Horsepower Ratings vs. Actual Consumption

[gpnyv]

Thanks for the explanation.

Shouldn't they be selling pumps based on how much they will cost to operate - IE - consumption in KW/h? We all pay for watts, so it would make more sense to get electrical input and energy factor or a total pump power efficiency curve since wattage varies with the the amount of head.

It makes NO sense that people walk into a store and 5 different 1hp pumps will have 5 different actual input watts ranging from 746 to 2000+

This rating difference can mean $500+/yr in actual operation costs.

[mas985]

Shouldn't they be selling pumps based on how much they will cost to operate - IE - consumption in KW/h?

Until recently, that hasn't been a priority. The California Energy Commission now requires manufactures that sell pumps in California to measure their pumps and they now publish a database located here. The database has the flow rate and energy use for many pumps on three different plumbing systems.

The three plumbing conditions included in the database are:

• Curve-A which represents fairly restrictive plumbing typical of an AG pool or an IG pool with 1.5" pipe size.
• Curve-B which represents extremely high head loss conditions. Not many pools would fall in this category.
• Curve-C which represents less restrictive plumbing typical of pools using 2" pipe size.

So if you are so inclined, you can download the database in spreadsheet form and see what each of the pumps draw in terms of energy. But keep in mind, that a pump on your pool plumbing may draw more or less than that shown in the table.

However, if you are just interested in getting the most energy efficient pump, I can certainly help in that area. Generally, speaking, the smaller the pump, the less energy it will consume so just sticking with that will save energy. Second, a two speed or variable speed pump will reduce energy even further. But which is more cost effective depends on three primary factors:

Size of the pool
Run time of the pump (i.e. # turnovers per day, should be no more than 1/day)
Cost of electricity

Your plumbing setup has some influence as well such as pipe size and distance from the pool but these are secondary factors.

So if I can get some details on your setup and what you pay for electricity, I can help further.

[gpnyv]

Thanks for the information and the california energy comission link. It was very interesting.

I had the Hayward Super Pumps in 1hp, 1.5hp, and 2.0hp, as well as the hayward Tristar 1hp tested for flow vs. Amp draw.
The 1.0 hp Super pump was drawing 1600 watts at about 50ft of Head flow rate, the 1.5hp -2040 watts at 50ft of head, and the 2.0 hp 2400 watts at 50ft. The 1.0hp Tristar was Drawing around 1750w. THis was all on the same setup and using a valve and flow meter to vary restriction in the piping.
The 1.0hp tristar flowed more than the 2.0hp Super Pump for much less energy, but all of the pumps, regardless of the Hayward HP ratings consumed a lot more wattage than their nameplates.

[mas985]

Who did you have test the pumps because those numbers do not look correct?

[gpnyv]

Tested them in the lab at one of my clients. They make heat pumps, so the equipment is quite precise. The wattages above are rough averages of what we datalogged. We reduced flow to several GPM increments and kept datalogs of the amperage draws for each of the pumps.

[mas985]

The CEC measurements for the Superpump are well below what you measured so something is wrong. Are you sure the pumps weren't Super IIs instead of the Superpump? There is a big difference between the two.

The full rate 1 HP Tristar is within operating limits so that one I believe.