Drive upgrade boosts chiller performance
Retrofitting variable-speed drives to centrifugal chillers at the London headquarters of Citi to reduce energy consumption has exceeded expectations. Carrier upgraded two of its AquaEdge 19XR5 chillers with variable-speed drives based on its Greenspeed intelligence. During the first three months of operation, savings were £33 966, exceeding the estimated £126 000 per year. The savings are achieved by controlling the speed of the compressor in response to cooling demand.
This customised solution will also reduce service costs and extend the working life of the chillers by providing soft start and soft stop.
The project was carried out in two stages.
The first stage was to install Greenspeed intelligence on one chiller. The reduced energy consumption enabled Carrier to make a supported case for upgrading the other chiller, which was accepted by the client.
Because of height limitations in the plant room, Carrier co-ordinated the dismantling of the large variable-speed drives into three sections, moved them into position and re-assembled them.
Following the success of this project, Carrier has won orders for several similar upgrade projects on centrifugal chillers serving multi-storey commercial buildings in London and elsewhere in the UK.