Variable-Speed Pumps: Head Of The Class by Kirstin Pires

     It's pretty unusual to hear pool builders raving about pumps instead of cursing them, but recent developments in variable-speed motors for swimming pool pumps have some early adopters convinced they have come face-to-face with the future.
     Whether it's been motivated by heightened safety concerns, the California Energy Commission's looming energy efficiency regulations, or just the innate human desire to build a better mousetrap, innovations in the design of pool pumps are giving builders options like they've never seen before. Radical energy savings, enhanced safety, longer pump life, reduced noise and increased water quality are just a few of the benefits of the next generation of pool pumps.
     Variable-speed motors have been around for a while, but the pool and spa market has only recently discovered their benefits. Leading the variable-speed way are two companies: a small California manufacturer, Ikeric, headed up by Ike Hornsby, who began marketing his variable-speed pumps about two years ago; and the category giant Pentair, which recently introduced its IntelliFlo line of pumps.
     The concept behind the variable-speed pump is deceptively simple: configure a motor that does the least amount of work necessary to get the job done. With the Ikeric pump, the installer has to figure out where that efficiency point is, as with a conventional pump. With the IntelliFlo, a complex digital component calculates the system parameters and adjusts its energy draw and work output accordingly. The installer simply enters the desired flow and the computer figures the operating point on that particular, unique system that will achieve it.
     Conventional electric motors are built to run at a specific speed that is determined by the motor's anatomy and governed by the current it receives. In the past, builders had to change other parts of the equation to fit the pump, but now the pump can adjust to fit the system and the situation.