Blog post dated April 19, 2018.
This two door enclosure is almost two years old. I am pleased with practically all of the design decisions I made. The one error I made was in designing the filter assembly. It was not until my recent round of research that I learned the carbon filter should be changed often and easily accessible compartments are needed for both filters.
I did not know until recently that the HEPA filter I used was unacceptable. Not because it was not a good HEPA filter, but because I ripped it while trying to remove it from its case, where it should have remained. I know now that the filter must remain potted in its case to be effective.
One other change needed for the enclosure was insulation around the doors. I used rubber window seal for this.