Portable Air Conditioner Cooling Factors  View Models >>


Factors That Affect A Portable Air Conditioner's Cooling Power

Before buying a portable air conditioner (PAC), you should be aware of the factors that can limit the cooling power of your PAC.

1. Most obviously the larger the room the more cooling power is required. Here’s a chart that matches room size with the BTU required to effectively cool your room.

Area To Be Cooled (ft2)
Estimated Capacity (BTU/Hour)

It’s important to match your room size with the appropriate amount of BTU. A unit without enough BTU will run constantly and will never properly cool down your room. A unit with too many BTU will “short cycle” on and off again which is bad for the compressor. For rooms over 525 square feet, consider purchasing two PACs that when combined sufficiently meet the cooling needs of your room. Use the chart above to calculate the BTU needed for your specific room.

2. Rooms that are excessively warm or in direct sunlight will require a more powerful PAC. Traditionally, very sunny rooms require a 10% increase in BTU. Realistically, PACs are used to “spot cool” one room. PACs are not suited for multiple rooms or excessively hot environments. These types of rooms merely force the PAC unit to draw in more and more hot air, much more than these units can effectively vent. Think of it this way, a central ac unit would require several hours to cool down a room in excess of 90°F to a level that's comfortable for most people. While central ac is designed to be powerful enough to cool down several rooms, a PAC unit is designed for single room use. With this in mind, a PAC unit will not be able to cool down an extremely hot room immediately.

Speaking of hot environments, rooms like the kitchen require additional BTU. Typically a warm place like the kitchen requires an additional 4,000 BTU for your PAC to cool the room effectively.

3. The length of the exhaust hose that vents your PAC should never be overextended. Manufacturers have determined the correct hose length, and you should always refer to the owner’s manual for the correct length. Overextending the hose can limit the smooth and easy flow of hot air and backpressure will develop, decreasing the efficiency of your PAC. You should always place your exhaust hose as close as possible to the vent so that hot air can be quickly and efficiently vented out of your room. Also, make sure the exhaust hose does not have any bends or kinks as this may obstruct the flow of air being exhausted.

4. Something that often goes overlooked is the number of people occupying the room. Beyond two people, it is recommended that for each additional person that regularly occupies the room, 600 BTU be added to your PAC.