R22 systems use mineral oil. Operated at a higher pressure, R410A systems, on the other hand, require high-grade synthetic oils. As excess oil accumulates in pipelines and retains chlorine residues and humidity, this can lead to chemical reactions in synthetic oils, which will ultimately result in compressor damage due to insufficient lubrication. This is why, until now, pipelines also needed to be replaced to use R410A, a somewhat costly process. With Replace Technology Principle, Mitsubishi Electric now offers the possibility to continue to use existing pipeline networks.

Mitsubishi Electric has developed a special, synthetic refrigerant machine oil for split systems with pipelines up to 40 metres long, which, thanks to its properties, cannot form a chemical bond with any mineral oil residues. The patented HAB (hard alkyl benzene) oil fully maintains its viscosity even when mixed with mineral oil. There is no need to purge the pipes or undertake any other measures to clean the air conditioning system. The old air conditioning units are simply replaced with new M Series units.

Mitsubishi Electric has developed a new scroll compressor for larger air conditioning systems with pipeline lengths up to 120 metres, a type of system mostly used in commercial applications. The compressor's special coating makes it possible to re-use old R22 pipelines. Degradation may occur during a compressor process which uses high hot gas temperatures as a result of impurities due to mineral oil residues. The new compressor coating ensures there is less frictional heat. This prevents old mineral oil from decomposing and producing aggressive substances. All standard inverters, power inverters and Zubadan units are fitted with this new technology as standard.

VRF systems which feature many branches and a large number of connected indoor units may contain oil residues which are difficult to spot and eliminate. In its City Multi Series, Mitsubishi Electric therefore offers a model range with a guaranteed replace function which automatically purges pipeline networks . The R410A is conveyed through the system in a two-phase flow pattern during an automatically launched purging operation, which lasts a maximum of two hours. During the process, it picks up all mineral residues, which are then separated from the refrigerant by a flush filter in the outdoor unit. The pipe dimensions in the City Multi Series have also been matched to the standard pipe diameters used in R22 systems in the corresponding performance class.