Here is my opinion about the most marketed air cooler makers - Symphony
Well what special about with the model 22i is that it could easily fill the cool air in a 500sq ft. of a flat.
With a capacity of 22 litres and with automated remote control functions like swing, cool mode, fan speed, timer of 1hr 2hr and 4hr and the power of the system, it fits it all.
You better buy it from a trusty dealer who can provide you with servicing on proper time intervals.
The cost is just 8K and weight is about 8kgs. If you prefer much cooler air, then put some ice blocks in the chamber and let it do the rest of the work.