Adam in Suzhou sent me a picture of a creative solution to a filter problem.
The fan he had at his house had an opening that was slightly larger than the HEPA. So Adam cut out a piece of cardboard to close up the edges. Great idea!
Adam says, “It’s already turned slightly gray after one night!
Thomas is an Associate Professor of Behavior Science at the University of Chicago Booth School of Business and the founder of, a social enterprise to help people in China breathe clean air without shelling out thousands of dollars for expensive purifiers.