new pump needed

[bomberchamp]

I have a fiberglass inground pool. It's 20,000 gals and needs new motor. I would like to upgrade to something more efficient. I have 1 1/2 inch lines coming and going and the only intake I have is the skimmer with two discharge outlets in the shallow end. I have a 175 cartridge filter that does an ok job. My question is do I need a vs pump or will a 2 speed suffice? I run pump about 8 hrs a day in summer and 6 in winter. I currrently have a hayward 1 hp rs1000 pump and motor that locked up. Power is at .11 per kw.
Any advice would be appreciated

[PoolDoc]

OK:
=> 20,000 gallons
=> 1.5" pump return from skimmer;
=> (2) 1.5" pool returns from filter

Your maximum effective flow rate is set by your single skimmer return -- you do NOT want to exceed 6 fps (ft per second) flow rate if possible, because pumping rapidly becomes in efficient as you do so. (page 47 of the Charlotte Plastic Pipe tech manual) This limits you to 35 - 40 GPM. That's a little low for a 20K pool -- 42 GPM is 8 hour turnover (= a volume equivalent to your pools volume goes through the filter in 8 hours, but that does NOT mean that 100% of your pool water is filtered in 8 hours!)

So, your looking for 35 GPM, but need better water quality than you'd get with a sand filter on 9 hour turn-over.

Assuming you have no other equipment, you could get excellent energy efficiency with a 2 speed 3/4 HP Whisperflo
model WFDS-3 for about $570 + shipping, OR a IntelliFlo Variable Speed . . . which is just a 3HP Whisperflo wet-end with a variable speed motor. Considering that you'd have to install a special timer for the Whisperflo, the Intelliflo might be a better idea.

I don't know what a "175 cartridge" filter is, so I can't comment on whether that's a suitable filter, or not.

However, if you wanted optimal water quality, something like a Hayward ProGrid 60 or even 72 would give you that:
http://www.a1poolparts.com/-strse-25...ter/Detail.bok

If you select a cartridge filter (other than the one you have now) remember to check on replacement cartridge cost BEFORE you buy the filters. Some modern cartridge filters, like the StaRite System3 have EXTREMELY expensive replacement cartridges, that are also very difficult to handle when wet and dirty.

[mas985]

The RS1000 has about the same flow rate as the Whisperflo 3/4 HP on the same plumbing so that would be a good match. However, if you want to save some money you could also just replace the RS1000 motor with a two speed motor.

[bomberchamp]

Thanks for the replies. I went back and calculated the pool capacity and I think it is actually 16,500. It is a rectangle 30 x 12. It is 8 feet deep and 4 in the shallow does this figure jive? The Whisperflo wfds 26 is 115 olds and the pump I have is 230 I believe. If this is the case I should be able to just use one leg on one of the breakers and hook the other up to common right?
Going back to the vs compared to the 2 speed I found out that with the power company rebate the out the door price for a vs would be around 920.00. I found the wfds 26 for around 570.00. Which way would you go if it was yours to do, and how long can I realisticly expect these pumps to last?

[PoolDoc]

+ Pool volume: 12' x 30' x 5.5' avg depth x 7.48 gal/cft = 14,800 gallon => round down to 14,500, since you will not run the pool at overflow!
+ Whisperflo wfds-26 is has a 230V motor; I don't know what "115 olds" is, but I'm guessing you are saying something about the voltage.

If this is the case I should be able to just use one leg on one of the breakers and hook the other up to common right?

I'm going to be blunt . . . because when you mix electricity with pools in the wrong way, you KILL people. Your question tells me you SHOULD NOT DO THE WIRING YOURSELF! Period. End of story. You can watch and learn, but get someone who knows what they are doing!

Not sure where you are getting your prices, but a Pentair Intelliflo (vfd drive & motor on a 3HP Whisperflo front end) can be had for ~890 + shipping:
http://www.a1poolparts.com/-strse-34...tra/Detail.bok

From the same company, a 2-speed Whisperflo can be had for $570 to $740, but keep in mind you'll have to have a special time clock (DPDT) with the Whisperflo, but not with the Intelliflo.
http://www.a1poolparts.com/-strse-61...ump/Detail.bok


It's quite common for pool pumps from the better companies (like Pentair) to last 10 years . . . BUT make an effort to get your new pumps 2 - 4" ABOVE ground level. It will last longer if you do.

[mas985]

The WFDS-26 is a 1.5 HP up rated pump and it would be too big for your pool. The pump I was suggesting was the WFDS-24 or WFDS-3 which are really the same pump. If you want a 230v pump, I would suggest the Superflo 1 HP up rated pump. It is a smaller pump than the Whisperflo but I don't think you need a big pump anyway.

At $0.11/kwh, it will take a long time to make up the difference in price. I estimate it will take about 160 months of one turnover/day in order for the Intelliflo to start being more cost effective than the Whisperflo so the Whisperflo will probably have a lower lifetime cost.