CO2 applications: First hospital catering facility refrigeration system to run with CO2 in the UK

A CO2 unit supplied by Green & Cool has been installed and commissioned by CCS Refrigeration, through Aggora on behalf of Medirest to provide for the on-site catering requirements of patients, restaurant and hospital staff at the Homerton University Hospital in London, UK. The water supply for the large CO2 chiller cold room is run from the existing ammonia chillers supplied by J & E Hall and installed some 75 m away. Thus, the complete system runs on natural refrigerants, with the ammonia system chilling water and CO2 cooling the evaporators. Due to the relatively high condensing temperature, CCS Refrigeration required transcritical compressors even though the system will run sub-critically year round. The energy savings compared with a conventional system have been calculated to be 16.7% over the course of 1 year, excluding the savings from the installed LED lighting and fitted e-cubes which generate further 15% energy savings compared with conventional probes reading air temperature. Over a 10-year lifespan, 628 000 kg of CO2 emissions will be saved thanks to the use of a CO2 system instead of a standard HFC system.