FCU upgrade reduces energy use by 75%
Energy-cost savings of £54 000 a year are expected following the upgrading of fan-coil units in the headquarters building of a multi-national professional-services firm in London. The upgrade involved replacing AC motors that were coming to the end of their life with high-efficiency EC fans with a customised control platform. The entire upgrade involved 1200 fan-coil units in the 10 storey building and is predicted to achieve energy savings of 75%.
Norland Managed Services, Cinque Energy Solutions and ebm-papst worked together on the project. The aims of the upgrade were to reduce the energy consumption of the HVAC equipment, reduce noise, reduce the need for maintenance and increase the controllability of the HVAC system.
The work involved the manufacture, supply and installation of new EC fan decks and controls. The 4-speed AC fan decks were replaced with EC units with 0 to 10 V control of speed.
There were two sizes of FCU, and one unit of each size was first installed to determine the difference in consumption compared to the old units.
The large AC unit drew 247 W compared with 49 W for the EC fan deck. The small AC fan deck drew 150 W compared with 54 W for the EC fan deck.
Following the trial, modifications were made that included increasing the number of fans in the large unit so that they could be run at a slower speed to reduce energy consumption and noise. Additional controls and monitoring enabled remote speed setting and feedback.