Post by RRusso on Feb 15, 2005 4:27:46 GMT -5
There are many different types of water-moving pumps and motors used for water features. You must plan for, select and install/engineer the right pump for your particular application: The pump type, size and orientation must be matched with the water-effects' size, configuration, plumbing/filtration/circulation systems to produce your desired results at a minimum cost.
Who owns your public utility? You do! Re-read the above paragraph; the savings from emphasizing the need for diligent pump research are the best money I can help you with.
Costs: Initial & Ongoing
Often, in the long run, the single largest expense of water effects is the electrical cost of running the pump(s) for water purification, filtration, aeration, circulation and ornament. A frequent approach to reducing operating costs is to shorten pumping operation time. In general, this is a very poor idea, especially in biological systems. In "living" systems, water effects with live plants, and/or fishes the pumps should/must run generally 24 hours a day.
Actual operating costs for running a pump, including purchase, service factor, application and energy can be determined with your manufacturer/distributor representative or a
pump engineer. Alternatively, the largest expense-factor, electrical cost may be easily calculated using the formula of multiplying volts times amps consumption and dividing out by your cost per kilowatt. If you need help, do call on your local utility and they will gladly help you.
Sizing:
How much pump is enough? As usual, it depends; principally oni what effect is desired aesthetically & functionally. There are systems that are designed and built to have no to very little pumping. Then there are features that by virtue of poor, inadequate lay-out, depth, over-feeding, inappropriate size filters, and/or improper maintenance cannot be pumped enough.
When specifying a pump it is necessary to determine the water pressure (Head) and flow-rate (gallons per minute, hour) that the pump must supply.
Basically:
If you're involved with an effect that has an appropriate filter system, plumbing, not too much food & fertilizer, and do not want it to be "out of balance" chemically or biologically, you are ready to ask the question: What is it I want from this feature that pumping will get me? What sights & sounds? What degree of clarity, cleanliness?
You do not need an advanced degree in fluid hydraulics to get beyond this point! By following the information in the Sections on plumbing and electrical topics, you should be able to assess the correct pump.
Most water features of a few hundred to a couple of thousands of gallons will perform functionally by circulating the water through the whole system about once per hour. Another rule of thumb is to select a pump and motor that will give you one gallon of flow per minute per foot surface area of the effect. Where in doubt, seek experienced help, or go to the next size up in flow-rate. For consideration of the factors of matching of filters to pumps and flow rate, please see the various and several Sections in this book on Filtration.
I purposely underlined functionally in the paragraph above.
Aesthetically the "end-user" may desire more or less apparent flow. If less, due to overwhelmed falls, errant jets, filters et al., circulated water should be diverted back to the water feature below water, with less fanfare. If you want more circulation, this should present no problems as long as the configuration of your water effect and the mechanical parts can accommodate it.
Selecting A Pump:
Should be done with the help of people who know the product and it's applications. Bring a drawing of the system basin/s, plumbing, filtration and topography & ask for advice, given what sights and sounds you want to produce. The equipment distributor will match your needs to a power or system curve for the available pumps and give you the skinny on installation, initial and ongoing costs.
A note: selecting pumps by horse-power alone can be extremely mis-leading! Ask your dealer to show you how to interpret which pump/motor combination is right for your system.
There are ways you can educate yourself to be able to figure the relationships between head pressures, resistances due to fluid, piping and filters; see the references at the end of this piece.
Pump Types:
Emerged, Out of the Water:
For most medium-size water effects centrifugal "swimming-pool-type" pumps are used. Many other pumps of less revolutions per minute, more/less flow-rate/pressure, specialized volute/applications are available and definitely worth looking into for the long-run.
Swimming-pool pumps often use more electricity, but have the power to generate the head-pressure and flow-rate you may want them to, especially to back-wash filters. Due to a wide range of efficiencies, appropriate application, up-front and continuing costs it is of primary importance to use the "right" pump.
Make sure and look into the possibility of two-speed (much less cost of operation at lower, regular setting), and higher "rated" pump motors. Don't miss out on the opportunity of saving real money by getting the best pump/motor combination available for your application.
About being outdoors. It's no fun to replace pumps entirely let alone bearings regularly from exposure to the elements. Do provide at least a simple housing/cover for your pump. Here's an artificial rock that is water proof, strong and lightweight that can act as a ready cover. Color and texture can be matched to other landscape elements.
Who owns your public utility? You do! Re-read the above paragraph; the savings from emphasizing the need for diligent pump research are the best money I can help you with.
Costs: Initial & Ongoing
Often, in the long run, the single largest expense of water effects is the electrical cost of running the pump(s) for water purification, filtration, aeration, circulation and ornament. A frequent approach to reducing operating costs is to shorten pumping operation time. In general, this is a very poor idea, especially in biological systems. In "living" systems, water effects with live plants, and/or fishes the pumps should/must run generally 24 hours a day.
Actual operating costs for running a pump, including purchase, service factor, application and energy can be determined with your manufacturer/distributor representative or a
pump engineer. Alternatively, the largest expense-factor, electrical cost may be easily calculated using the formula of multiplying volts times amps consumption and dividing out by your cost per kilowatt. If you need help, do call on your local utility and they will gladly help you.
Sizing:
How much pump is enough? As usual, it depends; principally oni what effect is desired aesthetically & functionally. There are systems that are designed and built to have no to very little pumping. Then there are features that by virtue of poor, inadequate lay-out, depth, over-feeding, inappropriate size filters, and/or improper maintenance cannot be pumped enough.
When specifying a pump it is necessary to determine the water pressure (Head) and flow-rate (gallons per minute, hour) that the pump must supply.
Basically:
If you're involved with an effect that has an appropriate filter system, plumbing, not too much food & fertilizer, and do not want it to be "out of balance" chemically or biologically, you are ready to ask the question: What is it I want from this feature that pumping will get me? What sights & sounds? What degree of clarity, cleanliness?
You do not need an advanced degree in fluid hydraulics to get beyond this point! By following the information in the Sections on plumbing and electrical topics, you should be able to assess the correct pump.
Most water features of a few hundred to a couple of thousands of gallons will perform functionally by circulating the water through the whole system about once per hour. Another rule of thumb is to select a pump and motor that will give you one gallon of flow per minute per foot surface area of the effect. Where in doubt, seek experienced help, or go to the next size up in flow-rate. For consideration of the factors of matching of filters to pumps and flow rate, please see the various and several Sections in this book on Filtration.
I purposely underlined functionally in the paragraph above.
Aesthetically the "end-user" may desire more or less apparent flow. If less, due to overwhelmed falls, errant jets, filters et al., circulated water should be diverted back to the water feature below water, with less fanfare. If you want more circulation, this should present no problems as long as the configuration of your water effect and the mechanical parts can accommodate it.
Selecting A Pump:
Should be done with the help of people who know the product and it's applications. Bring a drawing of the system basin/s, plumbing, filtration and topography & ask for advice, given what sights and sounds you want to produce. The equipment distributor will match your needs to a power or system curve for the available pumps and give you the skinny on installation, initial and ongoing costs.
A note: selecting pumps by horse-power alone can be extremely mis-leading! Ask your dealer to show you how to interpret which pump/motor combination is right for your system.
There are ways you can educate yourself to be able to figure the relationships between head pressures, resistances due to fluid, piping and filters; see the references at the end of this piece.
Pump Types:
Emerged, Out of the Water:
For most medium-size water effects centrifugal "swimming-pool-type" pumps are used. Many other pumps of less revolutions per minute, more/less flow-rate/pressure, specialized volute/applications are available and definitely worth looking into for the long-run.
Swimming-pool pumps often use more electricity, but have the power to generate the head-pressure and flow-rate you may want them to, especially to back-wash filters. Due to a wide range of efficiencies, appropriate application, up-front and continuing costs it is of primary importance to use the "right" pump.
Make sure and look into the possibility of two-speed (much less cost of operation at lower, regular setting), and higher "rated" pump motors. Don't miss out on the opportunity of saving real money by getting the best pump/motor combination available for your application.
About being outdoors. It's no fun to replace pumps entirely let alone bearings regularly from exposure to the elements. Do provide at least a simple housing/cover for your pump. Here's an artificial rock that is water proof, strong and lightweight that can act as a ready cover. Color and texture can be matched to other landscape elements.