[Xringer]

Originally Posted by AC_Hacker

You'll need to make some kind of modification to the metering device, and also change out the compressor lubricant.

-AC_Hacker

The 'study' implied that R290 could be a 'Drop-In' replacement for R410a,
and that R290 would cool better and use less power..

It seemed like they didn't have to make any mods..
But, the last part does recommend a change be made to the capillary tube..
To avoid very high "evaporating temperature"..



"
For further discussion, even the optimum charge is
found from the experiments, the evaporating
temperature found to be very high 14.6C,

`For air conditioning application the temperature for
evaporation is 5C and condensing temperature is
45C.

`For the result above and requirement stated show that
there is an accurate result due to system setup.

`Even the manufacturer claim that R290 is suitable as
direct replacement for R22 andR410A (in the case of
this experiment), we found that minor modification
need to be done on the system.

`Suitable capillary tube should be change and follow
with further investigation.
"