R32 is premium gas for premium aircond(Daikin Urusara 7 series for example), so if you can afford one such aircond then go for it as it is more environment-friendly..When it comes to safety, should be almost the same with normal R410a

If usage more than 8 hours per day yes u can save with inverter unit, if less than that you can opt for normal aircond..The key in saving is the reasonable temperature setting and accurate BTU calculation matching your room needs..When it comes to maintenance, yes inverter aircond parts tend to be more expensive but when it comes to gas prices it should be the same as all newer aircond(inverter and non inverter included) unit is using R410a (well unless you were getting the more premium unit like Daikin Urusara series, which uses R32 gas)

This post has been edited by Devil7801: Sep 5 2017, 11:52 PM

5-6 hours for 27 degree u can use non inverter as the electricity saving is not that much(the main difference between inverter and non inverter is the compressor can slow down compared to non inverter which only has on and off)

For BTU calculation, there is so much to consider in BTU calculation..room length, width and height..Also need to consider window size, window position, room insulation,number of ppl in room, etc..However to make it simple, just download the Daikin Apps and key in your room spec under heatload calculator*..Once you get the BTU calculation you may purchase the aircond unit which match or exceed the BTU calculation..In general;
1hp aircond - 9000BTU
1.5hp - 12000BTU
2.0hp - 18000BTU

*Sidenote: For the heatload calculator, if your window is not facing sunrise, or if you always cover the window with curtain you can skip the info..just key in your room spec and number of ppl inside the room..
**Sidenote 2: I am not selling or promoting Daikin brand..I just use it as a reference and you may purchase any aircond brand that you like..

This post has been edited by Devil7801: Sep 7 2017, 02:03 AM