The filter named corsi-rosenthal boxes or cube constructed from four MERV-13 filters, duct tape, a 20-inch box fan and a cardboard box. 

These are efficacious in removing chemicals from air such     PFAS( type of synthetic chemical found in cleaners, textile and wire insulation) and Phthalates(found in building materials and personal care products), it reduce the concentratin of former by 40 to 60 percent and later by 30 to 60 percent respectively.