Genetron® 404a (R-404A)

honeywell Genetron® 404A (HFC-404a) is a non-ozone depleting compound designed to serve as a long-term alternative to Genetron® 502 (CFC-502) and Genetron® 22 (HCFC-22) in low- and medium-temperature commercial refrigeration applications. Applications where Genetron® 404A is a suitable retrofit refrigerant include supermarket freezer cases, reach-in coolers, display cases, transport refrigeration and ice machines.

Genetron® 404A has been designed as a substitute for Genetron® 502, but it is not a drop-in replacement. Mineral oils and alkylbenzene lubricants, which have been used traditionally with Genetron® 502, are immiscible with Genetron® 404A. Service technicians should consult the original equipment manufacturer for the recommended lubricants.

Genetron® 404A is a blend. For this reason it is essential that systems be charged only with liquid from the cylinder, not vapour. Vapour-charging Genetron® 404A may result in the wrong refrigerant composition and could damage the system.

A lubricant miscible with HFC refrigerants must be used with Genetron® 404A. Honeywell recommends using a lubricant such as polyol ester (POE) that has been approved by the compressor manufacturer. Differences among polyol ester-based lubricants make it difficult to assume that they are interchangeable. Check with the compressor manufacturer for the correct viscosity grade and brand for the compressor in the system being retrofitted.

Expansion device
Most Genetron® 502 systems with any common expansion device will operate satisfactorily with Genetron® 404A, however, it may be necessary to adjust the superheat. For Genetron® 502 equipped with a capillary tube, in most cases the unit can be operated satisfactorily with the original capillary tube by undercharging the unit (as long as ambient conditions are relatively constant).