Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Too noisy to use; washable prefilter

It's nice that it's compact, but even the quietest setting is unbearably loud.The filter light is constantly coming on. I've replaced it with a different filter in the room, and there are other filters in the house; none need a prefilter fix as often as this one days.Taking off the cover, washing the filter (I've come to expect carbon prefilters, so a washable filter that stays in the machine seems strange), waiting for it to dry, putting it back together -- it's a pain when it indicates it wants it done every week or two. Especially when it's not even dirty.But the noise factor alone makes the thing useless. It's ridiculous. In a small room, that noise is the only thing that exists. It might possibly be a good filter, but if I can't even turn it on, it's a never-used, useless filter.