Downdraft booths. Downdraft booths have vertical airflow. These booths permit greater protection
while allowing more freedom of movement for the painter.
Spray booths range in size from small, bench-type models to huge chambers capable of holding a large
airplane. The basic consideration in determining the size of a spray paint booth is ensuring adequate space to permit the
painters easy access to the top and sides of the object. If the object is transported by conveyor, the booth must be
sufficiently long to allow coating within the time the object remains inside the booth.
Booth exhaust air must be replaced for plant environmental control. The spray booth can be equipped with
filter doors or fresh air inlets to reduce the amount of dust entering the booth. Air should enter the booth at low velocity
(200 feet per minute (fpm) or less) and in the same direction as it is being exhausted to avoid unnecessary turbulence.
Figure 5-14. Operation of Air Transformer