This unit is the most powerful on the market for its small size.It plugs straight into a normal 13amp socket. It produces 18000btu (5.2Kw) of cooling and heating yet uses less than 2Kw of electricity. We bought ours for use in a large office and it has proved very efficient. The best thing is you can speak on the phone whilst it is running because it is not as noisy as some less powerful units. We are now planning to get another for our server room. One of the useful design features is that it has an extra pump built in so that even if the room is really humid this unit will not produce water that ends up having to be emptied from a bucket. Under normal conditions the water will be ejected down the exhaust hose but if its really humid the extra pump kicks in and pumps the water away. Koolbreeze units are not the cheapest but they are reliable. I bought a smaller one back in 2007 which is still working. This new larger unit is really a breakthrough in the amount of cooling you can get from a small machine