Questions on changing to a 2 speed motor on a Hayward Super II pump

[keastman]

I am considering changing out the 2 Hp AO Smith motor( SF=1) on my Hayward Super II pool pump. The pool is in St. Augustine Fl and is not screened in. We have four large Live Oaks that surround it and this time of year it is a full time job just to keep the water a pleasant shade of brown or green from all the leaves, pollen, and calkings from the trees. I'm usually running the pump 18-24 hours a day for a month and the electric consumption is out of hand. In the summer I run it about 8 hours a day and 4 hours a day in the winter. I was hoping it would be more efficient to use a two speed pump on low 24/7 this time of year. The filter is a Hayward c1200 cartridge (120sq ft ?) I feel this pool is over pumped and underfiltered. The pool is 22900 gallons with a qwik clean II in floor cleaning system which does little with all the tree debris, also there is a spa that is approx 3-4' above the pool and a heat pump. At present the heat pump is broke and will not be replaced, and the spa isn't used. One other strange thing about this set up is that if I try to isolate either the main drains or the skimmer on the three way valve on the return, the pump will get air in the basket, but it does not as long as I have the valve set to both the main drains and the skimmer. The bubbles almost seem like cavitation from too much suction.

There is also a SWG (Jandy Aquapure) that is split off the main return on a separate 1 1/2" line that has it's return in the bottom of the skimmer housing with a reduction nozzle at the return in the skimmer so that it comes out as a strong stream. The return lines for the skimmer and drains are 2" and the equipment is about 45' from the pool at close to pool water level or a bit lower.

My question is, could I replace the 2 hp motor with a 2 sp 1 1/2 hp motor? I believe I read that I'd also have to replace the impeller if I downsized. Would I gain much electrical savings by down sizing the pump motor to justify the added expense of a new impeller and possibly diffuser? Or, would I be better off just getting a 2 sp 2hp motor? I'm also wondering how the SWG would fair on low speed especially since it is split off on it's own line from the main return.

Sorry for the long post. Thanks for any input on this problem you folks can give me. I've got pictures I can post of the set up but can't figure out how.

Thanks, Kevin

[aylad]

Hi Kevin,

If you'll email your pics to poolforum@gmail.com, Ben can post them up for you. I can't answer your pump questions, but I know there are others here who can--just give it a few days because the traffic is just beginning to pick up around here. I'm sure Ben, Poconos, Waste, Mark, and some of the other equipment gurus around here will be by soon!

[keastman]

thanks, I'll do that.

[mas985]

WIth both a in-floor system and a spa, reducing the HP of the pump would reduce the performance of both. So unless you are willing to give those up entirely, I would keep the same size pump. Anyway most of your energy savings will come running on low speed so downsizing the pump isn't nearly as important as the low speed. Low speed will save about 50% in energy while each 1/2 HP drop in pump size will save about 10% more including turnover changes. Doing both will save more but again, you will sacrifice the spa and in-floor.

Also, the SWG should work fine on low speed of any size pump.

[PoolDoc]

Overall layout:



Valves in train-wreck orientation!




Dangerous wiring:




Hayward cartridge filter:




Collapsed filter cartridge:




Step-down to 1.5"??

[PoolDoc]

OK. Here's stuff I've noticed so far.

1. Cartridge filters are seriously over-rated in residential applications. There's nothing magical about a residential pool that suddenly transforms a 45gpm (0.375 gpm/sft) commercial filter into a 120 gpm residential filter. Your filter cartridge is shot . . . and shows the pleat collapse typical of excessive flow and pressure.


2. Your pump was probably sized to run the in-floor cleaners and span. In-floor cleaning systems require large overpressure value to operate, and consequently are MASSIVELY inefficient. They cost 10,000's of pool owners $100's or even $1,000's annual in excess electrical costs.


3. Your piping is a typical pool guy hydraulic mess! I spent a couple of hours on the phone today, trying to get through to the Pentair engineers. I failed, but did confirm from the tech support guys that putting a 3-way valve in train-wreck orientation (water entering from BOTH sides of the T, and leaving via the side outlet) is a SERIOUS piping error. These guys assume -- they don't have much field experience -- that no one would be so dumb as to pipe a pool that way!

And, because it's assumed no one would install a 3-way valve in such a brain-dead configuration, none of the companies with 3-way valves have published head loss curves for their valves in that configuration!

Your piping has, not one, but TWO train-wrecked 3-way valves. If the spa is off, only one train-wreck (the skimmer + main drain) valve is 'live', but there's no way you can feed a 2HP Hayward Super II that way, and not have suction problems.


4. I can't make out exactly what's happening behind the filter -- I assume that's where the piping is looped to the heat pump? Regardless, I'd need a picture looking DOWN behind the filter, and another looking down on the return (pressure) side automatic valve, to work out what's going on.


5. If you were to
+ take the spa and the floor inlets out of the picture entirely,
(water can flow out of the floor inlets, but any restricters would need to be removed, and the cleaning heads would NOT actuate.)
+ replace the C1200 cartridge,
+ repipe the SWCG to straight flow through for ONE of the returns

THEN you could
+ replace your motor with a 1HP 2speed motor, like the AO Smith B975 motor on this page:

http://www.a1poolparts.com/-strse-Mo...Categories.bok

+ replace your pump seal, and impeller with the correct seal and a 1 HP impeller
+ install a 1HP motor rated DPDT toggle switch on the wall behind the pump

AND THEN
+ run the pump on low most of the time, probably with the MD closed, and the skimmer open.

Instead of running a 2 HP load, you'll would be running a 0.2HP load, with 30% or more of your original circulation. With your cartridge clean, and your piping fixed up, you are likely to get near the optimal filter rate for that C1200 (about 40 GPM), but for 10% of your original electrical costs.

[waterbear]

The Hayward filter is very undersized for this pool (and I have a guess as to who the builder might be since I have seen several pools that have been undersized on this filter). I suspect that the filter requires cleaning every week or so. particularly with the seasonal pollen problem here and the oaks. A pressure side cleaner or a robot would do a better job of keeping this pool clean than an in floor system. They ar basically worthless for the type of stuff falling into this pool!

The two speed pump would be an excellent idea and keep it 2 hp since you probably need that for the spa jets but I would also consider upgrading the filter to something larger such a a Pentair clean and clear plus for a pool that size.

[PoolDoc]

Kevin;

After reading over Waterbear's post, I realized you need to make some decisions, and let us respond to them:

1. Will the heat pump ever be brought back online? (If not, it would be best to delete that piping.)

2. Will you ever use the spa? (If not, you need to be able to fill and drain the spa, for cleaning purposes, but you do not need to size the pump to service the spa.)

3. Will you ever try to use the in-floor cleaning again? (My guess is, on this score, you should not: they don't ever seem to work very well, they are energy -- and thus, electricity HOGS -- and with leaf and grass debris they seem less effective than with dirt and dust. Again, you do not have to size for them, if you are permanently abandoning them.)

If you are abandoning the heat pump, the spa and the in-floor system, you don't need the 2HP pump. If you want to keep either the spa or in-floor system, you probably do. With the heat pump, if you want to keep it, you may need to convert the piping from side stream to full flow, if you use a 1HP pump.

If you want to abandon it all, for now, but retain the ability to crank it up later, you might want to look at a Pentair Intelliflo, which is a 2HP Whisperflo pump that has fully variable speeds. It won't be quite as efficient as a 1HP Whisperflo, but it will probably be as efficient as a 1HP Super II . . . and you won't have to install a timer, since that's built in.

The down side, of course, is that it is expensive. And, you should repipe so that you can get it up off the ground -- it will last much longer that way.

[waterbear]

Just to clarify, I am in St. Augustine also so I am very familiar wit the conditions and problems here. When the pollen is bad everyone seems to think they have mustard algae and uncovered pools get a lot of debris that in floor systems just can't keep up with, suction side cleaners tend to choke on, but pressure side cleaners and robots do a better job with.

[PoolDoc]

Thanks, Waterbear.

It's not often the PoolForum can help offer LOCAL help and knowledge!