Mafron R-407C

Mafron R-407C is a zeotropic HFC blend of R-32 (23%), R-125 (25%), and R-134a (52%), engineered to match R-22 operating pressures closely — making it the established retrofit path for existing R-22 air conditioning and refrigeration equipment where full replacement isn't economical. Zero ODP, non-flammable, ASHRAE Class A1.

The engineering caveat that separates a professional supplier from a cylinder shop: R-407C is a zeotropic blend with real temperature glide (~5 K). It must be charged as liquid, fractionates on leakage (top-up practice matters), and requires a POE oil changeout when retrofitting from mineral-oil R-22 systems. Every Mafron R-407C quotation from Refrigeration Controls comes with retrofit guidance and matched POE oils from our range.

Also asked for as: R407C gas, HFC-407C, R-407 gas, and "R-22 replacement gas" — the last of which is the phrase that brings most buyers here. It is also occasionally confused with R-407A and R-407F, which are different blends for different duties; if a drawing names one of those, send it to us before ordering.

Where it is used: retrofitted R-22 ducted, packaged and split air conditioning; air- and water-cooled chillers; cold rooms and medium-temperature refrigeration; and new equipment built for R-407C in the years between the R-22 phase-out and the R-410A/R-32 generation.

Three rules that decide whether a retrofit succeeds. Charge liquid, always — charging vapour from a zeotropic blend changes the composition of what enters the system and of what stays in the cylinder. Do not top up after a significant leak — the blend fractionates, so recover, evacuate and recharge to weight. And change the oil: an R-22 machine running mineral oil needs a POE changeout (typically three flushes to get residual mineral oil below the threshold), plus a fresh filter drier. Expansion valves usually need re-adjusting, and sometimes a different orifice.

Order Mafron R-407C when an R-22 plant is being converted rather than replaced, when a leaking R-407C system needs a full recharge to weight, or when new-build equipment is specified for R-407C. Tell us the system charge weight and we will confirm cylinder availability and quote the matching POE oil and drier at the same time.