks at both locations. I recommend sizing pipe for full pump output at either location and no more than 5 psi drop at max flow. My $.02
Just ran example at calc web site. 10 gal per minute is 3+ psi drop for 100 feet of plastic pipe. 1.25" is 1psi drop.
Pressure Drop: Calculation of pressure drops in pipes

 

[turnkey4099]

So I CAN run two separate lines from the well using a "T" valve to split them (one for the guest house and and one for the main house).

SEE ATTACHED DETAIL -

View attachment 477453

So being it's a closed hydraulic system, once I turn on the water in the future main house, the water will flow from the line from the well and then then the guest house line will begin to drain back and cause the controller in the guest house to sense the pressure loss and kick on the well pump.

Is that correct?

So there shouldn't be any problems or issues later if I do it with the above way, correct?

Yes, except the one line does not "drain back", the pressure in it drops but there will be no water flow. But be careful that you have no check valves on the lines after the "T"

 

[turnkey4099]

.

As long as the pressure switch is BEFORE the manifold or T's, the system will work fine regardless of where the water is used.

(think about it ... turning on the kitchen faucet downstairs or filling the tub upstairs makes no difference, the pump still works as it should. The same holds even if the kitchen faucet was in one house and the tub were in another)

.

Ummm...No, it doesn't matter if the switch is before or after the T manifold, it is still a closed system and pressure equalizes among all the branches.

 

[Pettrix]

The only check valves are in the well (at the pump, halfway up the drop pipe and right before the pitless adapter).

Once after the pitless there will be NO check valves. I will have shut off valves in each house but no check valves.

So for me it will be easier to run TWO MAIN lines from the well. One to the guest house (where the controller will be) and one later to the future main house.

 

[Qapla]

Perhaps, to make it a little less confusing, you just need to look at it a little differently - it all seems to be in the "terminology"

You are actually going to run ONE mainline with two branches. At the point you "T" to take one line to each house they become "branches" of the same mainline - even if the "T" is right at the well.

Where is the pressure tank and switch?

Is the well at the garage or do you have to run from the well to the garage?

 

[Pettrix]

Perhaps, to make it a little less confusing, you just need to look at it a little differently - it all seems to be in the "terminology"

You are actually going to run ONE mainline with two branches. At the point you "T" to take one line to each house they become "branches" of the same mainline - even if the "T" is right at the well.

Where is the pressure tank and switch?

Is the well at the garage or do you have to run from the well to the garage?

The pressure tank and switch are in the guest house garage. The well is 100 feet away and an underground water line will run to the guest house garage.

See this diagram:

 

[TemporaryKubotaOwnerMark]

Perhaps, to make it a little less confusing, you just need to look at it a little differently - it all seems to be in the "terminology"

You are actually going to run ONE mainline with two branches. At the point you "T" to take one line to each house they become "branches" of the same mainline - even if the "T" is right at the well.

Bingo.

Stop thinking of two different houses. It's one well supplying a bunch of outlets (sinks, tubs, toilets, faucets). The fact that they are in two different buildings is not really important.

Where is the pressure tank and switch?

And THAT is the all-important question. Decide where you want that, and all the rest of the decisions flow from that.



There are a lot of ways to do this. There are a handful of good ways to do this. There is no ONE right way, and no ONE best way.


Don't make this complicated. Water flows from high pressure to low pressure. Unless there are valves in the way (check valves or regular valves), the pressure equalizes everywhere in the system. You need ONE controller, but you can have multiple pressure tanks if you want to. You can also have booster pumps.

Take that basic information and figure out what works for you. It's that simple.

 

[Deere Dude]

I think you got it figured out by now, but I might add one thing I would do if it isn't to much trouble with the distances. I would run one line to the guest house where the tank and switch are located. I would then run a line from a valve in the guest house to the future house. All valving would be in the house so either one could be shut off without affecting the other.

 

[Valveman]

I'm confused now. Some are saying to run a single line from the guest house and then split it. Others are saying to run two main lines (one to each house) and just have the controller in the guest house garage.

With a normal pressure switch/pressure tank, you can tee off at the well to one house and have the tank and switch at the other house, as long as you don't put any check valves above ground.

But you should check with the manufacture, as I don't think you can do that with a VFD system. At least I know you cannot do this with the Sub Drive/Mono Drive type systems. The transducer is basically at the dead end of a line when the other house is using water, and the pressure will oscillate rapidly. I know this because I use a Cycle Stop Valve to solve this problem for people everyday. They go back and install a Cycle Stop Valve before the tee at the well head. The CSV1A is set slightly lower than the set point of the VFD. This keeps the pressure transducer from seeing the set point pressure, the pump just runs at full speed, and the CSV1A keeps the pressure constant no matter which house is using water.

I think with the VFD system you will need to bring all the water past the pressure transducer before you tee to the other house, or the pressure will fluctuate. At least I know it does with the Sub Drive systems.

 

[turnkey4099]

With a normal pressure switch/pressure tank, you can tee off at the well to one house and have the tank and switch at the other house, as long as you don't put any check valves above ground.

But you should check with the manufacture, as I don't think you can do that with a VFD system. At least I know you cannot do this with the Sub Drive/Mono Drive type systems. The transducer is basically at the dead end of a line when the other house is using water, and the pressure will oscillate rapidly. I know this because I use a Cycle Stop Valve to solve this problem for people everyday. They go back and install a Cycle Stop Valve before the tee at the well head. The CSV1A is set slightly lower than the set point of the VFD. This keeps the pressure transducer from seeing the set point pressure, the pump just runs at full speed, and the CSV1A keeps the pressure constant no matter which house is using water.

I think with the VFD system you will need to bring all the water past the pressure transducer before you tee to the other house, or the pressure will fluctuate. At least I know it does with the Sub Drive systems.

Thanks, I had forgotten about, and have no experience with, constant pressure systems.