The scientists tested new refrigerants, R452B and R454B, as replacements for the commonly used R410A in heat pumps. They wanted to see how well these new refrigerants perform. By running experiments on a liquid-to-water heat pump, they found that the new refrigerants can work just as well or even better than R410A. The new ones have lower Global Warming Potential (GWP) values, meaning they are better for the environment. The new refrigerants showed higher temperatures when released, lower power usage during heating, and similar efficiency compared to R410A. The amount of refrigerant added to the system affected how well it performed, with an optimal amount found for each type of refrigerant.