K. VISSER - KAV Consulting Pty Ltd

HFC refrigerants offer a solution to the Ozone Depletion Problems (ODP) associated with CFCs and HCFCs, but have done little about the Global WarmingPotential (GWP) associated with the use of CFC and HCFC chemical refrigerants, which is becoming an increasing concern. The other major issue is the highenergy consumption for both heating and cooling in buildings.A solution to both these problems is possible by using the natural refrigerants Ammonia (NH3) and Carbon Dioxide (CO2). NH3 has already made a noteworthy return in the cooling of buildings because of its thermodynamic efficiency and because its GWP = 0.The potentially high energy efficiency when retrofitting two stage NH3 and transcritical CO2 systems for the cooling and heating of buildings will reduce the primary energy consumption in buildings and the attendant Global Warming Emissions (GWEs) by up to 40%. In new buildings such systems would reduce the primary energy consumption and attendant GWEs by more than 60%.The possibility of using NH3 and CO2 together in one cascade system for the heating and cooling of existing and new buildings is also explored and shown to have considerable merit in buildings where medium to high temperature heat radiators are installed.

Ammonia (NH3) heat pump, Carbon Dioxide (CO2),parasitic heat, parasitic energy, transcritical CO2compressor