Instruct: Classify an Amazon review into positive or negative sentiment.
Query: Not very effective

I have the penguin version, which I just received. I measured humidity using a hygrometer. At full power, after seven hours, the humidity increased a mere 10% (22 to 32 percent...still dry by many standards) in a small 10 x 10 room.I therefore cannot recommend this device...it is inefficient.At the highest output, which I used, it is very, very noisy (water bubbling). I simply do not understand the misguided positive remarks here.