mitsubishi replacement technology ?

[CONROD]

What is this all about?/How does it work? Apparently you can use existing pipework and just tag on a new condensing unit and evapoator?

[Brian_UK]

The new R410a units, inverters only I think, can use the old R22 pipework, if suitable.

The unit contains an extra filter and when first turned on will perform a clean cycle using that filter.

At the end of the cycle the filter is bypassed and not used again.

Info is available on Mitsi websites I think.

[Thermatech]

Replace technology is standard feature on the Mr Slim Power Inverter range.
The small units use a special oil & the larger units have special filter which is only used once on first start up for 2 hours. This flushes the old pipework with the new 410a refrigerant & any old mineral oil & contamination is collected in the filter. At the end of the 2 hours a solenoid valve shuts & the contaminants in the filter are permanantly removed from the system.

But there are limits on the length of old pipe you can use because R22 systems used larger pipe size than the new R410a units. So you need to check this out with Mitsubishi to ensure your application is within limits otherwise you could have compresssor failure & no warrantee.

From an engineers point of view,,,,,,,,is it a good idea to use copper tube which has been subject to hot gas / cold gas , expansion contraction for 10 years or more & then you are going to use this tired old tube for R410a with much higher pressure ?

The replace technology seems a good way to clean up any contamination in the old pipework but the actual condition & suitabilty of the old tube is another issue.
Most copper tube up to 3/4 inch has wall thickness which will allow for the higher pressure of R410a so that should not be a problem for any old R22 system which used interconnecting tube up to 3/4 inch.

I would suspect that this option has been made standard to make it easier & cheeper for endusers to convert to the high effeciency R410a inverter systems.
The latest inverter systems will use a lot less kw than old fixed speed R22 units so the end user will get a payback for the upgrade.

But at the end of the day it will be the A/C contractor who will be responsible for the suitable condition of the copper tube.