Conference Agenda

The phase-out of high-impact refrigerants drives the adoption of low-GWP alternatives, with zeotropic mixtures emerging as promising candidates. However, their adoption introduces new challenges in adapting existing heat pump systems to maintain performance. This study evaluates the thermal performance of near-azeotropic R410A, and low-GWP zeotropic blends R454C, and R455A in a 4-kW indoor heat pump unit using a validated finned-tube heat exchanger simulation for cooling and heating modes. The results show that R455A and R454C exhibit significantly lower HTCs compared to R410A—61.4% and 49.5% in cooling mode, and 84.6% and 64.2% in heating mode, respectively—due to thermophysical property differences, reduced mass flux, and large glide temperature differences (GTD), which cause a cross-parallel flow effect. To mitigate performance losses, circuitry optimization is highlighted as essential. This study emphasizes the need for careful system adaptation to ensure effective integration of low-GWP refrigerants in heat pump applications.

This paper shows the energy behavior of a chest-freezer of 7ft³ when is tested in different conditions of temperature and humidity which correspond of three geographical zones in Mexico: north, center and south. The refrigerant used is R516A which is evaluated like substitute of R134a which is the baseline refrigerant in the equipment. Results show an increase in the refrigerant mass of R516A respect to R134a in a 29.4%. Taking account of use of R516A, an increase in both COP as cooling capacity was found for climate conditions of center zone in comparison with north and south zones of 25.86% and 31.59% for the first parameter and 12.6% and 3.8% for the second. Finally, a reduction in specific compression work was got in the climate conditions of center zone being this of 15.3% and 29% respect to north and south zones.

Increasing temperatures lead to human mortality directly, by means of physiological response to extreme heat but also indirectly due to drought, flooding, famine, disease, wildfires, infrastructure disruption, conflict, etc. Numerous studies have attempted to quantify the mortality risk of the various individual consequences of climate change as well as the overall impact. Emissions of fluorinated refrigerants, as used in refrigeration, air conditioning and heat pump systems make a notable contribution to current and future warming and therefore some proportion of the overall mortality can be attributed to those refrigerants. Alternatives include hydrocarbons, which have negligible global warming potentials and provided they are correctly selected, can provide lower energy consumption. However, their higher flammability introduces an additional hazard which can also lead to fatalities. This study compares the climate-related mortality risk of HFCs with the flammability fatality risk of hydrocarbons in order to determine whether their adoption is can benefit society.