I completely missed this: https://www.filterboxbuilder.com
A webapp to create custom plans for DIY air cleaners based on the size/# of the filters and size/#/placement of PC fans
Based on this from Naomi Wu: https://github.com/opennukit/Nukit-Open-Air-Purifier/ (ht @kirk https://social.coop/@kirk/112688432394676824)
