Part 7/11:
Despite substantial advancements, the development of high-temperature heat pumps faces challenges. The efficiency of both Carmon and Heaton systems drops as the temperature requirements increase. For example, Heaton reports coefficients of performance (COP) dropping from 5.4 in lower temperature lifts to just 1.9 in higher lifts. Carmon aims for a COP between 3 to 7, which would be particularly impressive at elevated temperatures.