With an existing 1HP pump on an old pool you need to consider one thing first. What size is the suction line? I'm guessing 1.5". Also what is the return line size?. As far as most energy efficient, those things will determine your best step.

If on 1.5, I'd say you're best bet is the WhisperFlo but in a 1HP 2-speed version. With 35k, you are pushing the limits of a one unit IntelliFlo. The IntelliFlo still is your most efficient pump but I would not recommend it on 1.5" with this pool.

I see absolutely no reason to install any single speed pump anywhere these days. You need to look forward to energy savings even if they are only in the 30% range that 2-speed offers.

A two speed pump will offer the noise level you want when on low speed. You will need to have the pump and the 2-speed clock to effectively get the marginal savings of a 2-speed.

Many thanks, Repair Guy! Yes, the lines are 1.5". The Los Angeles DWP Rebate Program lists two different Whisperflow 1 H.P., 2-Speed pumps: (#WFDS-4 and #WFDS-24). Which of these would you recommend? Also, should I get another D.E. filter to replace the old or a different type of filter? Please let me know. Thanks!!!

Pump trickery on the labels that is now illegal by CA Title 20. All motors are rated in TBHP or total brake horsepower. That number is the nameplate HP x a service factor or SF. Both are on the label for ID on older models manufactured before 2007.

Motors are "uprate" or "full-rate". Full rate has a larger service factor and uprate has a lower one.

Now look at what you are looking at.

The WFDS4 is commonly known as a 1HP pump. The WFDS24 is also a 1HP pump. for this line of pumps, the commonly used models are the WFDSx, not the WFDS2x. The 2 makes reference to the uprate or lower service factor.

If you buy a WFDS-4, it is a 1HP pump with a higher service factor, in this case 1.65 for a total HP of 1.65.

If you buy a WFDS-24, it is a 1HP pump with a lower service factor, in this case 1.10 for a total HP of 1.25.

The WFDS-24 is a smaller pump than the WFDS-4. You need to evaluate the horsepower you need and then make the choice. In either case, make the decision based on total HP.

The match for the WFDS-4 is the WFDS-26. The 4 is sold as a 1HP the 26 is sold as a 1.5HP. Builders love to sell the 2HP pump and then pop in a 1.5 as it is "2HP in theory". Service guys make many mistakes with this and usually oversize a pool when replacing older units. you need to evaluate TBHP.

You can cut out that SWIM RITE and get about $25 for the scrap stainless. That is what I'd do. That's a whole other topic. I like the new QUAD DE but the Clean and Clear Plus is good too.

Wow - thanks for the clarification! Will evaluate TBHP as per your suggestion. Recycling the SWIM RITE is a great idea, too! Thank you, and I'll check into the Quad DE and Clean and Clear Plus filters.

arcturus-

Agree with repair guy on the 2 speed recommendation. Although I would not downplay the performance benefit with the 2 speed as much as he did. The 2 speed on low speed should only use about 30% of the power that your 1HP single speed is using today. That is a 70% savings in power!

If, however, you have some extra c-bills in your pocket and want to improve efficiency another 10% over the 2 speed on low speed, the Intelliflo will do this. Just keep the flow below 80 gpm with the Intelliflo for 2 reasons: 1) your 1.5" pipe will start causing other problems due to high pipe velocity and 2) the Intelliflo is not very efficient beyond 80 gpm.

Hope this helps!

Thank you, trhought! I really do want to get the best value for my c-bills and yours is very good advise!!! This forum is truly a great resource for reviewing products from multiple viewpoints - so glad I found it!!!

"The 2 speed on low speed should only use about 30% of the power that your 1HP single speed is using today. That is a 70% savings in power!"

May want to recheck that...It's backwards. It is universally known that two speed saves in the 30-35% range on a good day. If it saved 70% there would be no need for variable. Try "uses 70% OF the power" that high speed would use.

RG-

I stand corrected....a 1 speed 1HP pump runs at 1840 watts and a 2 speed 1HP pump runs at 690 watts at low speed. So the 2 speed uses 38% of the power of the 1 speed for a savings of 62% in power consumed. Sorry for the 8% error. Still a significant savings in my book and pretty darn close to the power savings with an Intelliflo at low speed!

I printed the Product Specifications page for the Pentair Quad D.E. and Clean & Clear Plus filters and am worried about the high gpm flow rates that are listed (which are all above 80 gpm).
"Just keep the flow below 80 gpm with the Intelliflo for 2 reasons: 1) your 1.5" pipe will start causing other problems due to high pipe velocity and 2) the Intelliflo is not very efficient beyond 80 gpm." trhought
The lowest flow rate listed for the Quad D.E. is 120 gpm for 60 sq.ft. filtration area for 8 hours with 57,600 gallon turnover capacity. The lowest flow rate for the Clean & Clear Plus residential is 90 gpm for 240 sq. ft. filtration area for 8 hours with 43,200 gallon turnover capacity. My pool only has 35,000 gallons so I'm not sure if these filters are going to be "too much" for what I have. Most importantly, I don't want to have problems with the 1.5" pipes due to the high velocity. Please help!!!

arcturus-

Good question on flow ratings for the filters. The flow ratings are only listed to help size the filter for the size of the pump. If the filter is too small for the pump, there will be problems with the pressure drop being too high across the filter which reduces filter effectiveness and causes higher pump power because the pump has to work harder and not very efficiently.

The larger the filter area, the better because the larger surface area allows lower pressure drops across the filter which tranlates to better filter performance and better pump efficiency.

Here's a link to a .pdf that makes recommendations for plumbing size, pump size and filter sizes for different size pools. I'm not promoting Jandy in any way and only include this because it is easy to understand and can be used to help make equipment selections from any manufacturer. It does a nice job of boiling down the physics behind hydraulics and making simple pump/filter/pipe size recommendations for optimum system performance and efficiency all on 1 piece of paper! Quite an accomplishment in my opinion.

Hope this helps!

Here is a link that might be useful: Equipment Sizing Guide

That was a great guide, trhought! I have printed it out and added it to my ever-growing stack of reference material. Having a companion chart that lists the key components together (pipes, filter, and pump) is a really wonderful asset in making an informed decision about which products to buy!!! Many, many thanks!!!!!!!!!!