Amazon.com: Hurricane Box Fan - 20 Inch, Classic Series, Floor Fan with 3 Energy Efficient Speed Settings, Compact Design, Lightweight - ETL Listed, White : Home & Kitchen
Home made box fan and CFM measurements - YouTube
BOX FAN - Industrial - Belt Drive - 36" - 1/2 Hp - 115V - 1 Phase 10,800 CFM - The VirTau Company
48 inch Schaefer Mobile Box Fan - 20,679 CFM, 1 HP and 115 Volt