Cooling tunnels maybe fabricated two blowers force ambient or outside air in while drawing the heated air from the parts out the opposite end. Simply passing air over a part results in significantly faster cooling.Why you need paint spray booth ?LAW : There is a statutory requirement under the Factories Act that adequate ventilation be installed wherever spray painting is carried out.SAFETY : Spraying paint may involve fire risk from both solvent and overspray deposits. A spray booth is essential to dispose off both.