HVAC refrigerants, phaseouts, and replacing AC and heat pumps

R-22/Freon has been phased out (Jan 2020).  R-410A/Puron is also on the way out, with other refrigerants coming to the market in 2023 (R-454b in Jan 2023?) Questions: 1.     If R-454b is slightly flammable,… R-22/Freon has been phased out (Jan 2020).  R-410A/Puron is also on the way out, with other refrigerants coming to the market in 2023 (R-454b in Jan 2023?) Questions: 1.     If R-454b is slightly flammable,…Read MoreGreenBuildingAdvisor