Buy RS-52 Refrigerant | R502 Replacement | Commercial Refrigeration | 24 lb — Refrigerant Inc

RS-52 Refrigerant — R502 Replacement for Commercial Low-Temperature Refrigeration

RS-52 is a refrigerant blend developed by Comstar International as a replacement for R502 in older commercial low-temperature refrigeration systems. R502 was phased out under the Montreal Protocol due to its ozone depletion potential — but millions of commercial refrigeration systems were built around it, and many remain in service today. RS-52 gives commercial refrigeration contractors a practical, available option for servicing that equipment. Refrigerant Inc stocks genuine RS-52 in 24 lb cylinders with free shipping to all 48 continental states.

What Is R502 and What Systems Used It?

R502 was a widely used commercial refrigerant from the 1960s through the early 1990s, predominantly in low-temperature supermarket and food service refrigeration. It was an azeotropic blend of R22 and R115. R502 was phased out under the Montreal Protocol in the U.S. beginning in 1996 due to its high ozone depletion potential. Systems that used R502 include:

• Older supermarket low-temperature cases and rack systems
• Commercial walk-in freezers installed before the mid-1990s
• Low-temperature reach-in freezer cases in food service
• Cold storage equipment from the 1970s–1990s
• Some older transport refrigeration units

While R502 systems are aging, a meaningful number remain in service — particularly in older facilities where the cost of full system replacement has been deferred.

RS-52 Retrofit Procedure

• Recover existing refrigerant first — Recover all remaining R502 (or interim replacement refrigerant) before introducing RS-52.
• Oil change required — R502 systems typically run on mineral oil, which is not compatible with RS-52. A POE oil change is required before retrofitting.
• Check system components — Given the age of most R502 systems, inspect seals, gaskets, and expansion devices for wear before retrofitting. Older elastomers may require attention.
• Charge by weight — Refer to Comstar's RS-52 charge weight guidelines. Charge weight will differ from the original R502 specification.
• Verify operating pressures — Use RS-52 PT charts to confirm suction and discharge pressures after charging.
• Label the system — Update the equipment label with new refrigerant type, charge weight, oil type, and conversion date.

Why Buy RS-52 From Refrigerant Inc

• Genuine Comstar Product — Factory-sealed RS-52 by Comstar International.
• Free Shipping to All 48 States — No freight fees added at checkout.
• Same or Next-Day Processing — Orders placed before 2PM EST ship the same day.
• Contractor & Wholesale Pricing — Volume accounts available. Call 888-593-7366.

Shipping Information

RS-52 ships via ground freight to all 48 continental states. Alaska and Hawaii excluded. Most orders ship within 1 business day. Transit time is typically 2–5 business days depending on location.

Frequently Asked Questions

Can you still buy R502?
No. R502 production and import were banned in the U.S. under the Montreal Protocol phaseout. Reclaimed R502 technically exists but is extremely scarce and expensive. RS-52 is the practical replacement for servicing existing R502 equipment.

Does RS-52 require an oil change?
Yes. R502 systems typically use mineral oil, which is not compatible with RS-52. A POE oil change is required before retrofitting with RS-52 — this is more involved than some other retrofits and should be factored into the service estimate.

Are R502 systems worth retrofitting or should they be replaced?
That depends on the condition of the equipment and the customer's budget. Given that R502 systems are typically 30+ years old, full system replacement is often the better long-term investment. However, RS-52 is a practical option for extending the life of equipment that is otherwise in good mechanical condition.