A.c is that electronical machine which enables us to control the temperature of any particular room by just setting the temperature.But a while choosing an Air conditioner for your Home, office etc so you must have to be very concious.Basically there are 3 types of A.c1) Split A.c - it is very aesthetic & considered as good for home. It has two part. First part i.e condenser is mounted outside of home & second part is mounted inside room.It create very less noise that’s why it is considered a good choice for bedroom.2) window A.c - As the name suggest this a.c can be installed only in window frame. It consist of one unit in a combine form of compressor & blower within it.It create loud noise while running3) Portable A.c - This is very new in india. It is just like air cooler. This a.c can move from one room to another another instantly.But as portable A.c is very new in india, they are expensive and also no known brand product os available in india.Now there are some tips while choosing A.c1) A.c size and capacity - choosing a a.c of correct size is quite hatic task. As oversize a.c cools the room faster than usual, but it consume electricity in very high amount.So, choose the correct size a.c according to your room sizeSave the electricity2) when you went to buy A.c in a showroom make sure to check you a.c that you are intended to buy to ensure that there is no flaws in that machine before you receive it as your own.3) if you choose split a.c then you should have to keep less no of windows because too much air ventilation may disturb the cooling rate.4) & If you choose window A.c, then make sure that your room has window in which that a.c should be installed comforatbly.5) try do compare the prices of a.c in different brand & showroom may be somewhere you found more discount as compared to previous one.6) Always try to buy A.c of some good brands likeHitachi, bluestar, whirlpool, haier, Daikin, lg, carrier, voltas, samsung, godrej, Lloyd, onida, kenstar.7) Always check the EER( Energy Efficiency ratio) Label. Now a days BEE provides stars 1to 5 so always try to buy about 4 stars it consume less electricity.8) lastly , buying a A.c is not a diffcult task but maintance is very important always protect it from dust and excessive heat. & also it needs proper maintance.so be careful while buying.