What You Need To Know About Refrigerants R22, R410a, R407c, NU22 Quantum Air Conditioning What is refrigerant? According to Wikipedia, a refrigerant is a substance or mixture; usually, a fluid, used in a heat pump (air conditioner) and refrigeration cycle. In most cases, undergoes phase transitions from liquid to a gas and back again. What are … More Ac Repair & Refrigerant Recharge