Variable speed pump worth the added cost$

Poolecw

Member
Apr 5, 2019
16
NW Ga
My installer says that a variable speed pump will cost $800 more than the single speed. I dont know which specific models he is quoting. But I do know he uses Jandy only.

Question is this, is there a decent ROI on the variable speed pump? My pool will be 18 x 36. I have seen a range of figures online. I know that true savings are based in the kwh saved over the life of the pump. I'll figure that out once I know which models he is quoting.
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
15,664
Tucson, AZ
If you're building a new pool, then it makes no sense to NOT get a variable speed pump. The cost difference is inconsequential compared to the overall build cost and you get the added benefit of being able to save money right away. Also, some utilities will give out rebates for using variable speed pumps, although many limit it to swapping out an old single speed for a new variable speed. Best to check with your electric utility company about any rebate offers. Even a 2-speed pump is a much better option than a single speed pump IF (and this is the big IF), the pool builder designs the plumbing so that everything that needs to be run can be at the low speed setting (you only use high speed for cleaning and other one-off purposes).

Sometimes builders push single speed pumps because they're "set in their ways" and they know what they know and build a pool that they "know how to build". You see this with automation a lot where an old-school builder just wants to install analog intermatic timers rather than learn how to install and program an automation panel. They get pushed into doing it buy the customer and then they make a mess of it because they're unfamiliar with how to do it properly and don't want to bring in an equipment rep or another service person to do the job right as that eats into their profit.
 

cfherrman

TFP Guide
May 10, 2017
2,279
Hays, Kansas
I ran the numbers for a friend, apples to oranges but still relevant

Single speed was $60 a month

VSP was $20

To figure yours, take your single speed hp, convert to watts, times hours run per day times energy price times 30 days. 2hp = 1491 watts x 8 hours (generic run time) 11,928 watts, times .11/kw time 30 days = $39.36

VSP are typically 200-250 watts run 24/7

If your trying to make roi a two speed pump does 90% of a VSP, you just don't get as much control from it.
 

CJadamec

TFP Expert
Apr 29, 2016
2,390
Quaker Hill, CT
As the others said yes a VS pump is worth the cost especially when building new. It becomes an even bigger yes if you are adding any of the following things to your pool:
Automation
Solar panels
Heaters
Water fountains, slides, or falls
Gas or heat pump heaters
Salt water chlorine generators

The more items on that list you have the more money a VS pump will save you on pump running costs.
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
15,664
Tucson, AZ
I don’t believe the pump HP equates to electrical energy by simple unit conversion. The pump’s horsepower is hydraulic power which is different from the electrical power. @mas985 has spreadsheets with many different pumps in it that uses actual data for each motor type and pump. His spreadsheets can give you a very accurate comparison of pump costs.
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
12,624
Pleasanton, CA
THP is the output of the motor shaft at max load. The electrical input power is dependent on the efficiency of the motor and the actual load. If you assume that the motor efficiency is 75%, there is a one to one relationship between THP and input kw. But it is a very rough estimate and can be off by quite a bit. The spreadsheet in my signature should improve the estimate.
 

cfherrman

TFP Guide
May 10, 2017
2,279
Hays, Kansas
Hp and watts are the same thing (energy), but are they measured on input or output, which I don't know, but in this example, we are using the same calculations so both cost examples would be off by the same factor and still be able to examine a cost benefit from them