A window air conditioner is a compact cooling unit designed to fit in a window frame. It works by drawing in warm air from the room, cooling it through a refrigerant system, and then blowing the cooled air back into the space. This type of air conditioner is popular for its ease of installation and affordability, making it a common choice for apartments and smaller homes. Most window air conditioners come with adjustable settings, allowing users to control the temperature and fan speed. They also often include a filter to help improve indoor air quality by trapping dust and allergens. Regular maintenance, such as cleaning the filter, is essential for optimal performance.