Need help with residential pressure boosting solution (City supply)

[lekalif]

Hi, we have somewhat low city water pressure (for our liking at least - approx. 30psi) on 1/2" copper supply from the city side of meter. We'd like to boost the pressure to around 50psi if possible. We have plans for a 2nd storey addition and are concerned the pressure upstairs will be lower than the main floor.
I am looking at the following setup and would like to know your suggestions;

(I think this is in the correct order from the meter)
Grundfos MQ3-35 pump
Cycle Stop Valve
30 gallon Well-mate bladder pressure tank
pressure switch

We currently have 1 3pc bath, 1 4pc bath, 2 toilets and have plans for 2 more bathrooms (probably 3pc each). We have a water filter system (2-stage) at kitchen sink that performs poorly to say the least! I think the box said minimum 40psi...not sure.

thks in advance for your advice!

sean

 

[Rutherfordman]

I am not as knowledgable as many here but I do design commercial domestic booster pumping systems for multi-story buildings. I am not familiar with the equipment you mention but one thing stands out as a possible problem. You say you only have a 1/2" supply from the meter. That small a line creates alot of friction loss in head once you start flowing any appreciable amount of water. This may create problems for the pump. I usually try to make sure that my suction pipe is one size larger than the pump inlet. For the fixtures you mention I would say at least a 3/4" or even a 1" line from the meter is needed.

 

[Sponsor]

 

[99k]

You have two problems. First, the minimum feed from the street should be 3/4" and that will cause a flow problem and pressure drop. Second, you have the pressure problem that will require a boost. You will loose approx. another 5 psi on the upper level (proposed addition) from head pressure losses. Talk to the water company and see what they can do for you with regard to both issues.

 

[Valveman]

I agree with Rutherfordman about the ½" supply line. You will probably need to either install a larger supply line or use a storage tank before the booster pump. If you put in a 500 gallon storage tank, the ½" line can fill it slowly. Then the booster pump, CSV, and pressure tank can supply the house with as much volume and pressure as needed.

Use one of the standard Grundfos or other brand of jet pumps. The MQ will not work with a CSV and it not a very dependable pump because of all the electronics. I always check out the Dumpsters behind the pump supply houses, and I find them to be full of MQ's and SQE's. This fact along with the number people who have called me about the problems with these type pumps makes me want to stay away from them completely.

 

[lekalif]

More info...

Hi guys, thanks for the speedy replies. I guess I should clarify the city supply is 1/2" copper. I talked to the city and this is apparently standard! Might be due to the fact the house is almost 60 years old and when they replaced the lead pipes many years ago, 1/2" copper is what they used.

When we bought the place, I removed the old galvanized pipe (AFTER the meter, our plumbing/pipes) and replaced it with 3/4".
Since then I've had a hunch it was the city supply that is causing the problem. Unfortunately replacing/upgrading to 3/4" supply (City side) or even 1" could mean lots of digging and lots of $$.

your thoughts?

sean

 

[Valveman]

Storage tank with a float valve, booster pump, CSV, bladder tank, pressure switch.

 

[FloridaOrange]

When we bought the place, I removed the old galvanized pipe (AFTER the meter, our plumbing/pipes) and replaced it with 3/4".

Your meter is likely a point of restriction. You may have somewhat satisfactory results if you went to a larger size meter.

Houses here typically have 3/4" supply on a 5/8" meter. Your current meter may restrict to 3/8".

 

[Speedbump]

What everybody is saying is unless you store water in a large tank so your pump can have the water it wants when it want's it, your just spinning your wheels. The 1/2" copper along with a meter that too may be a restriction in of itself can easily fill a 500 gallon tank over night, but to allow a pump with a 1-1/4" suction pulling from a 1/2" pipe to boost pressure is just asking too much.

 

[Alternety]

Slightly off the actual post but I see you are recommending a jet pump for the pressure boost. I have been curious about the best pump for this type of application. I have not found many positive displacement pumps suitable for the application and the alternative seemed to be centrifugal. I am trying to get 40/60 pressure from an unpressurized tank at about 25 GPM. Yes I need that.

Can anyone share the pros and cons of the pump types for this application.

 

[Valveman]

When boosting pressure from a city line, a jet pump is about the only option. When boosting from a tank or cistern, a jet or a submersible can be used. I like submersibles when possible. I only use jets when I have to.

 

[Speedbump]

I agree, the sub is the way to go, but if you have to stay with a jet for some reason, my SFH100 will do 27 gpm at 40 psi and will easily make 60 for shut off. This is with a 5 foot lift. If your pulling from an atmospheric tank, you can probably expect a bit more.