You can pay for a quieter unit, but this 8,000-BTU air conditioner is the best in its class. Efficient and "quietish," it emits a pleasant low hum, directs air well, and cools up to 340 square feet.

While shopping for your ductless air conditioner, you may see “SEER” with a number next to it. SEER stands for seasonal energy efficient ratio, which measures how much energy your air conditioner uses ...