What are the top window AC units? , is the Frigidaire FRA086AT7, as of 2015. Reviewers there scored it very highly for efficiency, cooling power, ease of use and price. What makes used ac window units run hot? What are some tips for ac window unit repair? lists three air conditioners as top-rated window units, each for a different room size. The best for smaller rooms is the GE AEL06LS, which is Energy Star-rated and does an excellent job cooling. The best medium-sized air conditioner is the LG LW8012ER, praised for its dehumidifier and energy saver mode. Finally, the best air conditioner for larger rooms is the Sunpentown WA-1211S. state that it did an excellent job cutting through muggy, hot air. There are five types of compact air conditioner units: portable, window, through-the-wall, ductless mini-split and packaged terminal. The average cost of having a new air conditioner installed is around $5,000, according to HomeAdvisor, as of October 2015. The cost of having an old air co...