The first hydrocarbon-based refrigeration technology for supermarkets has been unveiled by Waitrose.
The firm has announced plans to fit-out all new stores and major refurbs beginning with Altrincham in October with a system based on R290 propane chillers and R1270 propene-based integrated cabinets.
Waitrose believes it will solve the dilemma of being relatively simple to install and handle, and will not require major training on the part of its contractors.
Feasibility director Steve Isaiah said: “We like to think of ourselves as a small shop and for that reason we wanted to avoid industrial techniques in replacing HFCs in new stores. We did some initial trials on methods of heat transfer and came up with this system that primarily uses water.”
The system uses rooftop Geoclima chillers from Klimatherm, using water as the condensing medium supplying Carter integrated cabinets. It makes use of split coils to keep the propene charge under 400 g, together with liquid pump amplification and floating head pressure and conventional free cooling below 18 deg C.
“In our climate that gives us a lot of free cooling,” said Mr Isaiah. The system sees 75 per cent of the heat recovered going to water, with the rest going to air.
But the system claims to offer its highest energy efficiencies by being integrated into the store heating and ventilation. By diverting the waste heat from the cabinets into the cold aisles, Waitrose avoids the need for separate heating, enabling the stores to claim 20 per cent lower electricity load across the rac and h&v spheres.
Mr Isaiah said: “Although there is a capital investment in the refrigeration equipment, when the h&v is taken into account, the overall system is cost neutral.”