“COVID Cubes” improve indoor air quality.
As a rule of thumb, the clean air delivery rate (CADR) of your HEPA portable air cleaner should be equal to at least 2/3 of the room’s area.
Check out this site for CADR and approved cleaners: https://www.ahamdir.com/room-air-cleaners/.
These filters are inexpensive and can work in a 800 square-foot room.