This AC works great!  Our downstairs living area is open concept to our kitchen, maybe about 450 square feet and it actually cools down the space pretty well.  We initially bought it for our guest bedroom, but when no guests are staying it is perfect for our living room.  It is much quieter than our AC unit we have in our bedroom.  This AC is smaller, but packs a good punch!  I definitely recommend this AC to anyone with a room 500 square feet or smaller.