Transcritical CO2 refrigerating systems applied to the cooling and heating of buildings reduce energy and cooling water.

The Kigali Amendment to the Montreal Protocol to phase down HFC production and consumption by 85% by 2036 in the G20 countries opens the door to the accelerated revival of the Natural Refrigerants (NR) CO2, NH3 and HCs for the efficient cooling and heating of the built environment. Using reported Specific Energy Consumption (SEC) data in kWh/m2/annum for cooling and heating in the EU built environment, projections are made on how the SEC may be reduced by retrofitting CO2 refrigerating systems to provide cooling and heating on demand separately or simultaneously, including the production of Domestic Hot Water (DHW). It is also observed that CO2 systems are suitable for cooling and heating new buildings with chilled and hot water for efficient hydronic building cooling and heating systems. Hybrid Evaporative Condensers (HECs) are used to save water compared to conventional evaporative condensers and cooling towers. It is furthermore pointed out that Multi-Function Two Stage Transcritical CO2 Systems with Parallel Compression are ideally suited to perform many simultaneous heating and cooling functions in food processing plants.