本研究以一R22熱泵熱水器商品為雛型，進行商用二氧化碳熱泵熱水器的開發，藉由與挪威科學暨工業基金會(SINTEF)的國際合作，完成二氧化碳冷媒氣體冷卻器、鰭管式蒸發器與中間熱交換器的元件模擬設計，並經由組裝製作與環控實驗室的性能測試以及最佳化設計驗證測定，而完成商用型二氧化碳熱泵熱水器的開發。根據JRA4050測試標準的性能測定，所開發的二氧化碳熱泵熱水器在額定條件及冬天高溫加熱條件的加熱性能係數(heating-COP)分別達到3.26及2.55。

A heat pump water heater with carbon dioxide refrigerant has been developed based on the frame of a R-22 commercial water heater product. The tube-in-fin evaporator, tube-in-tube gascooler and internal heat exchanger have been redesigned with Hsim software from SINTEF. The assembling, optimizing tuning and performance measurement of this prototype also have been executed in a certificated laboratory in ITRI. According to JRA 4050 standard, the heating COP of this model under rated and summer testing conditions are 3.26 and 2.55 respectively.