Dear friends, Inverter ACs are available in India for last couple of years. All Japanese brands and few other brands launched Inverter ACs in India. Standard ACs use a thermostat to automatically switch on/off the compressor to maintain required temperature level. As per the theory, such periodical switch on/off of compressor consumes more power. Inverter AC never switch off the compressor, instead, it uses electronics to run the compressor at variable speed to maintain required temperature.
The AC compressor initially runs at high speed to reach required temperature, then slows down to maintain the temperature. Result is less noise and more consistent cooling. It has high EER, and probably saves 10%-15% energy compared to 5-Star ACs in case of continuous use for long time. Marketing departments make tall claims, like it runs at 50% power than a standard AC after 3 hours of operation, but standard ACs also automatically switch off itself.
Some 5-Star rated ACs have higher EER than Inverter ACs. Most of the Inverter ACs use R410A gas. Companies also claim that these ACs have longer life, but on what basis is not sure, after all Inverter AC compressor never stops, it run continuously unlike standard ACs! Overall, it is more expensive but advanced technology, and the USP is more consistent cooling and energy efficiency.