Lou Kren Lou Kren
Senior Editor

The Real Cost of Shop Air Quality

January 29, 2019

Fumes and particulates populating the air in a manufacturing environment are quite different from those present only a few years back. Metalformers and fabricators shape and assemble evolving grades of materials featuring new mixtures of elements. These materials, coated with newer formulations of rust inhibitors, surfactants, soaps, oils and more, release fumes and particulates during forming, cutting, heating and welding operations, with machinery adding mist to the mix.

Today’s air-cleaning systems for metalformers and fabricators employ variable-frequency drives as well as other technologies to better handle exotic dust and fumes and keep maintenance and energy expenses in line.

Air-quality systems strive to stay ahead, with manufacturers developing unique equipment and filters to combat the dirty air. To win the battle, both in the air and in the pocketbook, a manufacturer should closely examine its air-handling needs, and look beyond initial system cost to the total cost over the life of a system.

That’s the word from Mike Meyer, executive technical director at RoboVent, Sterling Heights, MI, a manufacturer of air-cleaning equipment, including systems to extract oil mist and weld fumes. It also supports educational efforts to help metalformers and fabricators understand the total cost of ownership related to dust collectors and industrial ventilation systems.

New Breeds of Dust and Fume

Education efforts stem from introduction of more unique mist components and particulates in manufacturing environments over the last decade, according to Meyer.

“Materials welded and formed today differ greatly from those of five or 10 years ago,” he says. “Processes feature increase speed and throughput, and, often, manufacturers employ coatings to move material through presses and other machines smoothly and as quickly as possible. These parts, with oils, paraffins, surfactants and other coatings, are processed and welded, which releases dust and mist into the environment. We are not just collecting weld fume anymore. We are collecting ‘weld fume plus.’ Because it differs in composition from only a few years ago, it strains air-quality equipment and filtering mechanisms.”

Substandard Air Cleaning Has Serious Costs

Frequency of filter changes correlate directly with the evolution of mists and particulates, according to Meyer.

“Because of the different fume and particulate, filters do not last as long,” he says. “Using traditional techniques filters may last six months now, whereas before they lasted for a year or two. On top of that, filters often collect hazardous material and must be disposed of via a hazmat process and transported to hazardous-waste landfills.”

Newer material grades and coatings introduce unique dust hazards and can play havoc with filters. A correctly designed air-cleaning system and improved filter technology help combat these developments.
Meyer and Frank Cea, director of marketing communications and development at RoboVent, provided an anecdotal cost breakdown of air-cleaner filter replacement. With filters typically priced at $1 or more per ft.3/min. a 10,000-cfm unit already sets a manufacturer out $10,000 for a new filter. Add labor and disposal, and total filter-replacement cost can reach $15,000 or more, especially if hazardous-waste removal and disposal are needed. Replacing filters two to three times more often than previously typical quickly escalates air-cleaning expenses.

But dirty filters are not an option. Clogged filters force air-cleaning systems to work harder, leading to energy inefficiency, diminished effectiveness and more. That means extra costs for maintenance and repair, and higher electricity costs. Uncaptured dust settling in ductwork heightens the risk of combustion, while cleaning ducts often entails paying specialized contractors to remove the dust. In addition, inhouse maintenance personnel, instead of focusing on maintenance and repair to keep processes and equipment running smoothly, spend time and resources on air-handling issues. Ineffective air cleaning also leads to higher lighting and heating costs, according to Meyer.

Then there’s the human toll. Studies have demonstrated the connection between air quality and productivity in commercial environments. Improving air quality has been linked to reduced error rates, increased output and a significant reduction in absenteeism. A recent study from the National Bureau of Economic Research revealed a 4.2-percent improvement in worker productivity when reducing indoor-air-pollution levels by 10 ppb. Another study shows that poor indoor-air quality causes six additional lost workdays per year for every 10 employees.

Indoor-air quality also affects employee recruitment and retention, according to Meyer.

“Clean indoor air in metalforming and fabricating operations assist in attracting and keeping good employees—doing so creates an environment that people want to work in,” he says.

And, not only is clean air good business, it’s the law. A host of standards and guidelines regulate and support workplace air quality, and manufacturers must stay current with ever-changing regulations. Liability awaits those who slack in such efforts, with fines, lawsuits and other sanctions a virtual certainty.

Advanced Systems Minimize Expenses

By closely examining their air-cleaning systems with the help of reputable providers, metalformers and fabricators can fully determine true costs—considering the expenses detailed above—and select new systems or upgrades that provide a clean, healthy environment and more productive shop floor without excessive costs for filters, energy use, maintenance and repair.

Newer technology enables these improvements. For example, variable-speed drives in air-cleaning systems provide energy-efficient options for supplying needed power. A standard industry formula, the air-power equation, provides a rough measure of the cost to run a motor for air flow. The formula: 40 x brake horsepower x number of hours operating the fan x cost per kwh. Here, the variable is brake horsepower, explains Meyer.

“You can vary brake horsepower using a variable-frequency drive (VFD),” he says. “A VFD uses just enough brake horsepower to effectively capture the dust.”

Thus, VFDs decrease energy costs while reducing strain on system components, making them game changers, according to Meyer, who notes that RoboVent employs VFDs on 95 percent of its systems, save for the smallest units.

“Instead of designing an air-cleaning solution for a worst-case scenario where it works way too hard when filters are clean and costing a company money due to high electricity usage, or running a fan so slowly that it only captures dust well at the beginning but not as the filters fill up, a VFD offers the ideal setup,” Meyer says. “The proper design for cost control as well as employee protection: a VFD that always pulls the correct amount of air to capture contaminants.”

Filters also benefit from technology improvements, which deliver increased filter life.

“For example,” Meyer explains, “inert microscopic materials injected into ductwork absorbs oils and certain chemicals so that they don’t adversely affect the filtration media.”

Pays Off Over Time

Ultimately, manufacturers must consider the total lifecycle cost of air-cleaning equipment, including the capital cost as well as expenses as detailed above, according to Meyer, who notes that doing so yields a solution that pays for itself through maximized benefits and decreased expenses over time. The most effective approach, according to Meyer: meeting with all stakeholders during system design.

“We want to talk to all stakeholders when we put a proposal together,” he says. “The owner, maintenance personnel, the plant manager, etc., all have differing perspectives. Involving a variety of people provides a broad swathe of knowledge and concerns, and gets everyone thinking of total cost of ownership, including the initial buy as well as expenses—including hidden expenses related to employee wellness and morale—over time.” MF

Industry-Related Terms: Forming, Run
View Glossary of Metalforming Terms


See also: RoboVent

Technologies: Welding and Joining


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