Use this with the windows open otherwise you end up with a humid and hot room. But when used like this, it cools you directly really well. It wont cool a room but should be used to blow cold air on you. Its not like aircon and wont replace it, but for what it is, this is great. The large tank means Im not always filling it up and, when you add small ice packs to the tank, like small Coleman Packs, it really helps the evaporative cooler. Its a good solution for specific purposes.