How to Safely Handle R407A Refrigerant for Home AC Repair R407A is a zeotropic HFC refrigerant blend used primarily in low- and medium-temperature refrigeration. That first sentence matters because a homeowner who sees “R407A” online may assume it is simply another refrigerant that can be added to a central air...

Azeotropic vs. Zeotropic Refrigerants The difference between an azeotropic vs zeotropic refrigerant is mainly about what happens to a refrigerant blend as it changes phase. ASHRAE defines an azeotropic refrigerant as a blend whose equilibrium vapor and liquid compositions are the same at a given pressure, while a zeotropic refrigerant...

12 Refrigerant Charging Mistakes That Cause Problems Many refrigerant charging mistakes happen because a technician treats refrigerant charge as a pressure-only adjustment. A system can show unusual suction or head pressure because of airflow, outdoor temperature, indoor load, metering-device behavior, a dirty coil, a leak, or a sensor problem. Adding...