Also thanks to government regulation, manufacturers are required to clearly display EER ratings on air conditioner units, making it easier to comparison shop. Air conditioning is half cooling, half moisture removal. A unit that's too small for your room will not cool enough, while one that's too large will not remove humidity effectively. See how easy it is to install . You'll probably need assistance in installing a heavier air conditioner, and even with a lighter one, an extra pair of hands is a good idea.
Many units also require special installation.
Check for special requirements . Some large units require a special 220-volt plug, and some have louvers that blow air more to one direction than the other, a fact worth considering depending on where you're planning to install the air conditioner. Look for convenience features . Know what level of noise you're willing to live with . You may be willing to save some money on a noisier unit if you're not cooling a bedroom, but if you're a light sleeper, check out the Amana Quiet Zone models.