I'm in the early stages of a pool remodel and need a little help with pump sizing. I'm contracting out new plaster and tile, but want to replace/replumb the equipment pad myself. Most of the resurfacing companies quickly bid the equipment portion of the remodel and I don't feel they'll take the time to analyze what the best option will be given the current layout and pipe size. Anyway, I'm looking to simplify the original setup and maximize efficiency however possible.
The pool & spa was built in the late 1970s and is around 16K (18K MAX). The spa does not have jets, only a blower feeding a few holes in the bench. Our plan is to abandon the blower and heater as we do not want to heat the pool or spa. We'll use the spa as a lounge area and for the spillover/waterfall feature. I want to cut all of the pipes at the equipment pad and start fresh. I'm looking for a simple setup - main pump & booster, 48 or 60 DE Filter, (2) 3 way valves and whatever check valves are needed for the spa.
Back to pump sizing... I'm stuck with 1.5" PVC for the suction and returns & 3/4" for the pressure cleaner (currently a newer 280).
(1) 1.5" suction line from the skimmer (main drain connects to skimmer)
(1) 1.5" suction line from spa drain
(1) 1.5" return line to pool (3 eyeballs)
(1) 1.5" return line to spa (1 eyeball)
Currently we run the pool with 100% pool suction and 50/50 on the pool & spa returns. Should I try to calculate what my total feet of head will be with the new layout and use a smaller single speed sized to the maximum flow rate of the 1.5" plumbing or will I benefit with a variable speed pump? We have no problem with the added expense if it will cost less to operate over the lifespan of the unit. Thanks for any and all help.
A few pics...