I have a brand new 25lb tank of Freon refrigerant. $190 firm. Still has the seal on the nozzle. A No-Oil-Change R-22 AC Replacement Refrigerant Industries, commercial businesses, property owners, and others looking for an R-22 replacement to maintain their air conditioning (AC) systems can turn to Freon™ NU-22B™ refrigerant. Freon™ NU-22B™ is compatible with all standard oils, equipment components, and materials used in R-22 systems. It does not require a time-consuming oil change that some other replacement refrigerants require. Features and Benefits Freon™ NU-22B™ has an ASHRAE A1 classification and is non-ozone depleting and nonflammable. It is well-suited for AC applications because it closely mimics the operating characteristics of R-22 and works over the same operating pressures as R-22. While all mainstream R-22 replacements earn lower capacity ratings, systems that convert to Freon™ NU-22B™ see a minimal capacity loss of less than 10%.