The Shark NeverChange™ Air Purifier MAX is another air purifier in the shark line up.  I use it in my kitchen like others to help remove cooking odors.  My problem is my house has a fairly open floor plan so the filter is probably undersized for what I am expecting it to do.  Also the name of this filter is a little misleading because eventually you will have to change a filter.  Until then you have to keep cleaning the pre-filters so it's all a trade off.  In the machines defense I have a woodshop in the basement so I am expecting it to do probably more than it is able to do because of the dust.