Both Technician A and Technician B are correct in their statements, but they are referring to different aspects of the spray booth operation.
Technician A is correct in stating that when more air is entering the spray booth than is being removed, it is considered to have negative pressure. Negative pressure means that the pressure inside the spray booth is lower than the pressure outside. This setup helps to contain the overspray and fumes within the booth, minimizing the risk of spreading them to the surrounding areas.
Technician B is also correct in stating that negative air pressure draws more overspray through the spray booth filters than positive air pressure. When the spray booth has negative pressure, it creates a suction effect. This suction draws the overspray particles towards the filters, improving their efficiency in capturing and removing the overspray from the air.
In summary, both technicians are correct in their statements. The negative pressure in the spray booth helps contain the overspray, and it also enhances the effectiveness of the booth's filters in capturing the overspray particles.