500 tonnes of CO2 per year is expected to be saved at Kingston Heights, a new sustainable housing development in south west London, thanks to its use of water from the River Thames to supply heating, hot water and cooling. When completed, the estate will be heated and cooled by an open water heat pump system, with virtually no on-site carbon emissions. When it came to choosing a drive solution for this highly-efficient system, automation provider Electraspec specified WEG’s variables speed drives (VSD). The company installed four highly-efficient CFW11 VSDs within the control panel that will operate the heat pumps.
Kingston Heights is a £70m development in Kingston-Upon-Thames that will comprise 137 residential units, including 81 private apartments, 56 affordable homes and a 142 bedroom hotel. The development relies on a sustainable open water heat pump system, which provides heating, hot water and cooling to the buildings.
The system works by recovering the solar energy which is naturally stored in the Thames, with up to 150l of water a second being extracted after passing through a two-stage filtration process. The water then passes through heat exchangers to harvest the low grade heat before being returned to the river with a temperature change of no more than +/- 3°C. The process is totally environmentally-friendly and produces zero on-site carbon emissions, in contrast to the estimated 500 tonnes of CO2 that would otherwise be emitted by a combustion-based system, and is expected to reduce energy bills on the development by around 16% per annum.
To reach these ambitious energy saving targets a drive solution was needed that ensured reliability while offering ease-of-use. Thus, the company turned to automation company Electraspec, who designed a bespoke pumping system control panel, equipped with two 18.5 kW and two 30 kW CFW11 drives. “Kingston Heights is an ambitious and pioneering project, so we were keen on providing WEG’s VSDs because of their efficiency, reliability and ease-of-use,” comments Eric Knight of Electraspec. “By effectively controlling the flow according to temperature, WEG VSDs will contribute to boosting the pump system’s energy efficiency and will play a key role in helping Kingston Heights achieve its ambitious energy saving targets”.
WEG’s CFW11 drives are designed to ensure a precise control of pressure, flow and temperature while optimising power consumption through speed control, particularly in applications such a pump control systems. With intelligent thermal management features providing automatic cooling to the internal components, the CFW11 also ensures reliable operation.
Additionally, the drive offers a user friendly HMI with large character graphics, enabling quick and easy installation. The product also features the SoftPLC function that attributes PLC functions to the inverter and can be operated remotely. This function contributes to reducing maintenance and associated costs thus enhancing productivity and efficiency. “We are able to control the system from our laptops and are immediately alerted if there is a problem,” commented Eric. “For example, this function enables us to operate speed and run commands without having to be physically on site”.
Thanks to its Multi-pump Control feature, the CFW11 is able to control up to five pumps and keep constant pressure regardless of flow fluctuations. The VSD also monitors suction pressure and tank levels, alternating the pumps according to their operating time, and ensuring uniform wear and tear for motors and pumps.