This Old House made a great video on the subject of using box fans with filters: https://youtu.be/aw7fUMhNov8 https://youtu.be/aw7fUMhNov8 I've been using the

This Old House made a great video on the subject of using box fans with filters: https://youtu.be/aw7fUMhNov8 https://youtu.be/aw7fUMhNov8 I've been using the design they showed in the video, but I will definitely try this duct-fan method, saving electricity is always a bonus.