
A NEW WAY TO COMPARE POND PUMPS The Money Saver Pumps®, with their variable horsepower dial, or gas pedal, are so much more efficient than other pumps, we needed a simple way to show just how much better they are. While working on this comparison, we remembered the Creech Pump Index (CPI), which goes back 40 years to the Illinois Institute of Technology, where we did our work on a Ph.D. in Physical Chemistry. It is simple Physics. It compares the work done by a pump i.e., the flow against the pump head, versus the power used to do the work. I have never seen it used before for pond or pool pumps. It is simple to calculate: Creech Pump Index = {GPM x Pump head x Specific Gravity x %Pump Efficiency} / {Watts} Where GPM is gallons per minute, pump head (Ph) is the value for the given GPM, specific gravity is the density of the liquid (for water it is essentially =1). The %Efficiency is not usually given by the pump manufacturers, and usually is 60% or much less, but since we don’t know it, it is easiest to ignore it and just use 100% or 1, but please note as the pump %Efficiency goes down, so does the CPI. If you knew the %Efficiency at any one point, you could calculate it at all points. You would divide the CPI by it to get the Maximum CPI (MCPI), and then divide all the other points by the Maximum CPI to get the %Efficiency.The Creech Pump Index (CPI) is similar to the WATER HORSEPOWER: Water Horsepower = {(GPM x Pump head)/ 3,956} Brake Horsepower = Water Horsepower / %Pump Efficiency Electrical Horsepower = Brake Horsepower / %Motor Efficiency Unfortunately some manufacturers list their pumps’ amperage (amps), while others list the watts. Some pond owners do not know how to convert from one to the other. The correct conversions are as follows: Amps x Voltage = Watts or Watts / Voltage = Amps** Often the GPM (or GPH) is given at different pump heads. Now we can calculate the CPI for any pump. For example, let’s look at some of the publicly advertised pumps: For instance, the Jacuzzi 2speed SLR pumps are listed as follows:
The CPI is 1.8 for all 3 of these Jacuzzi pumps. The Sequence 2 HP K661.111 lists the amps as 25; with 2100 GPH @ 82’ Ph; 4200 GPH at 74 Ph; 6300 at 62 Ph; and 8160 at 43’ Ph. The Creech Index computes as 1.0; 1.8; 2.3; and 2.0. It is not the same because the %Efficiency at 43’ Ph is twice the efficiency at 82’ Ph; and with its most efficient performance at 62’ Ph. This is important information to know . However, if we average the CPI's for the Sequence 2 HP K661.111 it is 1.8, the same as the Jacuzzi pumps. The Superfalls 1/10 HP pump KJ7000LH has a CPI of 0.2. The 5/8 HP Little Giant 4,100 GPH pump has a CPI of 0.8. The 1 HP Money Saver Pump® has a CPI of 3 or more for all HP’s including 3/4, 1/2, 1/4, 1/6, 1/8, & 1/10. So the Creech Pump Index allows us to compare pumps and their energy efficiency, quickly and easily! It shows how revolutionary the Money Saver Pumps® are to the pond community. Using the Creech pump index you can at last easily compare pumps!
We have shown the Creech pump index allows all these factors to be taken into consideration. The resulting CPI is a measure of the energy efficiency of each pump. The larger the number the more energy efficient is the pump. These numbers run from 0.2 to 3.1 with the 3.1 CPI being 15 times more energy efficient than the 0.2 CPI. Try calculating the CPI for your pump! Here is a list of Creech Pump Indexes for some of the more popular pumps:
* amps shown for 230 volts **Actually to be rigorously correct for AC current we need to insert the power factor into these equations as follows: Amps x Voltage x Power factor = Watts or Watts / Voltage = Amps x Power factor The power factor is the cosine ø, where ø is the phase angle between the voltage and the amps, or ø is the angle between the vectors of Real Power and Apparent Power, and the vector opposite is the Reactive Power. Generally ø is = 0, except for inductive and capacitive components. This is especially important if one measures the amps, and then the voltage, in the field. For an inductive motor these will need to be corrected by the power factor. Unfortunately, the equipment needed to measure ø or the power factor, such as an oscilloscope, costs several thousand dollars. Fortunately, many motors list their power factor on the nameplate.

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