Skip to comments.What Size Pool Pump To Buy?
Posted on 04/07/2010 1:53:22 PM PDT by ExpatCanuck
I have a 7 year old 40K gallon inground concrete pool and the 2HP pump needs to be replaced. We typically run it 8-10 hours a day and have a DE filter and a spa. I've had someone tell me that if I buy a smaller pump (1HP for example), I can leave it running 24 hours a day and still spend the same in electricity. The advantage being that the water is constantly being moved and filtered and stays cleaner, albeit at a slower rate. Just wanted to get thoughts on this from others here.
WHAT VOLTAGE 240?
Check the energy use on the pumps. I think the newer pumps are more efficient. Buy a timer and experiment to figure out what is the minimum time. Not all problems are visible though and skin problems can be expected if you don’t get enough circulation.
Also, if you don’t get enough water flow your pool will end up a dark green.
The pool guy (who has no financial incentive whatsoever) keeps telling me how great the water movement is since I replaced the old system with a bigger pump.
This sounds like a pretty good sized pool. If you buy a 1 hp it will burn up faster. I would run it a few hours a day. I would consider a chlorine generator that generates chlorine from small amounts of salt.
Call some pool places but a 2 hp or 2.5 hp sounds correct.
You can buy a lot of electricity for the chemicals it will take to fix your pool if it gets out of whack.
The larger the pump motor, the less energy it consumes to do the same amount of work as a lower HP motor. Energy consumption is part of the total load. If the 1HP runs at 90% load, and the 2HP runs at 45% load, the 2HP will consume less energy to do the same amount of work since the current draw at the load will be less.
Volt x Amps = watts.
For keeping it as warm as possible ideally, you only want your pump on during the hottest hours of the day say from 11pm to 3pm. That way all the water circulates and gets heated by the sun.
Running it during cooler hours bleeds off the heat that’s built up, so it’s better to let it sit still.
Of course this all goes out the window if you also have a heater on your pool.
Try this site, it seems to have quite a bit of info.:
and yes this should be posted in the Pool Pump Forum.
The cost of electricity is DIRECTLY PROPORTIONAL to the amount of work being done.
If you want to move 8 thousand gallons of water/day, it will cost you roughly the same no matter the size of the motor.
Just don’t let anyone pee in the pool!
A 1 HP motor running for 24 hrs. will consume the same amount of energy as a 2 HP running for 12 hrs. Here is the calculation:
2 HP x 12 Hrs x .7457 Kw/ Hp-hr x .12 $/kw = 2.15 $/day
1 Hp x 24 x .7457 x .12 = $2.15
You mention 8-10 hrs per day vs. 24, the only savings will come due to the shorter time of operation, not due to energy consumption.
The real question is how effective are the two methods.
“Just dont let anyone pee in the pool!”
...even if it DOES make it warmer!
We have a 30K, IG, gunnite pool with 1.5 HP motor that runs all Summer (mid-May-early Sept). It’s not killing us on electricity and I think it keeps the heat more uniform and the chemicals better mixed. We also have a salt chlorine generator. Best investment we every made.
Pool pumps are sized to a 8 hour pump cycle. This is because they generally are run during the day such as not to cause noise and problems with neighbors. The rule is the water should be turned over, that is pass through the filter, once in a 24 hour period.
The system is more efficient if the water is pumped slower over a longer period. All else equal, by pumping over a 24 hour period with 1/3 third the flow rate 1/3 the power will be used.
I also have a 40K gallon pool. I use two pumps. One, 3HP is used to run the pool cleaner when I want to. The other is a two speed that I have wired for low speed at 1/3 HP. I run it during the week continually unless I want to clean the pool. It is more costly in hardware but worth it given the cost of electricity in the area I am in.
Do people really run their pump that long?
I thought a couple of hours a day was sufficient
There's actually a pool pump forum? :-)
Thanks, I'll check the link!
No, this is the perfect place. In fact, I was over at "www.PoolMaintenanceAdvice.com" this morning posting my thoughts on Obama's new health care bill and someone replied to my post and needed to know where to get pool maintenance advice. It sent him to Freerepublic.
I, myself, like to pump and filter more and chemically treat less. But I am willing to pay a price for the electricity.
You need a big’un
Hey, it was worth the laugh I got reading your response!
I think yours is a good trade off, and it seems with the newer pumps I should be able to realize some savings even with the same 2HP size.
I have a 15k/gal pool and run the pump 4-6 hrs a day. I buy a bucket of 2” chlorine tabs and a couple of bags of baking and washing soda at the supermarket, a bottle od algecide and clarifier and it lasts all season. In Memphis.
“WHAT VOLTAGE 240?”
220... 221, whatever it takes. :)
Here you go. Now you have something exciting to do tonight.
Have you checked-out the Pentair IntelliFlo Pool Pumps?
They're expensive but can really cut your energy costs. Probably pay for itself within a year or so.
Kramer: I'm freezin'! I just need to get my hot tub running. I'm waiting for my new heat pump.
George: Well what's in this giant box out in the hall?
Kramer: Uh? Oh that must be it.
George: It's huge!
Kramer: Yeah, yeah, I got the biggest one they had. It's industrial strength. 16000 BTU's.
No such forum but rules require that we have a go at serious inquiries.
The site is real and appears to have what you need and more.
Check the label on your 2hp pump for the “SF” the true hp is the rated hp multiplied by the SF number ,, it can range from 0.9 to about 1.5 ... if your 2hp pump is a SF 0.9 then you really have a 1.8 hp pump and a 1.5 hp pump with a 1.2 SF will replace it ...
With a DE filter you have a problem with dirt and debris going back into the pool after every instance the pump shuts off and restarts .. I am assuming your DE filter redeposits the DE powder on the screens automatically at startup ... with every power cycle you let MOST of your dirt go back in the pool ...That is why commercial/public pools are required to filter 24*7*365 .... you should probably get a sand filter..
I hate it when people try to misle me!
8 - 10 hrs a day is too much....IF that's your average over a year.
My rule of thumb was to buy the biggest equipment you can afford...and keep you water chemically correct.
Yes, that said, does his service provider charge for tiers and time of day? If you exceed a certain level, they bump the cost per kwh meaning overall cost of ownership might be lower with a pump that draws less. Of course, if they charge more at peak then a stronger pump that can turn the water over faster but runs off peak would be the better choice.
IF YOU GET A SMALLER MOTOR AND RUN IT 2X AS LONG U WILL USE THE SAME AMNT OF CURRENT OVER A 24 HR PERIOD;;;SORRY 4 CAPS
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.