Why Use CO2 In A Heat Pump? | Clade Blog
This paper is intended to set out the technical basis for CO2 (R744) as the preferred working fluid for heat pumps. The vapour-compression cycle, as used in both heat pumps and refrigerators, has an intertwined history, with refrigeration being the dominant service provided to date. Therefore, the term “working fluid” and “refrigeration cycle” has become commonplace. In order that this paper reflects the changing market “working fluid” and “heat pump cycle” will be used.
Simple comparisons between CO2 and other working fluids such as HFCs can be misleading because its low critical temperature either requires differences in system design, such as the use of cascade systems, or to transcritical operation. As a result, like-for-like comparisons are not easy to make. This paper will attempt to set out the reasons why CO2 should be the working fluid of choice for heat pumps in many applications, giving comparisons where possible.