The system, which is being launched in the US this year, consists of condensing units that reside on top of freezer or refrigerated cabinets. Each unit is fitted with a variable-speed BLDC compressor that operates efficiently by adapting to load conditions.
CAREL’s controller supplies inverters and electronic expansion valves with continuous modulation for optimal management of the compressors. The heat of condensation is carried outside the store via a water loop that is cooled by an outdoor cooling device or chiller.
Among the environmental benefits of the HEOS Sistema:
- Energy savings of up to 25% compared with a similar solution fitted with on/off compressors.
- An 80% reduction in refrigerant charge and a 96% reduction in leaks compared with traditional compressor racks.
- Improved temperature control inside the refrigerated case as a result of modulating the operating speed (15-90 rps) of the BLDC compressors.
- The water loop can be integrated into the HVAC management system, allowing heat recovery and savings in heating and cooling modes.
At present, the HEOS operates with R410A. However, “we’re seeking a natural refrigerant solution,” said Alessandro Greggio, CAREL group head of marketing for retail refrigeration.
The industry is moving to natural refrigerants. So we will get to natural refrigerants for this.”
In Europe, where the HEOS system was introduced, the majority of installations are in medium-small supermarkets with about 40 cases, said Greggio. But the system can be applied to larger stores with 120 cabinets. Typically each cabinet uses one condensing unit but it “depends on the size of the cabinet,” he said.
In terms of initial cost “cost neutrality with a rack compressor system is possible,” said Greggio. Unlike a rack system, the HEOS system affords flexibility in the layout of cabinets, which can be easily moved or decommissioned.