We just completed the tuning and delivery of a high volume, low vacuum extraction skid specified by an alpha-client. They requested a sub-slab depressurization unit capable of maintaining a 0.2″ WC vacuum in an adjacent monitoring point. The feasibility-study established the operating flowrates and induced vacuum. A radial blower on variable frequency drive (VFD) was selected and tuned via a PID loop to eliminate the VOC intrusion into the operating office complex.
The low RPM (therefore low noise), low vacuum blower has eliminated the VI issue and rendered the structure useable to the office staff. The pilot-study results decreased proposed blower size, thereby the reducing electrical inputs of an ill-conceived design.