The old standard: R-22.

Acting in accordance with an international treaty called the Montreal Protocol, the U.S. Environmental Protection Agency (EPA) has mandated the phaseout of R-22 through the Clean Air Act. As of 2010, the manufacture of systems using R-22 refrigerant was prohibited, and by 2020 the production of R-22 itself must cease.

The main reason for this regulatory action is that R-22 is a hydrochlorofluorocarbon (HCFC) compound, which contains ozone-depleting chlorine.

The most common refrigerant available today: R-410A

Thermal Zone has transitioned to the manufacture of cooling systems that use the EPA-recognized chlorine-free R-410A refrigerant. Because R-410A contains no chlorine, it is considered ozone-friendly.

System matching – If you purchase an air conditioner that uses R-410A, your HVAC technician will need to inspect your indoor unit to see if it meets the performance requirements of the R-410A system. If the indoor unit is older, it will likely need replacing.

The most environmentally friendly refrigerant available today: R407C.

The most environmentally friendly air conditioning system in North America is the Thermal Zone model TZAB residential comfort cooling system with R407C refrigerant.
 

• R407C has ZERO Ozone Depletion Potential!
• R407C has lower Global Warming Potential than R22 (the standard refrigerant for the last 50 years).
• R407C has lower Global Warming Potential than R410A (the most common refrigerant used today).
• R407C is readily available at Refrigerant Supply House.
• R407C is priced competitively with other refrigerants.
• R407C operates at pressures similar to R22 (the most common refrigerant for the last 50 years), and much lower pressures than R410A.