ENERGY STAR room air conditioners with variable speed offer innovative features to help save you energy. In a standard AC, the compressor works either at maximum capacity or it turns off when your desired temperature is reached. It alternates between full on and off. Variable speed ACs vary the speed of the internal compressor to continuously control the temperature. As a result, they quietly regulate temperature and save significant energy. (Source: ENERGY STAR)

Getting the right sized room air conditioner is all about matching the room size to the AC. If you pick one too big it will be less effective and efficient because ACs remove heat and humidity from the air. A unit that’s too large will cool your room before removing humidity and will make it feel damp and clammy. So, it’s important to measure the square footage of your room that needs to be cooled and buy the right AC for it. ENERGY STAR offers tips for effectively measuring different shaped rooms. (Source: ENERGY STAR)

Aside from the size of the room you need to cool, when looking at ACs you should also consider the amount of sun or shade in the room that needs to be cooled, the number of people that regularly occupy the room, what type of room you’ll place the AC in, and where you will install the unit. ENERGY STAR has guidance on how these factors can impact the cooling capacity you’ll need. (Source: ENERGY STAR)