The use of forced air supply and exhaust for worker space areas (forced
air supply together with exhaustion system) provide the best ventilation
coverage of enclosures. Equipping the makeup air supply and exhaust
registers with volume dampers to control the rate of air. Volume dampers
are useful with fi eld fl ow balancing the ventilation system. Makeup air
fl ux supply should be somewhat less than exhaust to create the negative
air pressure within the enclosure.