Air conditioners are meant to be installed with the room in mind, since its main function is to remove all moisture from that room. It is in fact by removing the moisture from the room that an Air Conditioner creates the cool atmosphere that we associate with it. The size of the machine matters since it determines exactly how long it will operate, and if it will work long enough to remove the moisture from the room. In case your AC is too big for the room you have put it in you should probably know that it is making your room less cool than what a smaller unit would. In case you want the other rooms to be cooled too get yourself a couple of smaller units and fix them in all your rooms.
Ratings for AC’s are given in terms of BTU’s (or British Thermal Units). BTU gauges what amount of heat is being taken from the room and being thrown out. Since heat is going from inside your room to outside it therefore the cooling coil indoors is cool and the one hanging outdoors is equally hot.
Most window AC’s do not have the sort of blower to cool a couple of interconnected rooms, so no matter how much you want it to do that, it won’t. In case you want the other rooms to be cooled too get yourself a couple of smaller units and fix them in all your rooms.
In case your AC is too big for the room you have put it in you should probably know that it is making your room less cool than what a smaller unit would. Because its run time is too short, which makes it incapable of removing the required amount of moisture from the room and making you feel comfy and cool.
That really depends on the size of the room you want to put it in. Suppose the area of your room is between 100-250 sq.ft in size, then you will do nicely with a 5000-6000 BTUAC. If the room is anywhere between 250 and 400 in size you can manage comfortably with a 6000 BTU to 8500 BTU machine.
Before deciding the size of your AC therefore you need to decide which room you will be putting it in. Most people think the Bedroom is the ideal place for an AC. Many even find the low humming sound of the AC a great comfort, almost a good replacement for a lullaby!
Of course there is no strict rule stating that you must place your AC in the bedroom. You might not like the cold atmosphere while going to bed and can therefore choose to put the machine in the living room instead, where the whole family can enjoy its benefits. If you have a large number of people sleeping in some master bedroom or a general room it would also make sense to put the AC there, else you might have to wake up with your dogs and kids who crawl into your bed just to be in the AC!