I remember talking about cleaning out the dust build up around the win 10 install, I had done a pretty through cleaning earlier but noticed the start of another build up of dust during the install.  Not that long ago I replaced the air filter for the forced hot air heating system and began thinking of a filter for the computer.  Anyways I just bought a small  air filter cut it to size and put it in front of the air inlet for the cpu.  Did a little cleaning on the fan and the fins of the heat sink.  I've seen better material that could have been used, same thing heater air filters, but I picked up what was available at the time and it's done for now.
Carl2

I like your thinking Carl2, dust is a problem with these air cooled PC's.

Why not use something off the shelf if it will do the job, it's the sort of thing I would do. 

  Good advice, I just took a look at newegg and they do sell dust covers made for this, very reasonable price.  Well it's done for now I'll try to check it in about 6 months.
Carl2

  6 months, about time to look in the computer, I think the air filter is laying on the floor besides the computer.  I can blame that on the cat.
Carl2