At this time, portable room air conditioners are ENERGY STAR certified products. The Department of Energy has released federal standards to to regulate the energy consumption of portable air conditioners. ENERGY STAR will determine whether to add portable air conditioners to the program once a federal standard is set.
Portable air conditioners are small movable units often used to supplement a room's existing cooling. They are used in some cases as a short-term solution for cooling and dehumidifying during the summer months. However, they only cool a room overall if their exhaust is connected to a duct to the outside of the room - otherwise they are just cooling one spot by heating the rest of the room. Due to their limitations, portable air conditioners should not be viewed as interchangeable with room air conditioners that are placed in your window or through-the-wall.