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Window Air Conditioner Buying Guide

How to Choose the Right Unit

Sunny Rooms

If your room is very sunny, add 10% more BTU

People and Pets

For more than 2 people or 2 large pets in the room, add 600 BTU for each additional person or large pet

Rooms with Appliances

For the kitchen or a room with several appliances, add 2,000 BTU

High Ceilings

For vaulted ceilings or ceilings over 8 feet, add 20% more BTU

How to Calculate the Correct BTU

How to Calculate the Correct BTU

EXAMPLE: Window AC in a Bedroom
You have a 10' by 20' bedroom with 4 large windows that face the sun in the morning and the evening. Your ceiling is vaulted and the room usually has 2 people and a large dog in it.

To estimate the BTU required to cool the space, the math would break down like this:

  • Baseline square foot coverage:
    10 x 20 = 200 sq. ft. = 6,000 BTU

  • For rooms with a lot of windows, increase BTU by 10%:
    6,000 BTU x .10 = 600 BTU + 6,000 BTU = 6,600 BTU

  • For ceilings higher than the standard 8 ft. height, increase BTU by 20%:
    6,600 BTU x .20 = 1,320 BTU + 6,600 BTU = 7,920 BTU

  • For ceilings higher than the standard 8 ft. height, increase BTU by 20%:
    12,100 BTU x .20 = 2,420 BTU + 12,100 BTU = 14,520 BTU

  • Add in 1,800 BTU to account for both room occupants and the large dog:
    7,920 BTU + 1,800 BTU = 9,720 BTU

    With all factors accounted for, to effectively cool your bedroom, you would need a: 10,000 BTU window air conditioner

Features to Look For


Allows you to set specific time frames for your air conditioner to operate to match your lifestyle and your schedule.

Electronic vs. Mechanical Controls

Electronic controls allow for the ability to choose a more precise temperature setting, while mechanical controls are easy-to-use, but typically have non-precise temperature settings.

Sleep Modes

Designed to adjust temperatures and fan speeds for a more comfortable sleep environment.

Auto Modes

Pick the perfect fan and temperature settings based on your space’s current temperature.

Auto Restart Functions

This function will automatically restart the unit at previous settings in case of power outages.

Humidity Control

Window air conditioners naturally remove humidity while in operation. If you live in an area with high humidity, look for a unit that will efficiently cool and dehumidify — like Denali Aire air conditioners.

Remote Controls

Full-function remote controls allow for the ability to control all the unit’s features, from anywhere in the room.

Air Filters

Like all air conditioning systems, air filters are necessary on window air conditioners. To make your life easier, look for window air conditioners that use washable, reusable filters. These will not only save you money but are also eco-friendly.