Time to replace the pump on my pool; the old one is screeching at me.
I have a 28k gal pool with solar heater (panels are on a shed, 5-8 ft above water level) and suction side vacuum (Hayward pool vac ultra). Filter is Hayward DE 60ft2 and I have a salt water chlorine generator. 2" plumbing and no spa or water features.
I don't know the total dynamic head because I don't have a vacuum gage. Pressure on the filter runs about 20 psi with new media.
I live in Northern California where power is very expensive (36c kwh peak!!) and I need the solar all summer because of the cool nights.
Existing pump is Hayward Super2 3020 with 2 HP pump wired to 230v. I have no reason to believe it was sized correctly at 2 HP; it was there when I bought the house.
I would like to save on energy costs. I am considering dropping the pump to a single speed 1.5hp or a variable speed. I worry about driving the vacuum effectively (we get a lot of leaves and I fight algae) and the solar heater. New CA code requires variable speed pumps, but retros are grandfathered in (for now) and I plan to do the work myself, so I can go single speed.
Some shops told me the 2 speed is a waste of money because it won't drive the filter and it isn't compatible with the solar. They said I won't see any savings. For my application, is 2 speed all hype? Of course, that brings the question of what good is a code that requires variable speed pumps when so many pools have solar heaters...other than a regulation gone wrong??
What should I be looking at? Single speed 2 hp? Change impeller and diffuser and go with 1.5hp? 2 speed? What are your experiences with pump sizing and dual speed? What should I be aware of before I buy a new motor or pump?