How to Buy the Right-Size Air Conditioner

Size is an important consideration when buying an air conditioner. People believe that bigger is better, but that's not necessarily the case. Buy the right-size unit to properly and efficiently cool your room. Too large a unit wastes of energy, and too small a unit doesn't accomplish the task.

Difficulty:

Moderate

Instructions

1. Determine which room you are buying the air conditioner for. Before you can purchase the right-size air conditioner, figure out which room you're buying it for.

2. Know your room's square footage. Measure how large your room is. Guessing your room size once you're in the store can cost you in the long run. If you guess incorrectly, you may end up with too weak or too powerful a unit.

3. Refer to the rule-of-thumb formula. Here's a rule of thumb for calculating the size of your air conditioner.
   
   
   
   Room size: 100-250 square feet, Air conditioner size: 5000-6000 BTU
   
   Room size: 250-400 square feet, Air conditioner size: 6000-8500 BTU
   
   Room size: 400-550 square feet, Air conditioner size: 8000-11000 BTU
   
   Room size: 550-875 square feet, Air conditioner size: 11000-15000 BTU

4. Consider the room's characteristics. If you are buying an air conditioner for a room with high ceilings and lots of sun exposure, you then need a more powerful air conditioner than for a room with lower ceilings and no sun exposure. Buying the right size air conditioner is more than just the room square footage. Sunlight, airflow, number of people occupying the room and temperature preference all play a part.

Tips & Warnings

• The rule-of-thumb formula is just that--a rule of thumb. Other conditions determine the size and power of air conditioner you need. The rule of thumb is a nice place to start, but modify it to suit your needs.