R22 to R410a Change over can i do this so ?

[sicctt]

hi guys
i have been in the industry about 15 years now so i have some measure of experience but i am humble enough to ask questions if i dont know. The r410a systems has just begun to hit my country. and i have a client who wants to change out 24 5ton systems and put in r410a 5 ton systems. the piping run is about 50-60 ft on each unit it is hard drawn copper.

my question is can i just remove the evaporator and condenser unit and replace it with the new one using the existing piping. if so what effect will the mineral oil traces in the piping have on the system

your advice will be greatly appreciated

Thanks in advance

[install monkey]

you'll need to flush the pipework out,as mineral oil and synthetic will not mix

[mad fridgie]

Firstly as IM has suggested and second is the increased pressure of R410a, is you pipework rated for the higher pressure, and thirdly is the pipe sizing correct to ensure proper oil return (velocity).

[JoeAT50A]

Please put extra care to remove mineral oil from existing pipe. N2 flushing is better.
Check your pipe size and thickness to stand the high pressure.
R410A has 1.6 to 1.7 times higher pressure than R22. And pipe sizes are one size smaller than R22 in general with same capacity range.
You need to look into insulation condition as well. Most insulation (Armaflex or whatever FLEX) could able to last 7 to 8 years the most.
More than 10 years old existing pipings, risks are higher.
Some manufacturers like Mitsubishi Electric has claim "Cleaning Free, pipe reuse" for upto 4-5 tons A/C and so on.
But make sure to check with your local Agent to have better solution. Some manufacturers said NO for existing R22 pipings.

[Paul a/c]

Mitsubishi Has done a system now for a few years where you can use the old pipe work. It filters it all out as it runs, we fitted have fitted few with no problems so far I see daikin have start to do one as well.

[install monkey]

there are rules for replacement technology! daikin and mitsi do them,and mitsi have dipswitches for pipe size difference,usually r22 suction lines are bigger.
mitsi power inverter are 5/8 3/8 upto 12kw.

[Ash Khan]

I have recently replace the R22 Daikin with R410A Mitsubishi Electric, if your old R22 unit is running then you don’t have to flush even and if it is not running for long time then yes you have to flush the pipes, I have used the pro flush kit.
I will say on the save site even if the unit is running still flush the old pipes but remember as everyone said check the pipe sizes first.
Good Luck