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HVAC School - For Techs, By Techs

Oct 13, 2022

Trevor Matthews, the founder of Refrigeration Mentor, returns to the podcast to talk about why CO2 matters in commercial refrigeration and even HVAC applications.

CO2 (R-744) has entered the residential HVAC sphere in some places around the world, though it hasn’t come to the North American markets yet. CO2 is one of the most eco-friendly refrigerants on the market, with a GWP of 1, and it’s very good at moving heat. However, CO2 has some challenges, including its low critical point and higher pressures.  

CO2 comes with some safety concerns, and its systems have a complicated infrastructure. Since CO2 can exist as a liquid, vapor, or solid under operating conditions, you could end up with dry ice in the system. These issues require skilled, attentive technicians.

As the industry moves to natural refrigerants like CO2 and hydrocarbons, we need to stop the race to the bottom. Technicians need to learn how to take their time and do the job right when they work on CO2 equipment so that they can be safe and save energy. 

The future of troubleshooting will eventually lie in electronic controls that take measurements constantly. Technicians won’t lose their necessity with these changes, but it will be easier for them to respond to those measurements directly without connecting gauges. Technicians will also be able to access performance logs, which can help diagnose long-term problems.

Trevor and Bryan also discuss:

  • Trevor’s history working with CO2
  • Refrigerant regulations
  • Transcritical CO2 and climate
  • The skills and proficiency of young technicians
  • Dry ice in CO2 systems
  • Pressure transducers and pressure release valves
  • Manufacturer support and quality control
  • Data logging and electronic controls in commercial refrigeration
  • Trevor’s recommended resources for CO2 education and training


Check out Trevor’s mentorship and training initiative at

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