very specific question. what's sure: R22 is beeing phased out because it harms the ozone layer. that for me is enough reason no to use ACs with R22 and i dont.

now to your question: R401A tends to be more energy efficient than R22. if i remember correctly by 10-15% but i really dont have the supporting figure at hand anymore. i looked into this around 4 years ago when i changed my ACs to 401A inverters. i found an interesting read on the issue here:

https://docs.google.com/viewer?a=v&q=cache:...zusFVDI_EZB-DUg

In some country, they stop using R22 for new equipment, but use difference direct replacement gas for same identical machine, even same copper. Think in global market there are few direct replaceable gas for R22 without modifying the HVAC.

My friend been bring some of difference direct replacement gas via Singapore for testing. All he can say, is hell hard to bring in gas to Malaysia, lots of restriction and special permit... you know what. The loosing end is the customer.

He tested some, and seem to have good feedback. But all he can do is just small quantity for testing.

R410A in technical analysis is not very efficient at higher temperature.

Daikin, 1 hp inverter, the one that uses the regular gas. It's the DVM series, which had something like that EcoNavi feature. The new GVM series does without EcoNavi, and is more expensive... seems like about RM 50 more. Paid RM 1150 for the Daikin, plus installation.

Panasonic got this function too, even on non inverter.
But I found it bad when sleeping,  when I switch this function on, it raised the temperature and feel stuffy. My sleeping temperature usually 23 to 24.  If it raised another 2c feel stuffy. I switch this function off.

Maybe daikin can sense sleeping and still remain the original temperature.