Wall-mounted air conditioners are compact cooling units installed directly on a wall. They are designed to cool individual rooms or small spaces, making them ideal for apartments or offices. These units typically consist of an indoor and outdoor component, connected by refrigerant lines. These air conditioners are energy-efficient and often come with features like programmable thermostats and remote controls. They can be easily installed and require minimal maintenance compared to central air systems. Popular brands include LG, Friedrich, and Mitsubishi, which offer various models to suit different cooling needs.