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sparks

Jan 9, 2007, 1:09 PM

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Another take on water system

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We have city water in the street and would like to bypass our well. The problem is with city water pressure feeding a 3 story house. Currently we pump well water to a holding tank on top of the 3rd floor roof for pressure.

Cutting the city water into pipes on the first floor would be a failure for pressure at higher altitudes .... so I was thinking of running the city water to the gravity tank directly with a float shutoff. Any idea how much pressure from the street would be required to keep the gravity tank filling.

The other option would be to have a ground level holding tank and let the pump do what it does now. At least we would be bypassing the well. The well is about 4 feet wide and 30 feet deep and must be a repository for some nasty things. Can't even see water at the bottom.

Sparks Mexico - Sparks Costalegre

Rolly / Moderator

Jan 9, 2007, 1:21 PM

Post #2 of 10 (1994 views)

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Re: [sparks] Another take on water system

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You will surely need a tank at ground level from which you can pump into the house. This will allow you to pump directly to the house and not have to use the gravity feed from the roof, thus giving better pressure for showers and washing machines. My house is plumbed like that. Works well.

Rolly Pirate

E-visit me http://Rollybrook.com
On Facebook as Rolly Brook

sparks

Jan 9, 2007, 4:47 PM

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Re: [Rolly] Another take on water system

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But Rolly ... that has to be a pressure sensitive pump rather a than a float level pump no? (is there such a thing) I'd prefer not to have the pump come on every time a faucet gets turned.

I assume you are one level and are living alone. Big difference with 3 levels and up to 10 people.

Sparks Mexico - Sparks Costalegre

Ron Pickering W3FJW

Jan 9, 2007, 5:05 PM

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Re: [sparks] Another take on water system

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A medium size expansion tank with an internal pressurized bladder should handle that problem......
Getting older and still not down here.

sparks

Jan 9, 2007, 5:09 PM

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Re: [Ron Pickering W3FJW] Another take on water system

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Oh ... now I have to take a leak

In Mexico and costly?

Sparks Mexico - Sparks Costalegre

Ron Pickering W3FJW

Jan 9, 2007, 5:26 PM

Post #6 of 10 (1970 views)

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Re: [sparks] Another take on water system

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I actually should have said a water pressure tank like they use on wells to keep the well pump from cycling too hould work fine with your problem.

http://www.hammerzone.com/...ure_tank/replace.htm
Getting older and still not down here.

Rolly / Moderator

Jan 9, 2007, 6:12 PM

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Re: [Ron Pickering W3FJW] Another take on water system

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My pump serves two single story houses with a total of 6 people. It has a small pressure tank, so it does cycle often. There are larger tanks that will cycle less often.

You can use the pump to move the water to a holding tank on the roof, or you can use the pump to feed the house directly. But either way you will still pump the same amount of water.

Rolly Pirate

E-visit me http://Rollybrook.com
On Facebook as Rolly Brook

Papirex

Jan 9, 2007, 6:12 PM

Post #8 of 10 (1963 views)

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Re: [sparks] Another take on water system

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Sparks, It wouldn’t take a pressure sensitive pump, but a pressure sensitive switch to start the pump each time a faucet was opened. This type of system has been used for several decades in RVs, Motor homes, travel trailers, self-contained pickup campers etc. They are called demand water systems.

The pump will start every time any water is used, this may shorten the service life of the pump slightly, but probably by a negligible amount. The main possible disadvantage to a demand system is that when the power fails, you will have no water available until the power is restored. I would hate to be caught in the shower with my hair full of shampoo when the power fails in a house with a demand water system.

The reliability of the power supply in a given area would be a big consideration for me before I would opt for a demand water system. A modern pressure tank with a diaphragm in it would probably be a better option if higher water pressure were desired.

In a 3-story house, I don’t think I would rely on a centrifugal pump as is usually used here in Mexico for any kind of pressure on the third floor. Under ideal conditions, a centrifugal pump will only lift water 32 feet at sea level. Because of resistance in the pipes, and other factors, as a practical matter, in most instances centrifugal pump will usually only lift water an average of 27 feet. Any water lifted to the third floor by a centrifugal pump, would have practically no pressure by the time it reached that height.

A displacement pump, while slower, would be a viable alternative for lifting water any higher than 27 feet.

A tinaco on the roof would be the most reliable way to get any water pressure on the third floor if you are using a centrifugal pump. Since water produces just slightly less than ½ pound of pressure per foot of elevation, you would probably have about 5 pounds of pressure in a third floor shower, and about 12 pounds of pressure on first floor fixtures.

I posted the formula for calculating gravity water pressure a few years ago, if you do a search you will find it.

Rex

"The supreme happiness of life is the conviction that we are loved" - Victor Hugo

Ron Pickering W3FJW

Jan 9, 2007, 6:23 PM

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Re: [Rolly] Another take on water system

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You do pump the same amount of water but, with a pressure tank the pump doesn't cycle as ofter thereby saving wear & tear on the pump and it also limits the surge current necessary to start up the pump which helps keep the elec bill down by having the pump startup less often.
Getting older and still not down here.

sparks

Jan 10, 2007, 1:47 AM

Post #10 of 10 (1943 views)

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Re: [sparks] Another take on water system

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Only problem with these fancier tanks is that this is a rental house. While I'm willing to pay to connect city water ... I didn't want to go way beyond that in cost.

Sparks Mexico - Sparks Costalegre