how to select the airconditioner for a room

You need to know the volume of air and how quick you want to cool it. Then you need to compensate for the room insulation, and adjust by the amount of air loss through cracks. Sunlight and outside air temperature needs to imputted.

Once you calculated BTU/Hr you can ignore the value and go to the store and buy the one that fits in your window.

Room Size.

Whether conditions- Hot/Humid ,cold

A good approximation that works for simple A/C applications : 800-1200 BTU/ft2.

For detailes see www.PDHonline.org appendex D rule of thumb

Rsidence 400-600 ft² floor area per ton of refregeration (12000 Btu/hr )

1 Room 400 ft² floor area per ton .

the capacity of airconditioner depends upon many factors: Starting from the ambient conditions (Temperature, humidity), number of people in the conditioned space, losses by means of leakage, etc. So, if you are in area where the ambient temperature is 30-35 deg C and the room walls are of masonary construction and the losses through the windows/glass etc are minimal. the cooling required in this case will be lesser as compared to where the ambient is around 45 deg C.

on thumb rule basis you may choose 200 sq ft area can be cooled by one ton ac in first case and 120 sq ft are by one ton in second case. (Approximately)

thank you

It reminds me of a building I once worked in. The building was purpose built to house a large computing centre and the support staff plus several administrative offices and a cafeteria. The computer areas were fully equipped with the appropriate air conditioning for the mainframes of the era including an uninteruptible power supply. The office space environmentals took into consideration the number of human bodies but they failed to take into consideration the fact that most of the people would have computer terminals which all generated significant amounts of heat. It was a really uncomfortable place to work until they upgraded the air conditioning. So take into consideration everything that might be generating heat like computers, laser printers, and high powered ham radio amplifiers.

If you go to Sears or there web-site, they should have generic tables on capacities vs. room size. Of course, as many people have indicated, there are many factors that can affect this. However, it should give you a good idea.

Good Morning,

The blaggers way will define the value easily,

Call your local A/C company get a detailed quotation, get a catologue for the kit selected hey presto you have your heat extraction value.

Good Luck and stay cool