When summer approaches, a window air conditioner can be your best friend, an easy and relatively inexpensive way to transform your room from a sauna into an oasis.While it may seem that window ACs have remained relatively unchanged, a few recent innovations help them cool rooms more efficiently. In this article Best Windows ACs for a: Small Room Midsized Room Large Room How CR Tests Window ACs U-shaped units from companies like Danby, Frigidaire, Midea, and Soleus allow you to raise and lower your window while the air conditioner is installed, taking advantage of a cool breeze or insulating your room from the heat and noise outside. Many of these models performed very well in our lab tests and can be found in this roundup of top-rated units. But note that U-shaped ACs can be tricky to install and simply don’t fit in some windows. More on Air Conditioners How to Properly Size a Window Air Conditioner Most and Least Reliable Room Air Conditioners Quietest Window Air Conditioners How to I...