Why the Air Conditioner Is Blowing Cold Air But the Room Isn't Cooling Down

Improper Size

• Even if an air conditioner is working properly, if it is too small or too large for the space that it is meant to cool, it will be ineffective. If the air conditioner is too small for a large room, obtain and install a larger unit. What is often less known is that a unit can be too large for a room, and instead of being more effective, will simply turn into an energy waster by quickly cooling the room, then cycling off before it has time to properly remove the moisture or humidity from the room's air.

Choosing the Right Size

• The key to correctly picking an air conditioner for a particular room is to first figure out the room's square footage, then choose a unit with the cooling capacity matching the room's size. Each unit's particular cooling capacity is measured and expressed in British Thermal Units (BTUs) per hour. For square and rectangular rooms, determine the square footage by multiplying the room's length by its width. For triangular rooms, multiply the length by the width, and divide that total by 2. Although you should consult a professional to be sure, you can estimate that you need between roughly 10,000 to 12,000 BTUs per hour for every 400 square feet of room space. You need more BTUs if the room is extremely sunny or for a kitchen area.

Air Leaks

• The reason an air conditioner could constantly blow out cold air without the room ever getting any cooler could be simple. You may unknowingly have air leaks around the air conditioner between the unit and the window, allowing the cold air to escape to the outside. Check around the unit, and seal all open spots that you find.

High Indoor Temperature

• If the room or area itself that the air conditioner is meant to cool is excessively hot, the unit will not cool the air properly even when it is blowing out cold air. Take measures to prevent this on particularly hot days by installing shades on the room windows to prevent direct sunlight from shining in. Also ensure that the ceilings, walls and floors of your house are kept well insulated.