I have gone through two of these heaters. I use it at work every now and again under my desk to keep me warm in my office. The first heater the blades started warping from the heat and one blade fell off. I purchased another heater (thinking the first was a fluke) and the blades are warped again and I can't use it without it making an awful sound. It doesn't even work all of the time either because the blades get caught on the front grate from them being warped. Not a good product. I would never buy another one. It's just junk product.