Heavy/Large object which can't be handled manually or cannot be rotated due to size in painted in Side draft booth, requires a Down Draft Booth.
To facilitate painter to coat object all around by able to move around the object is necessary.
This is achieved in a down draft booth with pump/sludge pit assisted water wash system, below the ground level and also air suction in the downward direction.
This is why it is known as down drat booth. The water washing/scavenging system is added for catering to high paint consumption as in case of side draft booth.
Paint fumes are absorbed in water wall system.