Analysis of Greenhouse Gas Emissions Reduction Potential with Alternative Refrigerants for the Retrofit of Heat Pumps with Hydrofluorocarbons

To overcome the challenges imposed as the energy demand worldwide progressively escalates, heat pump (HP) technology stands as a potential solution to provide heating and cooling in an efficient and sustainable manner. Although HPs usually benefit from a sustainable and clean operation, the occurrence of faults might lead to serious consequences from the functional and environmental perspectives. That occurs because the most prevalent fault in such systems is the refrigerant undercharge, which usually arises from a leakage in the circuit and, since most systems still employ hydrofluorocarbons (HFCs) as refrigerant, it consequently entails a massive emission of greenhouse gases (GHC) due to their high global warming potential (GWP). Moreover, a refrigerant undercharge might also affect the system’s capacity, performance, and power consumption. Thereby, the present work aims to analyse the reduction potential in the GHG emissions through the utilization of alternative refrigerants for the retrofit of systems previously equipped with HFCs. For this purpose, the operation of Air-Source HPs with different refrigerants will be carried out and the resulting direct and indirect GHG emissions will be considered. The first one concerns the emissions that result from a leakage in the system, and the second one concerns the emissions that result from an increase in the power consumption. Summarily, the refrigerant retrofit in already existing equipment might provide a reduction of up to 10% in the indirect GHG emissions as a result of a decrease in the system’s power consumption.