It will work awesome in 240 SF room as well. In my condition my ac is installed in Ground Floor room with no direct sun light. I don't know about your room criteria!
Didn't get electric bill yet as i installed in the last month. I will get my bill in this month end.
There are number's of ac brands in the market but all of them are almost same but costly. I was also confuse at the time of buying whether i should go for reputed brand like gree, haier or any other brand ac but finally after lot of search i choose dawlance inspire plus inverter 30 1.5 ton ac. I don't have any problem yet, cooling is awesome and taking 6.3 amp at staring which is quite economical. You will get this ac around 56000/Rs.