Mullins Engineering Co., Inc.

The Plumbers/Steamfitters Union Local 486 in Baltimore operates up to 40 welding booths at a time during apprenticeship training classes. Prior to this project, welding fumes were exhausted through roof-mounted exhaust fans that drew outside air from one wall-mounted louver at one end of the classroom area. When the system was on, other areas of the building would go negative, causing problems with some gas-fired equipment. In addition, the ventilation was not adequate to reduce the health risks associated with welding fumes.

This $236,000 project installed a gas-fired variable speed make-up air unit, and a variable speed exhaust fan ducted to flexible exhaust trunks in each welding booth. As the exhaust from each booth is shut off, exhaust and make-up air quantities are reduced simultaneously, reducing energy costs and maintaining proper pressurization. MEC received a letter of commendation for this project.



Plumbers/Steamfitters Union Local 286 Apprenticeship Training School Baltimore, MD
The Plumbers/Steamfitters Union Local 486 in Baltimore operates up to 40 welding booths at a time during apprenticeship training classes. Prior to this project, welding fumes were exhausted through roof-mounted exhaust fans that drew outside air from one wall-mounted louver at one end of the classroom area. When the system was on, other areas of the building would go negative, causing problems with some gas-fired equipment. In addition, the ventilation was not adequate to reduce the health risks associated with welding fumes. This $236,000 project installed a gas-fired variable speed make-up air unit, and a variable speed exhaust fan ducted to flexible exhaust trunks in each welding booth. As the exhaust from each booth is shut off, exhaust and make-up air quantities are reduced simultaneously, reducing energy costs and maintaining proper pressurization. MEC received a letter of commendation for this project.