17 October 2006

Use of CO2 in heat pump systems – practical experience with transcritical systems

The use of CO2 as refrigerant in heat
pump and refrigeration systems has
increased over the past few years
in Denmark, especially in the Danish
commercial refrigeration market
(e.g. in supermarkets). The Danish
environmental authorities have implemented
a plan for phasing out
HFC refrigerants, and the plan has
initiated a lot of activities within
the fi eld of alternative refrigerants.
An essential part of the work has focused
on the use of transcritical CO2
in heat pump systems.
This presentation concentrates on
four projects concerning the use of
CO2 as refrigerant in small, mediumsized
and large heat pump systems:
• CO2 used in domestic hot water
heat pumps
• CO2 used in heat pumps for commercial
• CO2 used in HVAC systems (air
conditioning and heat pump systems)
• CO2 used in large heat pump systems
for district heating.
It also presents project results obtained
through a combination of traditional
R&D projects and fi eld test
measurements. Finally, the discussion
considers the future of CO2in refrigeration
and heat pump systems