Thinking of air-conditioning your bedroom? or the living room? read through.
The market place is a maze of sleek buzzwords, which are meant to distinguish one’s offering from the other’s, and that is to it. The real deciding factors for buying an AC(or any other product for that matter) are completely different.
Requirements?
Before buying an AC, you need to identify your requirements in BTU/hr.
12000 BTU/hr equals 1 Ton of cooling power, so naturally, a 1.5T AC will have 18000 BTU/hr rating. Technically, 1 Tonnage of AC means having the cooling power of 907 Kg of ice melting in 24 hours. While the dealer will try to peddle the brand/model which gets him largest margins, only you can determine the cooling power you require.
Your tonnage requirementts depends on following:
Maximum temprature of the city you live in - The hotter the city, the higher the BTU requirements.
Carpet area of the room - The larger the room, the higher the BTU requirements.
Number of people occupynig the room - More people, more cooling required.
Number of heat sources in room(Heaters, bulbs, tubelights, TV, Frige, Cooking range etc) and their usage pattern - Remember, the AC has to counter the heat generated by your TV too.
Sunfacing? - A west facing room, which sees sun set gets more heat than an east facing room.
WIndow size - Big windows means more cooling requried, remember green house effect?
Top floor - The roof area adds to the sunfacing area in 5 above.
For most of India, where summer nights see tempratures upto 38 degrees celsius, start with 8000 BTU / 100 sqft as base figure. and add 5-10% allowance for each of 2 through 7. A top floor east facing bedroom of 110 sqft, for two people, plus two tubelights and a TV will never need more than 11000 BTU, unless it has victorian windows. You can work up your requirements aaccordingly.
*Brands brands everywhere, what a brand to choose!
*Forget about Blue-Fin / Gold Fin / Silver Nano/ Quadricool / Two moter / Durakool / blah blah. They are just marketing tools. I wonder how much value each of these add to the final product to command a premium!
Compressor is the heart of the cooling machine. These days, almost all compressors are rotary(costs less), and all are made in China(again, costs less). The relative differentiation is further reduced due to similar warranty terms(5 year) on most brands. Japanese names sell, is an axiom, however.
Cooling power!
The ACs cool the air by evaporating the refrigerant in the copper ducts, and transferring the heat outside. This means, the more the ducts, the better. Obviously, more copper means more costs. The myth of 2 fan motors does not contribute to cooling to the proportion of premium it attempts to command.
*Effecicncy
*To compare ACs of different brands, and differnt BTU ratings, just try to find its effeciency. Effeciency is output / input. Thus effeciency of a 14300 BTU(1.2Tr) unit rated as 1355W(input) power has effeciency of 10.55, while a 12000 BTU(1Tr) unit rated as 1300W(input) power has effeciency of 9.23. Clearly, the effecient machine is better. The effeciency is also quoted as EER or Energy Effeciency Rating on most brouchres. Effecient ACs may cost more, but bring a less inflated electricity bill.
Buzzzzzz
All ACs generate noise. A quite room is supposed to have 40dB of noise. Furthermore, a 3dB increase in noise means double noise, since dB scale is logarithmic. For a sound sleep, it is preferable to have noise level in early forties.
Helping hand
You need a remote to on/off the ac from bed, and if you don’t want to fumble with the remote in dark, it better be backlit. Another important things is after sales service, for which world of mouth is better than statistics. Look out for TollFree numbers of your favourate brand and talk to them.
In conclusion, you will be buying an AC to cool your room in summers. If the machine is able to perform this basic function, it qualifies to be called an AC. All else is frills. Window Vs Split is a matter of individual choice, though.