Freon 404A is a zero ozone depletion blend of HFC refrigerants Freon 125, Freon143a, and Freon134a. It closely matches the properties of Freon 502, making it useful for a variety of medium- and lowtemperature refrigeration applications. Leading refrigeration compressor and system manufacturers have approved Freon 404A for use in new equipment, including food display and storage cases, cold storage rooms, ice machines, and industrial refrigeration. Freon 404A can also be used to retrofi t many existing Freon 502 systems. However, it is not intended as a direct “drop-in” service fl uid. Refrigerants used in the past were either single-component products or azeotropic blends that behaved as a single component. For the most part, having a small glide like Freon 404A will perform the same as an azeotrope like Freon 502. But keep in mind that: The temperature glide of Freon 404A is less than 1.5° F (less than 1°C). This glide is usually not noticeable for all applications compared to normal temperature changes due to pressure drops. Because of Freon 404A’s low glide characteristics it is often suitable for fl ooded evaporator technology. Freon 404A will not signifi cantly change in composition due to fractionation. However, there will be a slight diff erence in composition
in the vapor phase, which is in equilibrium with liquid, such as in a cylinder. Always charge Freon 404A as a liquid from the cylinder into equipment or systems. Using Freon 404A in New Equipment Performance — In new installations, sizing and selecting compressors and other system components for use with Freon 404A is the same as the process for Freon 502. Compressor capacity, line sizes, etc., will be chosen properly to fi t the needs of the job. Lubrication — Freon 404A requires a polyolester (POE) lubricant to ensure complete miscibility between oil and refrigerant. Miscibility is important for oil return to the compressor, especially in larger systems with long runs of piping. Manufacturers supply equipment with the proper lubricant already charged, or provide specifi c recommendations on the type of brand of lubricant to be installed in the fi eld. Material Compatibility — New compressors are constructed with materials that are compatible with Freon 404A. Follow the manufacturer’s recommendations regarding materials used in parts already installed in the fi eld.