This article will answer these questions and also provide you with some general guidelines for choosing the most appropriate size of room air conditioner for your cooling needs.
The highest BTU air conditioner that you can find these days is a 34000 BTU unit. We’ve seen Carrier selling these for window use. These are giant units and able to cool 2000-2500 square feet. If you go with a unit this size, you will definitely need 230 Volt electrical outlet to support this much power.
The smallest room air conditioner (generally a window air conditioner) that we have seen is a 5000 BTU unit. While these are tempting to buy because they generally cost about a hundred bucks, it is important to keep in mind that they will cool only very tiny spaces.
As you can see from the table below, a unit of this size will only cool about 100-150 square feet. This might work for a small bedroom or office.
Below, we’ve provided a table of the square footage that can be cooled for the different levels of BTUs. Bear in mind, however, that if you are trying to cool a particularly hot spot in your home (i.e. the kitchen), you will probably want to purchase an air conditioner with a slightly higher BTU level than what is required based on the square footage.
Square feet/BTUs per hour:
100 up to 150 square feet = 5,000 BTUs
150 up to 250 square feet = 6,000 BTUs
250 up to 300 square feet = 7,000 BTUs
300 up to 350 square feet = 8,000 BTUs
350 up to 400 square feet = 9,000 BTUs
400 up to 450 square feet = 10,000 BTUs
450 up to 550 square feet =12,000 BTUs
550 up to 700 square feet = 14,000 BTUs
700 up to 1000 square feet = 18,000 BTUs
1000 up to 1200 square feet = 21,000 BTUs
1200 up to 1400 square feet = 23,000 BTUs
1400 up to 1500 square feet = 24,000 BTUs
1500 up to 2000 square feet = 30,000 BTUs
2000 up to 2500 square feet = 34,000 BTUs