Another heat wave is inevitable, and just the memories of the last one have you sweating. If you're fed up with oppressive heat and humidity that keeps you up at night or greets you after a long day, it may be time to equip your room with an air conditioner. A window AC is an inexpensive, energy-efficient, and discrete solution to provide relief when the temperature climbs. Here are a few questions to consider when selecting the best window air conditioner for your space. The cooling capacity of an air conditioner is measured in British Thermal Units. Generally speaking, it takes around 20 BTU to cool each square foot of space. That may change depending on how much direct sunlight or shade a room gets, or if there are more than two people occupying the space. It's also important to note that too much cooling power is not a good thing. AC units also remove moisture from the air, and if they don't have time to do so before the temperature cools, you may end up with a cold, damp room.

For a small room of around 150 - 300 sq. ft. a window air conditioner with between 5,000 and 7,000 BTU will be sufficient. For a room between 350 - 500 sq. ft., select a unit with 8,000 - 10,000 BTU. For large rooms over 500 sq. ft., you can find window ACs with 12,000 or even 14,000 BTU and above. Most window air conditioners are designed to be easily installed in single or double-hung windows. It's a simple DIY operation, and most units include accordion panels to ensure a secure fit. You should still measure the dimensions of your window to be certain it can accommodate the unit. Air conditioners should direct air toward the centre of the room, so if your window is located closer to a corner, make sure to select a unit that allows you to adjust the airflow in the appropriate direction. Choose a model that's ENERGY STAR qualified and with a high EER (Energy Efficiency Ratio) to ensure low environmental impact and enjoy long term savings on your energy bill. Look for a unit with intuitive and logical controls that are simple to understand and use, and a slide-out filter that's easy to clean regularly.