retro fit r22 to r410a

[philjd26]

hi,would it be ok to use exsisting piework from r22 to r410a provided i flush pipework?

rgrds phil

[p_p]

Hi Phil

Are there some problems involved in replacing the pipework?
I have flushed lots of pipe in the past for various reasons and allways used endoflush, allthough not as good as the old R11.
It would be good practice to replace if possible.

Regards

PP

[wambat]

Hi Phil,
R-410A’s pressures are about 50% higher than R-22. That's why R-410A cannot be used as a retrofit fluid in R-22 equipment. This is also true for pressure gauges, recovery tanks, recycling units, disposable cylinders, etc. A better solution to retrofit for R-22 equipment, is you could use R-407C and 417A to retrofit of A/C units, while for refrigeration, R-404A and 507A are available

[BigJon3475]

As long as the existing pipework is the size that is required for the new system then you will be fine with a flush...make sure you blow the lines out very well with nitrogen. Also make sure you install filter dryer and your purge nitrogen during brazing. Then when done with brazing make sure you pull a vacuum of between 250-500 microns and that it holds that with the vacuum pump turned off and everything equalized you may want to keep it above 4000 microns for a good bit to make sure you do not freeze any moisture in the system from pulling a vacuum to quick. Come back after a week of running and change the filter dryer. This may seem excessive but better to do it once then have to do it twice.

[Pooh]

WHY???????

Ian

What is wrong with 407??

[BigJon3475]

Is it a retro fit or a complete change out of equipment?

[philjd26]

hi, just doing a swap on a little split system,...weighed in endoflush and weighed it back out and blew the be jesus out of the pipe work wit ofn and gave it a vac to0 400microns so i sure it will be good..

[Peter_1]

Mitsubishi has special AC with special build in filters to flush the excisting system.
http://www.mitsubishi-aircon.co.uk/d....asp?id=152713 in the middle of the page

[aldematt57]

If the lineset is of adequate size and is in good condition, an R-11 flush would be acceptable, IMO.
I witness many competitors here in the states that do not even use a flush kit and simply purge with nitrogen. Many do not nitrogen sweep while brazing either. Bad decisions.

[Peter_1]

Flush with R11?
We even can't buy this for many years in our country.
The ODP's of all the refrigerants are compared to R11 and you still flush with R11?

[BigJon3475]

Probably meant RX-11

http://ftp.nucalgon.com/ftp/prodlit/3-112.pdf