Energy costs take a dive at swimming pools in Liverpool
A swimming pool in Liverpool is using over a third less energy to drive filtration pumps following the installation of ABB variable-speed drives, which have also been installed in air-handling units. The work for Liverpool City Council followed an independent energy-conservation report which recommended ABB variable-speed drives. The success of this project led to variable-speed drives being installed at four other council-run pools.
ABB authorised value provider Central Group investigated the pumping set up at the first swimming pool. The two filtration pumps were originally run as duty/standby. Pumping rates were increased as more people entered the pool. Central suggested that running the pumps in parallel would reduce energy use.
Gianfranco Colangeli of Central said, ‘At first the council was sceptical of the proposed scheme. We suggested a trial to prove that it could work, and they agreed.’
The energy use of the previous pumps was logged before two new ABB drives were installed. Central predicted a 10 to 15% energy saving, but 35% was achieved, with a payback of around six months. There was no change in water flow or pressure.
Low-occupancy switches were later installed to run the motors at even speeds when only a few people are using the pool or it is closed. Gianfranco Colangeli said, ‘We had budgeted for 45 Hz, but we can go as low as 30 Hz.’
Over 20 drives have now been installed at five sites ranging from 7.5 to 18 kW. They have also been installed in air-handling units. Energy-cost savings are £60 000 a year, with a payback of around two years.