The installers of my Air Clean told me there is nothing I need to clean -- they will come twice a year to clean the filter. They didn't mention a pre-filter that I need to clean. But they know I am afraid of heights so maybe that is why they didn't mention it? I'm not in the HVAC field so I'm not sure what you mean by cells that they clean? Are they in the filter? Pre-filter? Sorry, I don't mean to sound dense! One of the employees told me I really should have the filter cleaned 4 x a year to get the best performance. I do want to keep it clean. When HVAC folks come out twice a year to do a "tune up," as you say, what exactly should they do? I can remember them coming out and basically just checking the freon and splashing some water on my compressor. They didn't even go up to the attic! I wonder if it would be possible for them to come out to do the complete tune-up twice a year and just come out to clean the filter the other 2 x?