Expert paper: CO₂ as refrigerant in Cooling and Heating systems

The transition towards low GWP refrigerants represents a significant shift in the world of cooling and refrigeration systems. Historically, synthetic refrigerants have been widely used due to their non-flammable and non-toxic properties. However, the adverse environmental impacts of these synthetic substances, particularly their role in depleting the ozone layer (CFC and HCFC) and contributing to global warming, have led to a pressing need for more sustainable alternatives.

Natural refrigerants offer a promising solution to mitigate the environmental concerns associated with synthetic refrigerants. These substances occur naturally in the environment and have minimal impact on global warming. Examples of natural refrigerants include carbon dioxide (CO₂), hydrocarbons (such as propane and isobutane), and ammonia.

The usage of natural refrigerants has gained momentum in recent years, driven by increasing
awareness of climate change and the need for sustainable solutions. A majority of research
and development efforts are directed to identify and optimize the use of natural refrigerants in various applications.

The application of natural refrigerants represents a pivotal moment in the refrigeration
industry’s journey toward sustainability. With their lower environmental impact and improved energy efficiency, natural refrigerants offer a viable and eco-friendly alternative. As the world continues to prioritize environmental-friendly solutions, the adoption of natural refrigerants is set to reshape the cooling and refrigeration landscape, contributing to a greener and more sustainable future.

CO₂ as refrigerant

Carbon dioxide, CO₂, also known as R744, has been used as a refrigerant in vapor compression refrigeration cycles since the 1880s. However, it lost market share to synthetic refrigerants in the 1930s due to energy efficiency, complexity, and technological limitation. In the 1980s, CO₂ made a comeback as viable solution, thanks to improved system and component design as well as manufacturing processes.

About the author:

Mazyar Karampour, Sustainable Applications Expert

Mazyar Karampour is an expert in the refrigeration, heat pump, and air conditioning industry. He has been a technical leader and researcher in the field of sustainable cooling and heating system solutions for over a decade. In his role at Danfoss Climate Solutions, Mazyar is dedicated to advancing the widespread utilization of natural refrigerants across residential, commercial, and industrial sectors. His support in the natural refrigerants matrix spans from product development at component and system levels, to technical advisory roles in formulating strategies for business growth. This incorporates close monitoring of market trends and environmental regulations. He is a member of both Industrial-Public Affairs and Applications-Systems-Technology Danfoss teams, underlining his commitment to driving progress and innovation toward a climate-friendly industry.

Mazyar holds an M.Sc. in Sustainable Energy Engineering and a Ph.D. in Energy Technology from the Royal Institute of Technology Sweden (KTH).  He has authored several publications, including his thesis, on the application of CO₂ as a refrigerant in the food retail sector.

RETHINK Live - Update on the new F-GAS regulation

With a new F-GAS regulation coming into effect, it can be a challenge to have a full overview of how it is going to impact you and your business. At Danfoss, we’re committed to providing you with the best and latest information to empower you to make confident decisions about the refrigerants to use with our products and in HVACR applications.