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How & why to choose & install a water pressure booster pump:
This article describes the use of water pressure boosting systems that add a pump and pressure tank to improve water pressure and flow, including improving water pressure & flow on the upper floors of tall buildings.
We explain what a booster pump system is, what components are needed to improve building water pressure, and how to decide if a booster pump or pump and pressure tank set-up is the right repair for bad water pressure in your building. In FAQs & Q&As at the end of this article we discuss adding booster pumps & tanks in series.
We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.
When and Why are Water Pressure Booster Systems Needed
Some community water supplies may provide only modest incoming water pressure, perhaps at 30 psi or even less. Some examples of low water pressure supply sources even where community or municipal water supply is provided are listed here.
Effect of building height on water pressure:
The Home Reference Book points out that Gravity is another source of pres-
sure loss. Energy is required to push the water uphill. For every one foot we push water up, we lose 0.434 psi. Another way of saying this is that it takes one psi to move water up 2.31 feet.
A plumbing system will typically lose eight psi of water pressure in a two-story house, getting the water from the basement up to the second floor bathroom. With no water flowing, the static pressure at the street main may be 60 psi, but the static pressure at the second floor basin might be 51 psi. Houses that are above the street or have third story plumbing fixtures, have a pressure disadvantage.
[Click to enlarge any image]
Other Explanations of Poor Water Pressure where a Booster Pump & Pressure Tank May be Helpful
Homes at the end of a water supply line:
Community water supply systems serving just a few or even many homes, but with some homes near the end of the system
Buildings located high above a water supply line:
or located far uphill from the pumping station receiving only modest incoming water pressure, perhaps less than 30 psi.
Tall residential properties requiring additional water pressure to serve upper floors.
For a tall home connected to a community water supply providing incoming water at only 30 psi, for example, the top floor may see 17 psi unless a booster pump and pressure tank are installed.
(Very tall buildings such as skyscrapers and offices and multi-story apartment buildings are more likely to install a rooftop water supply tank which is fed by a pump from street level but which in turn provides water down through the building by gravity.) Sketch at above left provided by courtesy of Carson Dunlop Associatyes
Gravity water systems:
Community water supply systems serving many homes but supplying water only during certain hours of the day, or only at very low pressure.
For example San Miguel de Allende, Mexico, with a population of about 100,000 people, is served by nine water wells and pumping stations. But water is delivered to most homes by gravity, and in some seasons, only at certain hours of the day. A photo of a rooftop water storage system of this type can be seen
Problems with the water water service pipe connecting the home to city water mains: Even if a municipal water system gives good pressure and quantity, as the Home Reference Book points out, the city's own water shutoff
valve outside but near the property line may also restrict flow or the supply line from the street to the house may be undersized, damaged or leaking.
Long runs of relatively small (1/2-inch diameter) pipe result in considerable pressure drop, especially with more than one fixture flowing.
Solutions include replacement with larger pipe or shortening the runs, but in some cases homeowners may try adding a local booster pump instead.
Adding plumbing fixtures (a new bathroom, for example) without enlarging or adding pipes often leads to pressure complaints.
A crimped, damaged or clogged pipe within the house will adversely affect pressure. This is common with amateurish work. On a private system, a defective, undersized or poorly
adjusted pump will result in poor pressure. Individual faucets may also be defective.
Homes on gravity water systems such as we describe in the San Miguel de Allende case usually install a rooftop water tank or cistern to which water is replenished periodically. The rooftop water cistern provides water to the local building whenever it is needed.
But some homes in such a community may because of their location or construction or because they have no high spot to place their water tank, have only very low water pressure.
What are the Components of a Water Pressure Boosting System
Our sketch, courtesy of Carson Dunlop Associates and edited by the author shows a simple one line jet-pump and pressure tank connected to the incoming water line in a building. Our photo at page top shows a typical water pressure booster pump and tank system for sale at Don Pedro's Ferreteria in San Miguel de Allende.
The incoming community water supply line which normally is fed through a pressure regulator and into building supply piping is first connected to a water pump, usually a 1-line jet pump. The pressure regulator control is not shown in this sketch.
The water pump is in turn connected to a pressure tank, possibly a large one to give a good high pressure water supply to the building.
As water is drawn into the home (someone turns on a faucet) the pressure tank feeds pump-boosted water pressure to the building, and as water pressure drops in the water tank, the jet pump draws more water from the community supply line, boosting its pressure into the pressure tank.
Typically the booster pump pressure control switch will be set to operate in the 30-50 psi range, providing good water pressure to the building.
In a private well water supply system this pump and tank combination may be connected directly to the well, that is, the incoming water line shown in the left of the sketch is connected to a foot valve immersed in the water well.
What kind of water pressure booster pump do we need?
The reason that a typical residential property needs just a one-line jet pump to provide its water pressure boost is that there is already water arriving at the building under some pressure - the pump does not have to combine lift of the water from deep in the ground to high in the building.
Our photo of a pressure booster pump and tank system at left (and at page top) shows that stainless steel parts were used to enclose the pump parts: this system is designed for outdoor use in a non-freezing climate. You can see the pressure gauge and the gray box housing the pump pressure control switches above the stainless-steel covered pump assembly itself.
Tankless water pressure booster systems are discussed
Do we need a more powerful water pump or larger diameter water supply piping?
Some water pressure booster applications may require a more powerful pump than the type we discuss here, particularly if the anticipated water flow or usage rate in the building is high.
Carson Dunlop Associates's chart at left explains that in an individual plumbing system (that is, changing nothing but water flow rate), the water pressure observed at a fixture (and in the piping) will drop off significantly as the water flow rate increases.
This chart explains why the water pressure in your shower may fall off substantially during your bathing if someone else in the building flushes a toilet or turns on the dishwasher.
The chart also demonstrates that using larger diameter piping for the water supply in a building can significantly reduce the pressure drop when multiple fixtures are running at the same time.
Using a Booster Pump to Improve Water Pressure on the Upper Floor of a Building
When incoming water pressure at a building is low, a water pressure "booster pump" may be installed on upper building floors or on a building roof to provide improved water pressure for the occupants of upper building floors.
If the incoming water pressure is from a municipal system and the building is just two or three floors high, the booster pump might be on ground level, as we described at the start of this article.
But if the incoming water pressure at a building is being provided by a well pump and water pressure tank system, and if the building is taller than three floors, the existing well pump may not be capable of delivering adequate water pressure nor adequate water floor to occupants of a fourth or higher floor.
Installing a Booster Pump for Water Pressure on the Fourth Floor of a Residential Building
Beginning on the 4th floor of such a building, install an additional pressure tank next to the second pump.
The ground floor pump will send water into the incoming pipe connection of your 4th floor pump itself.
We are assuming that your 4th floor pump will be a 1-line jet pump - that is, a single pipe connects to the pump inlet port and a single pipe connects from the pump outlet to the inlet connection of a pressure tank.
Fourth floor cold water piping should be fed by the outlet connection on the pressure tank.
In our one line jet pump photo (left) the black plastic pipe coming up from lower left is attached to the pump's inlet port where an internal check valve prevents water from siphoning back out of the pump and tank into the well when the pump shuts down.
At the top right of this pump you can just make out the water connection leaving the pump where it heads up into a copper pipe.
The 4th floor pump will turn on when the pressure switch connected to its 4th floor pressure tank senses pressure dropping below the cut-in point, and it will cut "off" when the 4th floor pump has boosted pressure in your 4th floor tank up to the cutout pressure.
We expect that given that the 4th floor pump will have always at least some incoming water pressure, though low, it should be able to add additional lift t boost the 4th floor pressure as you want.
The "lift" capacity of a water pump that is a one-line jet pump is a little under 10 meters - but that's without any incoming pressure to the pump from the one located on the 1st floor.
Mark Cramer Inspection Services Mark Cramer, Tampa Florida, Mr. Cramer is a past president of ASHI, the American Society of Home Inspectors and is a Florida home inspector and home inspection educator. Mr. Cramer serves on the ASHI Home Inspection Standards. Contact Mark Cramer at: 727-595-4211 mark@BestTampaInspector.com
John Cranor is an ASHI member and a home inspector (The House Whisperer) is located in Glen Allen, VA 23060. He is also a contributor to InspectApedia.com in several technical areas such as plumbing and appliances (dryer vents). Contact Mr. Cranor at 804-747-7747 or by Email: firstname.lastname@example.org
Thanks to reader Ahmed Hamza for discussing the use of water pressure booster pumps and the installation of water pumps in series to improve water pressure on upper building floors. Mr. Hamza is in Cairo, Egypt where although he is not a plumbing professional, he works work with Calpeda Pumps, an Italian company that produces a wide range of electric pumps, including self-priming pumps type NGM, single phase 230V. Calpeda S.p.A., Calpeda Group,
Via Roggia di Mezzo, 39 - 36050 Montorso Vicentino - Vicenza / Italy
Tel. + 39 0444 476 476 Fax. + 39 0444 476 477
E-mail: email@example.com The company states: "Calpeda, a company leader in electric pump industry, is part of an industrial group that embodies metal materials foundries, companies producers of submersible bore hole pumps, a company operating in spa bath and shower industry and an IT company."
Access Water Energy, PO Box 2061, Moorabbin, VIC 3189, Australia, Tel: 1300 797 758, email: firstname.lastname@example.org Moorabbin Office: Kingston Trade Centre, 100 Cochranes Rd, Moorabbin, VIC 3189
Australian supplier of: Greywater systems, Solar power to grid packages, Edwards solar systems, Vulcan compact solar systems, water & solar system pumps & controls, and a wide rage of above ground & under ground water storage tanks: concrete, steel, plastic, modular, and bladder storage tanks.
Smart Tank, Installation Instructions [ copy on file as /water/Smart_Tank_Flexcon.pdf ] - , Flexcon Industries, 300 Pond St., Randolph MA 02368, www.flexconind.com, Tel: 800-527-0030 - web search 07/24/2010, original source: http://www.flexconind.com/pdf/st_install.pdf
Typical Shallow Well One Line Jet Pump Installation [ copy on file as /water/Jet_Pump_Grove_Elect_Jet_Pumps.pdf ] - , Grove Electric, G&G Electric & Plumbing, 1900 NE 78th St., Suite 101, Vancouver WA 98665 www.grovelectric.com - web search -7/15/2010 original source: http://www.groverelectric.com/howto/38_Typical%20Jet%20Pump%20Installation.pdf
Typical Deep Well Two Line Jet Pump Installation [ copy on file as /water/Jet_Pump_Grove_Elect.pdf ] - , Grove Electric, G&G Electric & Plumbing, 1900 NE 78th St., Suite 101, Vancouver WA 98665 www.grovelectric.com - web search -7/15/2010 original source: http://www.groverelectric.com/howto/38_Typical%20Jet%20Pump%20Installation.pdf
Water Fact Sheet #3, Using Low-Yielding Wells [ copy on file as /water/Low_Yield_Wells_Penn_State.pdf ] - , Penn State College of Agricultural Sciences, Cooperative Extension, School of Forest Resources, web search 07/24/2010, original source: http://pubs.cas.psu.edu/FreePubs/pdfs/XH0002.pdf
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
Carson, Dunlop & Associates Ltd., 120 Carlton Street Suite 407, Toronto ON M5A 4K2. Tel: (416) 964-9415 1-800-268-7070 Email: email@example.com. The firm provides professional home inspection services & home inspection education & publications. Alan Carson is a past president of ASHI, the American Society of Home Inspectors. Thanks to Alan Carson and Bob Dunlop, for permission for InspectAPedia to use text excerpts from The Home Reference Book & illustrations from The Illustrated Home. Carson Dunlop Associates' provides extensive home inspection education and report writing material.
The Illustrated Home illustrates construction details and building components, a reference for owners & inspectors. Special Offer: For a 5% discount on any number of copies of the Illustrated Home purchased as a single order Enter INSPECTAILL in the order payment page "Promo/Redemption" space.
TECHNICAL REFERENCE GUIDE to manufacturer's model and serial number information for heating and cooling equipment, useful for determining the age of heating boilers, furnaces, water heaters is provided by Carson Dunlop, Associates, Toronto - Carson Dunlop Weldon & Associates Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on any number of copies of the Technical Reference Guide purchased as a single order. Just enter INSPECTATRG in the order payment page "Promo/Redemption" space.
The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. Field inspection worksheets are included at the back of the volume.
Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on these courses: Enter INSPECTAHITP in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
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