Can Several Spot Air Conditioners Cool an Area?

How Air Conditioners Work

• Understanding how air conditioners work may help you to use several smaller units to cool a large overall area. Air conditioners, whether central units or spot units, cycle on when the thermostat detects a certain temperature, then cycle back off when the air is cooled down to a certain temperature. Because warmer air is more humid than cold air, air conditioners remove the humidity from the air to make it more comfortable.

Sizing Air Conditioners

• Air conditioners need to be properly sized for an area to operate effectively. Before you install spot air conditioners, first figure out the cooling needs of the area. You can determine this yourself, or enlist the aid of a heating and cooling professional. Factors include the square footage, the ceiling height, the number of people normally inside the area, the heat inside the area from lights and appliances and whether the area is shaded.

Combining Spot Air Conditioners

• To use several air conditioners in one area, combine units whose combined cooling capacity, measured in British Thermal Units (BTUs), matches the area's cooling requirements. If the combined cooling capacity of all the units is too great, the air conditioners will cycle off too quickly, or short cycle. After they rapidly cool the area, the units will leave it feeling damp and uncomfortable because they cooled the air so fast they don't have time to remove the humidity. If you use units that, when combined, are still too small for the area, they will stay on longer, removing the humidity and making the room too dry, while failing to adequately cool it.

Additional Considerations

• Before combining several small air conditioners to cool down one big area, consider other methods that would better help one large unit cool down and dehumidify the area. For example, seal any leaks inside that area that are allowing cool air to escape to the outside and hot air to infiltrate. Also provide better insulation for the area's ceiling and walls. Efforts like this reduce the amount of cooling required.