R407 inside unit on old R22 compressor ?

[stephengrenfell]

hello

I have an old Daikin 3 way multisplit with R22 at my house. There is only 1 (out of the possible 3) inside units connected and I want to add an extra unit. Can I add a newer inside unit that has been used with R407 ?.

Thanks

[Andy AC]

The electronics on the newer unit might not be compatible.

Andy

[stephengrenfell]

Electrics are ok - interface is a single wire to switch the outside unit on or off by a relay (240v=on 0V=off)

So there is no issue with the diffferent fluids then ?.

[cool_tech]

hello, you could flush out the coil, new copelands. most new compressors come out with poe oil and R22 will still run if there is a little bit of poe and mineral oil.
someone who knows a bit more will be spot on.

[icecube51]

if it is a new unit,never being used,and the system is on/off,then there is no problem and it will work just fine. just don't expect that the R407 unit have the same quality as the R22 unit. if it is a used one,R407C,clean fermly the inner tubing,because the POE (polyester ether) oil will damage the mineral oil based compressor.

good luck, Ice

[stephengrenfell]

The indoor unit is an Airwell that is sold for R22 and R497 use. The actual unit I plan to use has been previously used with R22 - but I plan to add two more units (so I 'll try to get these new).

Many thanks for the advice.

[nike123]

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[icecube51]

so the outdoor unit is a Daikin and now there is an Airwell indoor on. or you are going to hang an Airwell unit on a Daikin ??
a bit confusing no ?? i don't think you can mount an Airwell indoor on a Daikin outdoor unit,ore the electricals has being fermly changed and work like an on/of system. even do, good luck.
Ice