PoolDoc
06-23-2018, 09:02 PM
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How Much Does Pump Efficiency Matter?
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TL;DR:
The difference in electrical operating cost between efficient & inefficient systems can be huge, far more than I would have guessed.
Worst case is with an infloor cleaning systems and a single speed pump operating 24 hrs/day;
Best case is with no infloor system and a two speed pump operating on HI 1 hr/da and on LO 12 hrs/day.
Worst case? $2,748/yr or $230/month for electricity
Best case? $155/yr or $13/month.
The difference? Almost $2,600 per year!
Take home? A pool timer, even with professional installation, will pay for itself in less than 6 months of operation. Replacing a working 1 speed with a 2 speed will take several years to recover; replacing a broken pump with 2 speed instead of a 1 speed may take 24 months of operation.
Equipment examples at the bottom of the page.
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OK, folks.
I've been driving myself nuts trying to work out optimized pump/filter/valve/piping sets for this page, Matched Pool Equipment Sets (http://www.poolforum.com/pf2/showthread.php/29224)
I've done this dozens of times for large commercial pools. But the guys that make the big stuff publish the test data and flow data on their equipment in easy-to-find and easy-to-use formats. But residential equipment? They bury that information! It is HARD to dig it out and HARD to get it into a usable form.
So, for a break, I set up a simple test case, to compare pump ops on a simple standard pool:
30,000 gallons
2 speed pump
with or with/out infloor cleaning
$0.15/kilowatt/hour
63 gpm
20 psi base system head loss (46')
40 psi system head loss with infloor cleaning
Guess what? I am STUNNED at the results. I should have done this, years ago.
Here's a shocker: if you consider a basic 6 hour per day run, with an optimized Whisper Flo pump with an energy efficient motor, and compare it with a non-energy efficient Super pump . . . the differnce is significant, but not huge: $287 (90% elec. eff; 70% hydraulic eff) vs $406 (80% elec. eff; 55% hydraulic eff), but it's more than enough to pay the difference between a SuperPump and the more expensive WhisperFlo
The results of using Caretaker-like infloor cleaning systems is no surprise: I've long known that they were massive energy hogs. But the magnitude of the difference was surprising, at least to me:
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Run time -- Run time ---- HP ------ Gallons
-- HI ------- LO ------- Req'd ----- circulated ---- $'s/day ------ $'s/mo ------ $'s/year
-- 24 ------- 0 --------- 2.0 ------- 90,000 -------- $4.24 --------- $127 -------- $1,624
--- 6 ------- 0 --------- 2.0 ------- 22,000 -------- $1.11 ---------- $33 ---------- $406
--- 1 ------- 12 -------- 2.0 ------- 18,000 -------- $0.43 ---------- $13 ---------- $155
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With Caretaker
-- 24 ------- 0 --------- 2.0 ------- 90,000 -------- $7.53 --------- $226 -------- $2,748
--- 8 ------- 0 --------- 2.0 ------- 30,000 -------- $2.51 ---------- $75 ---------- $916
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So . . . what's the difference between a well operated pool with a 2 speed pump, and a well operated pool with a Caretaker in-floor system? In electrical costs alone, the difference is nearly $800 per year!
And the difference between a well operated 2 speed system, versus a poorly operated Caretaker system is HUGE! You can hire a year round pool service company for less!
___________________________________
How Much Does Pump Efficiency Matter?
___________________________________
TL;DR:
The difference in electrical operating cost between efficient & inefficient systems can be huge, far more than I would have guessed.
Worst case is with an infloor cleaning systems and a single speed pump operating 24 hrs/day;
Best case is with no infloor system and a two speed pump operating on HI 1 hr/da and on LO 12 hrs/day.
Worst case? $2,748/yr or $230/month for electricity
Best case? $155/yr or $13/month.
The difference? Almost $2,600 per year!
Take home? A pool timer, even with professional installation, will pay for itself in less than 6 months of operation. Replacing a working 1 speed with a 2 speed will take several years to recover; replacing a broken pump with 2 speed instead of a 1 speed may take 24 months of operation.
Equipment examples at the bottom of the page.
___________________________________
OK, folks.
I've been driving myself nuts trying to work out optimized pump/filter/valve/piping sets for this page, Matched Pool Equipment Sets (http://www.poolforum.com/pf2/showthread.php/29224)
I've done this dozens of times for large commercial pools. But the guys that make the big stuff publish the test data and flow data on their equipment in easy-to-find and easy-to-use formats. But residential equipment? They bury that information! It is HARD to dig it out and HARD to get it into a usable form.
So, for a break, I set up a simple test case, to compare pump ops on a simple standard pool:
30,000 gallons
2 speed pump
with or with/out infloor cleaning
$0.15/kilowatt/hour
63 gpm
20 psi base system head loss (46')
40 psi system head loss with infloor cleaning
Guess what? I am STUNNED at the results. I should have done this, years ago.
Here's a shocker: if you consider a basic 6 hour per day run, with an optimized Whisper Flo pump with an energy efficient motor, and compare it with a non-energy efficient Super pump . . . the differnce is significant, but not huge: $287 (90% elec. eff; 70% hydraulic eff) vs $406 (80% elec. eff; 55% hydraulic eff), but it's more than enough to pay the difference between a SuperPump and the more expensive WhisperFlo
The results of using Caretaker-like infloor cleaning systems is no surprise: I've long known that they were massive energy hogs. But the magnitude of the difference was surprising, at least to me:
___________________________________
Run time -- Run time ---- HP ------ Gallons
-- HI ------- LO ------- Req'd ----- circulated ---- $'s/day ------ $'s/mo ------ $'s/year
-- 24 ------- 0 --------- 2.0 ------- 90,000 -------- $4.24 --------- $127 -------- $1,624
--- 6 ------- 0 --------- 2.0 ------- 22,000 -------- $1.11 ---------- $33 ---------- $406
--- 1 ------- 12 -------- 2.0 ------- 18,000 -------- $0.43 ---------- $13 ---------- $155
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With Caretaker
-- 24 ------- 0 --------- 2.0 ------- 90,000 -------- $7.53 --------- $226 -------- $2,748
--- 8 ------- 0 --------- 2.0 ------- 30,000 -------- $2.51 ---------- $75 ---------- $916
___________________________________
So . . . what's the difference between a well operated pool with a 2 speed pump, and a well operated pool with a Caretaker in-floor system? In electrical costs alone, the difference is nearly $800 per year!
And the difference between a well operated 2 speed system, versus a poorly operated Caretaker system is HUGE! You can hire a year round pool service company for less!
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