Split Flow Bento Box (Remix)

I exclusively print ‘low temperature’ filaments such as PLA+ and PETG, but I still wanted an enclosed printer to protect from drafts.Even with the low temperature filaments I wasn't able to go into my garage for several hours after a print without feeling unwell. So enter ThruTheFrame's excellent BentoBox. However, with my ‘vision’ enclosure I couldn't help notice I was still getting a lot of untreated hot air escaping from the gaps around the frame. And the low temperature filaments were suffering from heat creep. I wanted to exhaust some air from the chamber - drawing in cold air to fix the heat issues - but by using one of the BentoBox fans instead of a separate chamber fan, I can guarantee at least one pass through the HEPA filter and carbon. The other fan continues to recirculate and provide some of the benefit i.e multi pass filtering and chamber air recirculation. When an exhaust fan is running there is an ever so slight low pressure in the chamber which encourages fresh air int