Power Bill for running Pool Pump 24x7? Pump too big?

[mas985]

I have yet to see a web site (Pentair's included) which fairly characterizes the savings of a two speed or VS pump.

Also, although the cost savings can be significant with a two speed pump, there are some downsides as well. For one, skimming just doesn't seem to work as well at lower flow rates and for some setups. Lower flow rates can result in less debris in the skimmer and more on the pool floor even with a 2x increase in run time. In some cases, the flow rate is not even sufficient to lower the weir door so the flow basically goes through the gaps in the door. So you may end up running the pool cleaner longer to make up for the some of the cleaning deficiencies. So I usually caution people that they MAY see 50% savings but results will and do vary.

 

[linen]

Not trying to be a shill for the pump industry, I think 2-speed pumps are often the better choice for some swg users that have long run times(I am a example of this). My swg run time right now is 8 hours/day and I know my pool doesn't need that much time on high.

I also wonder if for many people who get a lot of debris, leaves, etc., if skimming on low for longer, assuming they have enough flow to move the weir and create that high surface flow, might be better off then skimming on high for shorter. I think my situation fits this category. Other pools might need the velocity of high speed to keep the pool clean.

IMO, if your pump/filter is well sized for your pool, you have good circulation, do not have a swg, and you do not have water features...then a properly sized 1-speed running for just a few hours might be the best choice. There sure is not one right answer that meets all situations.

 

[jblizzle]

The key to that statement is a well sized pump/filter combo. That seems to be a rarity.

Posted from my Droid with Tapatalk ... sorry if my response is short

 

[UnderWaterVanya]

Thanks all. At least I have ammo to noodle on now.

Oh and Linen's right - I'm crazy...

 

[UnderWaterVanya]

Re: Power Bill for running Pool Pump?

I have dual suction on EDIT: What I think is 2" pipe (I haven't measured it yet - but the 2" backwash hose fits perfectly) and a pair of returns on 2" pipe but one return goes through a booster pump and has a much smaller hose. The other return is shared with two outlets on the stairs and there is a smaller pipe feeding a slide. The filter is a Hayward S210T which has a flow rate of 44GPM for backwash and filtering. My understanding is that a 2" pipe is good up to 73 GPM. My suction side valves are partially closed and if they are opened all the way I get air in the system - I assumed initially that this was due to faulty valves or other problems but I wonder now.

1.5 HP on a 13,500 gallon system with my filter seems like overkill... but I don't know enough to know any better.

The system also includes a booster pump for a Polaris 380.
Filter pressure runs around 10-10.5 PSI freshly backwashed.

Just based on this description, I estimate that the pump is producing around 69 GPM @ 35' of head and 1400 watts. The 1.5 HP up rated Superpump that you have is actually a fairly small pump and smaller than some pumps with smaller label HP.

But also, running 24x7 is rarely if ever required. Under normal circumstances, most pools can get away with less than a turnover per day. I am currently running only a 1/2 turn per day and the pool is kept fairly clean. So a much simpler and cheaper solution would be run the pump 3 hours per day and see if that is enough to keep it clean. Just make sure that you get enough chlorine in the pool.

Mark - the info I gave you was faulty. I was reviewing my old threads and realized I said 2" pipe but I have since figured out it is 1.5" pipe. How does this change your calculations? I also have dropped my normal run time to around 8 hours which was working great until an accident caused us to fail to add bleach for 2 days!

 

[mas985]

It is probably around the same wattage ~1400 watts. One the problems is that Hayward did not measure their pumps for plumbing Curve-C so there are only two points that I can extrapolate from when estimating operating points and wattage. I believe that the operating point is close to the best efficiency point and 2" plumbing is on the right side and 1.5" is on the left side so both are close to the maximum power consumption just on opposite sides of the curve. However, if you want a more accurate number, I would suggest using your house power meter.

 

[UnderWaterVanya]

It is probably around the same wattage ~1400 watts. One the problems is that Hayward did not measure their pumps for plumbing Curve-C so there are only two points that I can extrapolate from when estimating operating points and wattage. I believe that the operating point is close to the best efficiency point and 2" plumbing is on the right side and 1.5" is on the left side so both are close to the maximum power consumption just on opposite sides of the curve. However, if you want a more accurate number, I would suggest using your house power meter.

Thanks - is there an special way to use that meter to do this? I assume - look at the meter for x period of time with pump off and use held constant in the house; then do it again with pump on?

Ugh - sounds like the pump is poorly sized to the pool but this isn't a big deal from a cost perspective - right? If in the future the motor dies - is it worth trying to replace with something different or leaving it alone? The filter (Hayward S210T) is also undersized for my 13,500 gallon pool from what I understand. What do you estimate the GPM to be based on the new info?

Based on this info if my cost per KW/h was $0.10 then 8 hours a day would cost about $33/month which isn't bad. 24 hours a day would cost 3x that or roughly $99/month. I can check on the meter to see if I can verify the use but that seems close enough for me.

 

[mas985]

Thanks - is there an special way to use that meter to do this? I assume - look at the meter for x period of time with pump off and use held constant in the house; then do it again with pump on?
YES

Ugh - sounds like the pump is poorly sized to the pool but this isn't a big deal from a cost perspective - right? If in the future the motor dies - is it worth trying to replace with something different or leaving it alone? The filter (Hayward S210T) is also undersized for my 13,500 gallon pool from what I understand. What do you estimate the GPM to be based on the new info?
Flow rate should be around 59 GPM

Based on this info if my cost per KW/h was $0.10 then 8 hours a day would cost about $33/month which isn't bad. 24 hours a day would cost 3x that or roughly $99/month. I can check on the meter to see if I can verify the use but that seems close enough for me.

There is a very good chance you could get away with much less run time. At the very most, you should not need more than 4 hours which would save you $50/month.

 

[UnderWaterVanya]

Thanks - is there an special way to use that meter to do this? I assume - look at the meter for x period of time with pump off and use held constant in the house; then do it again with pump on?
YES

Ugh - sounds like the pump is poorly sized to the pool but this isn't a big deal from a cost perspective - right? If in the future the motor dies - is it worth trying to replace with something different or leaving it alone? The filter (Hayward S210T) is also undersized for my 13,500 gallon pool from what I understand. What do you estimate the GPM to be based on the new info?
Flow rate should be around 59 GPM

Based on this info if my cost per KW/h was $0.10 then 8 hours a day would cost about $33/month which isn't bad. 24 hours a day would cost 3x that or roughly $99/month. I can check on the meter to see if I can verify the use but that seems close enough for me.

There is a very good chance you could get away with much less run time. At the very most, you should not need more than 4 hours which would save you $50/month.

Now I'm confused. Am I doing the math wrong? My expected run time is at most 8 hours a day which I calculated to be $33/month.

Math
1400 watts = 1.4KW
1KW for 1 Hour = 1KW/h
8 hours * 1.4KW * $0.10 / KW/h = $1.12 / day
30 days / month * $1.12 / day = $33.60 / day

How do I save $50/month when I'm only seeing about $33.60 outgoing. Rates are actually slightly under $0.10 per KW/h.

EDIT: BTW - Thank you for your answers to my questions.

 

[mas985]

I misread your post stating $99 but I now see that was for 24 hours. So at four hours that would be about a $15 savings per month.

 

[UnderWaterVanya]

I misread your post stating $99 but I now see that was for 24 hours. So at four hours that would be about a $15 savings per month.

Phew! OK - I thought I had lost my mind! Thanks a bundle!

Another clarification: You stated 59GPM for my setup - however with only 1.5" pipes I thought I had seen where a max flow limit was less than this.

Details: I have dual suction inputs (each 1.5") that join to a single 1.5" before the pump and then outflow from the pump is a single 1.5" to filter (S210T). From the filter a single 1.5" splits into three lines a 1.5" that splits at the pool to dual returns and a 1" booster connected return (1.5" in the ground) and a 1" or 3/4" line for the slide (rarely on).

 

[jblizzle]

After writing all this ... Not sure this post really adds anything ... so feel free to skip it

There are flow recommendations for pipe size based on water velocity I think, but not really a "max" as far as pool plumbing is concerned.

From the sound of your setup the "bottle neck" is likely your pad plumbing. My setup is very similar with two 1.5" pipe joining at the pump, but I just plumbed a 2" from the valve to the pump. I also used 2" pipe for everything on the pad which then splits into multiple 1.5" pipes heading back to the pool. You could likely decrease your pressure and increase the flow rate by using 2" pipe anywhere you only have one pipe ... although the minor increase may not be worth the hassle.

Although re-reading, sounds like you normally only have one 1.5" pipe return to the pool in use so that would limit things as well.

 

[UnderWaterVanya]

After writing all this ... Not sure this post really adds anything ... so feel free to skip it

There are flow recommendations for pipe size based on water velocity I think, but not really a "max" as far as pool plumbing is concerned.

From the sound of your setup the "bottle neck" is likely your pad plumbing. My setup is very similar with two 1.5" pipe joining at the pump, but I just plumbed a 2" from the valve to the pump. I also used 2" pipe for everything on the pad which then splits into multiple 1.5" pipes heading back to the pool. You could likely decrease your pressure and increase the flow rate by using 2" pipe anywhere you only have one pipe ... although the minor increase may not be worth the hassle.

Although re-reading, sounds like you normally only have one 1.5" pipe return to the pool in use so that would limit things as well.

Here are some diagrams of the plumbing now:
[attachment=2:1b31jm05]current pad plumbing.jpg[/attachment:1b31jm05]

One potential future - with 3 valves:
[attachment=1:1b31jm05]Future-A pad plumbing.jpg[/attachment:1b31jm05]

Another using only 2 valves:
[attachment=0:1b31jm05]Future B pad plumbing.jpg[/attachment:1b31jm05]

 

[UnderWaterVanya]

A lot of glued stuff on my pad - thinking this method may be needed to salvage the existing elbows and things to keep from making too many changes:

[youtube:3m6v8jc8]JCMQ6OA84OA[/youtube:3m6v8jc8]

Is there an easier way?

 

[UnderWaterVanya]

After looking further at the equipment - I'm not sure 2" pipe would fit the pump or filter.

 

[mas985]

Just use reduction fittings. You will be better off with 2" plumbing even though the filter and pump are 1.5". Reducing the size at the connection is not a big deal and you will get most of the benefits of the larger plumbing.

 

[UnderWaterVanya]

Just use reduction fittings. You will be better off with 2" plumbing even though the filter and pump are 1.5". Reducing the size at the connection is not a big deal and you will get most of the benefits of the larger plumbing.

Thanks! I didn't know that. SO does my "Future 3 Valve" plan make sense or do you see other ways to improve it? Granted I still have to work out the actual pad placement of all of those valves and changes.

 

[UnderWaterVanya]

While we are on the subject of changes - where do I find the filter sizing chart? I have seen one here somewhere.

I have a filter that is considered undersized (S210T) but I can't recall how much undersized it is. I have no plans to change it as it is working well for me. However I did pick up a cheap Waterway Pro-Clean 175 square foot cartridge filter (unused) for $20 on Craigslist as a spare filter in case anything should go wrong with this system. There is no cartridge included (about $85 online). I think I read this too is undersized by TFP recommendations but is it as close as what I have? For $20 I felt hard pressed to not pick it up.

 

[jblizzle]

I was a little confused on the "new" drawings. Are there ball valves and check valves that are not pictured? For example I see no way to regulate flow to the slide. And I think there will have to be a check valve after the booster pump.

 

[UnderWaterVanya]

I was a little confused on the "new" drawings. Are there ball valves and check valves that are not pictured? For example I see no way to regulate flow to the slide. And I think there will have to be a check valve after the booster pump.

I'm new to this. Today there is a ball valve at the slide itself - I did not plan to change that. I have no idea if there is a check valve in the current setup - is there something about the new setup that would require one? I guess I can see (but not fully understand) that when the booster is ON if the mixing valve is not 100% selected to the booster some of the pressure directed into that return could push back towards the other returns - is that the concern?

How could I modify this to make it better and avoid this?