91.21—Ventilation.
Each underdeck compartment on which animals are being transported aboard an ocean vessel shall be equipped with a system of mechanical ventilation that will furnish a complete change of air in each compartment every 2 minutes when deck height 8 is less than 8 feet and every 2 1/2 minutes when the deck height 8 exceeds 8 feet. Spare motors and fans shall be available on board, for replacement or repair of the ventilation system during the voyage. A spare motor and fan of an approved type in working order shall be aboard the vessel for each type of motor or fan used. Net pen space in any compartment shall not exceed 80 percent of the deck area.
Code of Federal Regulations
Footnote(s): 8 Deck height is the height from the ceiling to the floor.