To comply with corporate sustainability initiatives, Whole Foods Market was searching for a natural refrigeration solution that would use propane as a viable primary refrigerant in their centralized supermarket rack system.
To meet the challenge, M&M Carnot designed and installed a propane/CO2 cascade refrigeration system containing 265 lbs. of propane spread across seven rooftop chiller units, including three for low-temperature and four for medium-temperature applications. The system’s propane never leaves the roof and is used to condense its refrigeration partner, CO2. The CO2 is piped up from a rack inside the building, directly below. Liquid CO2 is then piped down to DX evaporators in low-temperature cases and pumped to liquid-overfeed coils in medium-temperature cases.