View Full Version : R22 - 410a based air cond inverter (outdoor) for refrig system using 134a-404a gas

14-05-2012, 05:34 AM
Hi all
Has anyone tooled around with trying to run a R22-410a gas based inverter outdoor air cond unit using 134a or 404a gas in it ?

I'm wanting to understand if I can connect a basic medium temp force draft refrig evap to it and control the inverter with the main indoor PC board and sensor off the old air cond indoor coil ?

I know this sound like quite a silly thing to do but there is reason behind it...

Of coarse I'd have to size both coils pretty much spot on yes, but will it work mmm ???

Penny for your thoughts O wise men !!! :cool:

The Viking
14-05-2012, 07:31 PM
The inverter is normally not controlled by air temperatures alone, more likely by a logarithm taking in consideration many factors including air temps.

On the other hand Daikin makes interfaces to run their outdoor units with any indoor coil, this could for example be a cooling and or heating coil in an AHU.

As for the gas, that will probably be a bigger problem. Why not run your indoor coil on R410A? Just change the expansion device and make sure it will take the pressure.



15-05-2012, 09:17 AM
Hi Mr V
Whats your thoughts on just running the whole A/C system on 410a as is and playing with controller sensor resistor to achieve requirered temps ie; cycling between 1-4 deg C ?
At minus 6 deg C the difference between 410a & R22 is 23 psig, thats not a huge difference, I'm thinking this could work OK.
I've achieved success in running a Mitsubishi bulkhead system for the last 5 years in a wine room I engineered for a client, it runs great and achieves 15 deg C most of the year in Australia ( Melbourne ).
Mitsubishi said they wouldn't warrenty the equipment as it was in constant load situation same deal really for a wall split installed into a server room. Not sure about you but I've seen many splits installed into server rooms that constantly run - day/night/winter/summer in cooling mode !!!

I know theres a big evap temp difference but what is possible from 410a, if R22 can run medium temp then maybe 410a can as well yes ???

Any feedback would I would be very interested in to hear