Problem:

Whether you’re a truck fleet or a trailer factory, welding is usually a part of the shop picture. Fleets that run their own maintenance shops often call upon a welder for frame repairs or to make other fixes requiring an acetylene torch to fuse metal together. It’s no different in a trailer factory, either, where welding is a crucial step in fusing together essential components of a trailer’s structure.

But the fumes and gases emitted during welding can be hazardous to a person’s health, so maintenance shops and/or factories where a lot of welding takes place typically rely upon heavy-duty exhaust fans to vent vapors.

For shops and other welding facilities located in notoriously wintry states such as Minnesota, however, venting systems end up bringing in super cold air from outside the building. This not only causes discomfort among personnel but also boosts the facility’s heating bills.

“That’s one of the big problems with a traditional venting system; all of the building’s heat gets drawn out while letting all the cold air in,” explains Doug Feela, maintenance director for Felling Trailers.

He says Felling’s air purging system, located near the ceiling, allowed an enormous amount of heat loss.

Solution:

To solve this two-sided problem, Felling enlisted the services of KVA Engineering, an air handling company located in Corcoran, MN. KVA installed three “air exchange” ventilation system units at Felling’s facility, with the first installed in 2008 and subsequent systems installed in 2009 and 2011 as part of plant expansions.

Feela says that because welding fumes are hot and hot air rises, the air exchange system is located near the ceiling with high efficiency exhaust fans designed to capture welding fumes and gases at their source and remove them so that they never enter the welders’ breathing zones. Use of welding guns also help to extract fumes from the air, he notes.

Feela adds that ducts are evenly distributed throughout the welding bays so the ventilation system pulls the fumes and hot air away from wherever a welder is working. Consequently, it keeps the air quality clear.

Once the welding fumes and hot air are captured in the ductwork, they are transported to the filter unit and fan at a rate of about 3,000 ft. /min. They are then pushed through a high efficiency cartridge filter with a 99.9% efficiency rate, thus returning clean air back into the plant. After all of the air is cleaned, it is recirculated through the ductwork into the welding bays.

The system pulls 100% of the welding fumes out of the welding bay and exchanges the air within 10 min., making it extremely efficient. Not only does this process keep the air nice and clean, it provides a cleaner work environment and improved air quality for workers—all while minimizing heat loss.

“Installing this air exchange system in our facilities was well worth it; there is a night and day difference,” notes Feela. “The air is recirculated at high speed to cleanse it of fumes, yet the heat doesn’t go away; we maintain about 61 deg. F in the plant. While the ‘air exchange’ systems were initially costly, we built up significant savings from the heat retention as time went on.”

He adds that there’s also the huge benefit of keeping personnel comfortable, and they don’t need to wear heavy jackets and gloves like before to stay warm during the workday. “We’ve found that it’s made them far more productive,” Feela says. “So we’ve realized several different sets of savings versus our old exhaust fan system.”