Well, I can't really rate it on anything, because it didn't work. I kept it for two nights. I played around with it. I went through the trouble shooting guide. It simply did not work. It was supposed to give off a cool mist (which I thought would help counteract the effects of being stuck indoors in dry heat all day), but it did not do anything. Theoretically, you set it up, wet the wick, fill the reservoir with water, and it gives off a cool mist. I did everything according to the instructions. I double checked the wick to make sure it was wet and that it was sitting in the water. When I turned the unit on, a mist started to emit from it, but it immediately stopped. I took everything apart and started over. Same thing happened. So, today, I took it back to WalMart. The associate at the service desk told me that they had other units returned for the same reason. Maybe this was just a defective unit, but I did not feel like messing around with another one, so I returned it for a refund rather than exchanging it. If anyone else bought one of these, I hope they had better luck than I did.