To find the right portable air conditioner size you'll need to know the approximate size of the area you want to cool. This will tell you about how much cooling capacity you'll need from a portable air conditioner.
If you have more than one area that needs to be cooled, consider whether one unit can be positioned to cool both areas, or if you'll need multiple units. One large unit can often be set up to cool several small areas at the same time.
BTUs (British Thermal Units) are a common way to measure the cooling capacity of air conditioners. It's often simpler to call it the "size" of the air conditioner, instead of "how many BTUs" or "how much cooling capacity".
Follow the chart here only to get a general estimate of the "size" portable air conditioner you'll need to cool a certain sized area.
Note that different manufacturers will have different charts with different recommendations of BTUs for different sized areas. This is because the best size for your area depends on a lot of different factors. Varying charts base their recommendations on different criteria. This emphasizes the fact that your cooling needs are fairly unique.
|AREA TO BE COOLED||CAPACITY NEEDED|
|Square Feet||Square Meters||BTUs per hour|
|100 to 150||9.3 to 14.0||5,000|
|150 to 250||14.0 to 23.3||6,000|
|250 to 300||23.3 to 27.9||7,000|
|300 to 350||27.9 to 32.5||8,000|
|350 to 400||32.5 to 37.2||9,000|
|400 to 450||37.2 to 41.8||10,000|
|450 to 550||41.8 to 51.1||12,000*|
|550 to 700||51.1 to 65.0||14,000|
|700 to 1,000||65.0 to 92.9||18,000|
|1,000 to 1,200||92.9 to 111.5||21,000|
|1,200 to 1,400||111.5 to 130.1||23,000|
|1,400 to 1,500||130.1 to 139.4||24,000*|
|1,500 to 2,000||139.4 to 185.8||30,000|
|2,000 to 2,500||185.8 to 232.3||34,000|
* In the world of air conditioning, multiples of 12,000 BTUs are commonly referred to as a "ton." This does not mean the air conditioner weighs 1 ton! A "1 ton" air conditioner may only weight 150 pounds / 68 kg.
A 12,000 BTU portable air conditioner is called a "1 ton air conditioner." A 24,000 BTU portable air conditioner is called a "2 ton" unit. A 36,000 BTU portable air conditioner is called a "3 ton" unit, etc. Sizes over 5 tons (60,000 BTU) are called "mobile" air conditioners.
If you're in doubt, when you purchase or rent a portable air conditioner, tell your sales or rental consultant the size of the area you'll be cooling, a description of the area (shed, tent, trailer, etc.), and how many people will be using it. This will help them advise you on the best sized unit for your needs.