It DOES ACTUALLY work pretty good. However the design is flawed. The air does NOT flow freely. It is SEALED by a rubber trim ring NOT ALLOWING the air to EXIT properly. I realise that's how it's made, but NOT allowing the air to exit the unit freely WILL AND DOES cause the built in fans to fail prematurely by putting a back pressure load on them, causing them overload. I modified it so the air DOES flow freely.