Large Aircraft Inserts
In this booth, the filter wall is located at the rear of the booth (upper right). Replacement air is introduced into the booth through very large plenum doors at the front of the booth (lower left). This design provides the most consistent laminar airflow possible in a booth of this size. The tail of the plane is located at the rear of the booth.
Notice that the difference between the overall center height and the sidewall height is significant. This reduces most of the paint booth ceiling to just over the top of the aircraft fuselage. The airflow in the booth is sized for the lower cross-sectional area. This airflow is often 50 to 65 percent of the airflow required in a paint barn. This helps control the laminar nature of the paint booth airflow. The difference in the overall height and the sidewall height also allows for significant structural advantages. This difference is often 25 to 35 feet in depth, and if a truss is designed using that depth of section, the truss is incredibly rigid.
Notice from the figure that the two main trusses require that a lateral truss support it from the sides. This geometry means that only four footings are required to support the main structure. Two are at the rear behind the filter chamber. The other two are on each side of the booth under the transverse truss. The front end of the two main trusses is cantilevered to the face of the booth.
One of the main design efforts for a paint booth is the location of the mechanical equipment. In this case, the low roof of the booth makes an ideal place to store the mechanical equipment. There is plenty of headroom and a wide area available.
Even off-the-shelf air make-up units can be arranged to provide the smaller amounts of airflow that this booth requires. The combined airflow is then ducted to the front plenum doors for distribution into the paint booth. The weight of the mechanical equipment and its access platforms are carefully located to be as close as possible to the stiff and stable structure of the filter chamber.