"Oil fouling of heat transfer surfaces of air conditioning and refrigeration systems, will cause a loss of about 7% efficiency the first year, 5% the second year, and 2% per year the following years." (per 1998 ASHRAE Handbook, Refrigeration, Chap.2.9)

IceCOLD® technology is NOT chlorinated and it is NOT a "PROA" - it is two synthetic catalysts; one that causes removal of the oil fouling and another that causes the refrigerant to evaporate at a lower temperature. "PROAs" developed in 1986 have as active ingredients either chlorine or sulfur which damage seals and bearings, damaging the compressor (Oxychem letter). Many "efficiency improvement additives" are just lubricants, one notable brand is actually soap, not recommended by ASHRAE.