NFT's Supa-Stelth pump's SBV operation allows it to deliver 67 litres per watt hour at low RPMs.
NFT's Supa-Stelth pump's SBV operation allows it to deliver 67 litres per watt hour at low RPMs.

The US Department of Energy (DOE) Conservation Standards for Dedicated-Purpose Pool Pumps has set a deadline for variable speed pumps, rather than fixed speed pumps, to be mandatory in pools and spas by July 2021.

As the deadline approaches, pump manufacturers and the pool and spa industry are working hard towards compliance with DP3 as the ruling is known.

Australian pump technology specialist, New Fluid Technology (NFT Australia) has been working on a new variable speed pool pump which, the company says, cuts energy consumption by between a half and one third at normal backwash and priming speeds of 3600 RPM and delivers 67 litres per watt hour at low RPMs, conserving energy in line with DOE regulations.

The Supa-Stelth pump works on the Solid Body Vorticity (SBV) principle of operation.  The impeller is, in effect, a solid body of water that cannot change its shape because of the speed it is repeatedly travelling through a small vortex-shaping surface or window.

Its unusual design means it has no impeller blade tips which eliminates any chance of cavitation at standard and higher than standard RPMs.  This allows the use of both smaller impellers and smaller pumps which can still operate at high levels of efficiency because smaller impellers actually allow greater acceleration of fluid.