A customer in North Dakota had a large weld fume application that needed dust collectors to clear the air. He purchased (2) ACT 4-48 collectors with 26,000 cfm fans. The system is designed for 7 air changes per hour in the welding area. VFD’s were installed to allow the customer to regulate the air flow as needed. If welding at full capacity, they can run the system at maximum cfm. On days when the number of welders is reduced, the customer has the ability to slow down the fans, still cleaning the air but reducing his energy costs. Later, the customer built an addition to expand their welding area. They purchased another ACT 4-48, rated for 28,000 cfm sized for 7 air changes per hour. A VFD was installed on this system as well to regulate air flow. The customer is very satisfied with the transaction – both working with ACT Dust Collectors and with the quality of the systems.