Energy savings from a 2 speed pump

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T

Technikal

0
Nov 2, 2016
51
Austin, TX
I recently changed from a full rated 1.5hp single speed pump motor to a 1.5hp dual speed pump motor. I've been tracking energy usage and thought I'd share my findings.

I'm comparing the 4 weeks ending 2/21/2018 to the 4 weeks ending 2/21/2017. Weather conditions were slightly colder in 2018, but we're on natural gas for heat, so the impact should be limited to just the impact of spending more time inside. I've also replaced a few CFL lights with LEDs as they burned out over the year, but otherwise all major appliances, systems and usage patterns are the same. I have a wife and young kids who don't fully understand that lights can be turn 'off' as well as 'on', so it's always great to find ways to save on energy use that they don't even know about:


OldPumpNewPump
KWh$KWh$
Max55.04.6837.53.19
Min35.33.0119.31.64
Median43.53.7124.32.07
Average44.63.8025.12.14
Total1196.9101.99678.057.76
Savings518.9$44.2343%


This should be one of my lowest KWh savings months since run times are short this time of year with no SWG. It will be one of my highest % savings months since no AC is running. Pretty easy way to put a decent dent in your energy usage.
 
Jimrahbe said:
Tech,

Looks good... I believe it should be almost illegal to run a single speed pump... :p

Thanks for the feedback..

Jim R.
Click to expand...

In some places, it is.

In California, a pump at 1.0 hp or larger has to be 2 speed or variable speed.

Some single speed pumps are rated at 0.98 hp to just miss the 1.0 hp limit.
 
Thanks for posting. I am currently struggling with the idea of single speed versus variable speed. The pool builder wants to charge $1200 to upgrade from a 2HP single speed Jandy FloPro to a variable speed model so it is no small sum. It’s marked up significantly based on my research so I was thinking about having him install the single speed and swapping out for a variable speed myself. Even buying both pumps it is a savings of almost $300, plus my electric company gives a $400 rebate.

How many hours are you running the pump in this example? Based on my research here, I will likely run the pump 4-6 hours per day for one turnover. At 13.3 cents per kWh and the pool being open 4-5 months per year, it still takes a few years to make up the difference in cost ($955 pump cost minus $400 rebate equals $555 net). But if I have to run the pump a lot during the plaster curing phase (some say 24 hours?). The window shortens fairly significantly.
 
I agree. Based on what I’ve seen, the cost difference is about $400. I assume the wholesale difference is probably lower but I would have reluctantly agreed to pay $600. $1200 is just too big of a difference for me to accept.
 
Captchaos said:
Thanks for posting. I am currently struggling with the idea of single speed versus variable speed. The pool builder wants to charge $1200 to upgrade from a 2HP single speed Jandy FloPro to a variable speed model so it is no small sum. It’s marked up significantly based on my research so I was thinking about having him install the single speed and swapping out for a variable speed myself. Even buying both pumps it is a savings of almost $300, plus my electric company gives a $400 rebate.
Click to expand...

Ya lost me. Is this a new build? Why would you need to buy the other pump? Why not buy the variable and put it on the pad and have your PB glue it in? The markup these guys get is something else. My Pentair cost me twice what I could have paid had I put it in myself. But then Pentair won't warrant it. So it kinda feels a bit like extortion. I tried the math: I could buy the second pump if the first one poops out without the warranty, and break even... I chickened out and paid the guy.

Back to the OP...

I was just very much enlightened by one of the TFP experts who questioned why I was filtering for so many hours. He taught me about the turnover myth, and that sanitation doesn't necessarily require all that much pumping. Pool clarity might, based on your environment, but sanitation not so much. In addition to pump types, maybe filter cycle lengths is something to look at when trying to save some dough. Try an hour less at a time until your water complains. Maybe no-up-front-cost savings has been lurking around all along...

I went an additional way... PV solar. This is my last home. In 5 or 6 years my panels will be mine and both my pool's and my house's electricity will be "free" forever! If you're not going to move any time soon, I'll go out on a limb and claim putting money into PV solar is the best way for you to cut your energy costs.
 
JamesW said:
Offer $600 for the upgrade or ask to be credited for the cost of the single speed pump and buy the variable speed pump on your own.
Click to expand...

Oh, I missed that! He wants $1200 extra for the variable? So, like, he's getting $1500+ for the variable? Yikes. Yah, what JamesW said!
 

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Technikal said:
I'm running the 2 speed pump on low for 8 hours a day. I was running the old pump 6-7 hours a day this time last year.

I use an swg for chlorine generation and that's what typically dictates my run times.
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SWG, right. Me, too, but not in winter, it’s too cold. So I’m down to 4.5 hours a day at 1500 RPM and water is still good (So far, that is!). You won’t need any extra hours on low speed for the SWG, as their chlorine output is not flow dependent. So you should be able to go back to the 6 or 7 hours you had before, as long as the water stays clear, yes?

I have solar, too, so that dictates hours and RPM during swim season. So I make up for what I can in the off season. I exaggerated a bit about the PV solar. I still try to be frugal with electricity where I can, because the more I save, the more I can pump the AC!
 
I read somewhere here that some two-speed pumps have a way to dial in the actual RPM for each speed. If yours has that feature, that might be another way to eek out a bit more savings. You’d just have to keep the flow above the minimum the SWG needs to function. So you’d set the run time for chlorine output, and the RPM for water clarity and skimming. Something like that...
 
Dirk said:
Ya lost me. Is this a new build? Why would you need to buy the other pump? Why not buy the variable and put it on the pad and have your PB glue it in? The markup these guys get is something else. My Pentair cost me twice what I could have paid had I put it in myself. But then Pentair won't warrant it. So it kinda feels a bit like extortion. I tried the math: I could buy the second pump if the first one poops out without the warranty, and break even... I chickened out and paid the guy.

Back to the OP...

I was just very much enlightened by one of the TFP experts who questioned why I was filtering for so many hours. He taught me about the turnover myth, and that sanitation doesn't necessarily require all that much pumping. Pool clarity might, based on your environment, but sanitation not so much. In addition to pump types, maybe filter cycle lengths is something to look at when trying to save some dough. Try an hour less at a time until your water complains. Maybe no-up-front-cost savings has been lurking around all along...

I went an additional way... PV solar. This is my last home. In 5 or 6 years my panels will be mine and both my pool's and my house's electricity will be "free" forever! If you're not going to move any time soon, I'll go out on a limb and claim putting money into PV solar is the best way for you to cut your energy costs.
Click to expand...


Yes, this is a new build. I asked about supplying the pump myself and received a firm “NO.” I thought about the warranty too, but it seems worth the risk to save the $300 and wind up with two pumps. I suppose I could potentially sell the single speed too and recoup some more costs.

I looked into solar pretty hard and can’t seem to make it work for me. My roof is somewhat complicated and we are 100% electric here (no natural gas so it’s even used for heat). Even the huge system that would have uglied up nearly my entire roof they were proposing was not going to generate all of my electricity in a single month (monthly average is approximately 4000 kWh). I can’t seem to make sense of it because you’d think if anyone was a candidate for solar, it would be me. I haven’t priced a ground-based system yet but I am not enthused about having that in my yard even though I have the space. The cost per kWh Solar City was proposing for the “we are your electric company” leasing thing was nearly the same that I pay to my existing electric company so it didn’t seem worth it to pursue.

- - - Updated - - -

JamesW said:
Offer $600 for the upgrade or ask to be credited for the cost of the single speed pump and buy the variable speed pump on your own.
Click to expand...

Yeah that was my plan but he firmly shot down any flexibility so I think that idea is totally out.

And before you suggest I go with another builder which would be what I would tell somebody in this situation, another pool builder in the area asked me “Why would you think you know more about the equipment than I do?” That immediately put him off of my list but the sheer ignorance there was astounding.
 
Captchaos said:
And before you suggest I go with another builder which would be what I would tell somebody in this situation, another pool builder in the area asked me “Why would you think you know more about the equipment than I do?” That immediately put him off of my list but the sheer ignorance there was astounding.
Click to expand...

Yah, they mark that stuff up so much, they're not going to give it up. Like trying to convince a realtor they should work for 3% instead of 6%. They're only worth 1 or 2, but they think they deserve 10.

Technikal, did you do the install yourself? Do you still get the full warranty?

To be completely fair, pump manufacturers and installers can make a case. Why should they warrant something, or an entire system, or an entire pool, when the owner has done some of the work, or furnished some of the equipment. If things go south, who's at fault? I get that. But marking up something 100%, or more, and charging for the install labor? That doesn't seem reasonable either.
 
I did the install myself. It was just a motor swap on an old pump, so no warranty to worry about.

On run times, our pool is surrounded by trees, so I typically run the pump longer than I otherwise could in order to keep the skimmers going. This time of year with the SWG off because it's too cold, I could probably get by with 4-6 hours a day on low from a pure filtration standpoint, but then I'd end up with tons of leaves on the bottom of the pool making a mess and forcing me to vacuum/run the cleaner more. Gotta love Live Oaks that drop their leaves 2x a year! Of course, those same trees probably knock 50% off my summer AC bill, and they are beautiful, so I won't complain too much.
 
You sound like me, trying to squeeze out as much performance as I can. I have a variable, and a controller. I have this scheme of running the filter cycle as little and as low as possible, but then programming once or twice a day a brief "toilet bowl" cycle in which I would ramp up the pump pretty high, get the water circling and the skimmer sucking pretty good, to see if I can control the surface stuff that way, without having to skim all day long. I haven't tested that out yet, though, because it's been spring here all winter and we haven't had much wind and no storms that usually muck things up for my pool. So I've gotten by on just the low speed cycle for now. Summer time is solar and SWG season, the pump is running plenty high for plenty long, so the water and surface stay pretty clean, and I can't really dial anything back without losing pool temp.

Can you use any sort of timer or automation to switch the pump from low to high and back again? Or manual only? I tried to get by with my two speed for a while, but low was too low and high was way to high, neither speed was great in terms of function or efficiency. Before I replaced it I didn't even know about adjustable RPMs on two speeds, so I don't know if mine had that or not. And I only assumed there was no way to automate the speeds before the pool guy sold me all my current setup. Of course, he wouldn't have tried to talk me out of a purchase! Oh well, I'll keep learning here at TFP and try to be better informed for the next big pool decision, whatever that might be...
 
You can automate the switching between speeds on a 2 speed pump. They make timers specifically for that, or you could use one of the motors with the timer built in.

I'm not aware of any 2 speed motors that let you adjust rpms, though. So far as I understand, the 3450/1725 rpm thing is a function of the 60hz electricity we have in the US. Maybe it's a variable speed motor with presets?
 
Technikal said:
I'm not aware of any 2 speed motors that let you adjust rpms, though.
Click to expand...

That is one thing I have noted for folks based in the US. The manufacturers don't seem to have the latest technology embedded in their pumps.

Here in Australia, variable speed pumps tend to be the norm with all new installs. It may also be due to our relatively higher electricity costs which may have more do to with it as well.

Below is a link to a common pump used DownUnder - It is a 3 speed (all 3 speeds can be user settable to whatever RPM the pump can handle) and it also features a 4th 'Overdrive' mode for priming/vacuuming etc.

Pretty much standard kit here in Aus....

Viron XT Variable Speed Pumps | AstralPool

 
Huh, I thought I read somewhere here about a user-adjustable two speed. Anyway, this is academic, for Technikal, his pump is what it is.

And come to think of it, "Variable Speed" is a bit of a misnomer. My Intelliflo 2 VST is technically just a four speed pump, with each speed user selectable. (Or eight speed if I had the better controller.) It's not variable in the sense of a variable power drill...

But maybe Technikal could make use of that 2-speed timer at some point.
 
If the variable speed pump can be set between 600 and 3450 rpm in 1 rpm increments, then it's a 2,851 speed pump.

A variable speed pump adjusts the power frequency to control rpm.

A two speed pump uses two sets of windings, a two pole set and a four pole set to allow for two speeds.
 

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