Air Distribution Specifications

The components of the vehicle must be designed in such a way to allow proper cleaning to maintain the original design intent.

Bulkhead  - An air return bulkhead shall provide a minimum of 350 square inches return airflow area, be positioned a minimum of four inches out from the front wall and up a minimum of six inches from the bottom of the floor. For duct or T-type floors, measure to the lowest portion of the floor. Bumpers must be installed in the bottom open area to prevent entry of the load. When the bulkhead is the solid front (pressure) type, it should have top side openings of 30 - 50 square inches total to allow top air to mix with the bottom return air. (The top side bulkhead openings allow adequate airflow to the thermostat for temperature control, should the trailer airflow be interrupted by improper loading or load shift.) Also, bulkhead supports attached to the trailer front wall must have sufficient cross-flow openings (minimum 30 percent) to provide uniform air return across the entire width of the floor.