HCFC 22 is a controlled substance under the Montreal Protocol and European Regulation and will be phased out on a global basis with all other HCFCs. HCFC 22 is already banned in Europe in most new equipment and is subject to a rapidly tightening cutback schedule. It is, therefore, now time to consider the options for replacing HCFC 22 which will become restricted in availability as these cutbacks come into effect.
RS-44 provides a low cost and easy solution to replacing HCFC 22 by avoiding a costly and technically unsatisfactory retrofit situation. By definition, any replacement for HCFC 22 must have no ozone depleting ability so that, in contrast to replacing CFCs (e.g. R12, R502) where there were 'interim' blends available (largely containing HCFC 22) enabling the existing lubricant in the system to be used, this is not an option when seeking to replace HCFC 22. R424A has a zero Ozone Depletion Potential, a similar performance to HCFC 22 and can be used with all types of lubricants.
The lower head pressure obtained when using R424A provides significant operational benefits, while the higher Coefficient of Performance reduces energy costs and has a beneficial effect on the Total Equivalent Warming Impact (TEWI) of the whole system. The significantly lower discharge temperatures and pressures of R424A improve the reliability and extend the life of the compressor, and reduce the problem of oil decomposition.
RS-44 has been designated an Ashrae number of R424A with a classification of A1, which is low toxicity and non flammable.