Being a very populous country, India needs electric power in huge quantities even when its average domestic consumption is much lower than the developed nations. As per the 2012 data, the average domestic power consumption per year was about 750 units (KWh). This translates into about 3500-4000 units per family on the average per year or about 290-330 units per month per family. Since this is an average value, the higher income families must be consuming much higher as the a good percentage of lower income group families might be consuming zero to 30 units per month. It is also interesting to note the wide disparity of domestic electric power usage across the various regions and states of India.
Most people are not very clear about the working principle of a common air conditioner unit. Any one who is thinking of purchasing and installing an air conditioner for home or small office purpose should try to understand the essential principle of working of an air conditioner.
In places where humidity is low and water supply is not a big issue, the evaporation type coolers are much preferable both on account of initial and running costs. As the summer heat goes up with lowering of humidity in the air, these coolers give very comfortable cooling. However, they are not useful when humidity goes up during the onset of rains after summer. They are also not very effective in the coastal areas of India due to high humidity.
It is also not a very prudent decision to spent much money for fancy features of air conditioners. Of course, such fancy features are for those for whom money is not a big issue.
The best brands in air conditioners in India are Voltas, LG, Carrier Aircon, Samsung, etc. Voltas is totally an Indian brand and the current market leader.
Though I have advocated for window a/c of one or 0.75 TR, such machines are apparently in short supply as the traders normally do not seem to be keen in selling these for obvious reasons. So, if you are thinking of low tonnage AC, you have to be a little persuasive with the dealers.