January 13, 2004
Ventilation systems come in a variety of types for different types of welding processes and varying fabrication facility setups. The emphasis on proper application of these systems and best use of the components used in them comes from an increased interest in cleaner air for the welder.
Breathing is something that many of us take for granted. Most don't give it a second thought—you inhale, you exhale. That's about it.
But recently, and not just in manufacturing, the trend has been for employers to install better ventilation systems and provide better air quality for their workers to improve productivity and the health and happiness of workers.
But employers face a complicated choice with ventilation equipment, as many types are available and many variables must be considered when choosing the appropriate type. The stress of a sluggish economy and the employers' emphasis on getting the best equipment deal only complicate things further.
In any case, more manufacturers are realizing that the purity of the air that their employees breathe is important to their businesses in the long term.
One trend affecting the importance of proper welding ventilation comes from something that doesn't necessarily take place in the workplace today: cigarette smoking.
As more public establishments enact "no smoking" rules, people in general are paying more attention to the air they breathe, according to Bruce Prather, president of Dualdraw, Commerce City, Colo.
"Because of smoking, people are more conscious of what they're breathing; hence, there's more of a question about equipment that can take away what's in the air," he said. "We're more sensitive to what we're breathing."
More specifically, this concern has affected the way welders think about their workspace, said Kevin Stibal, vice president of sales at Environmental Air Solutions, Coralville, Iowa.
"Many people inside the metal fabrication business have grown tired of feeling like a coal-miner every time they leave the workplace," Stibal said. "Welding smoke, diesel fumes, and carbon monoxide all pose a serious health risk to the people with whom they come into contact. Controlling airborne particles maintains the health and morale of employees, as well as the appearance of the facility. Providing adequate ventilation is the solution to this challenge."
Prather also attributes increased scrutiny over ventilation to a rise in lawsuits over workers' health, as well as more specific Occupational Safety and Health Administration (OSHA) guidelines. As a result, he said, more types of ventilation equipment are on the market, aimed toward different specific workplace hazards.
This means more choices for fabricators who are increasingly realizing the importance of ventilation to their success.
"Fabricators today are under increasing competitive pressure to attract high-profile customers and good employees and maintain profitability at the same time. Fabricators are finding that high-profile customers will often assess not only their production capabilities, but also the cleanliness of their facility and the way they treat their employees. Employees are often assessing the same things," said John Reid, president of Great Lakes Air Systems, Clawson, Mich. "People want to work in a clean, bright environment, free of air contamination or pollution that may affect their health. Although the job market has softened up a lot lately, the looming retirement of baby boomers ensures that it will tighten up again soon."
The focus on maintaining and increasing profitability brings about another concern when it comes to welding ventilation, according to Kevin Laporte, president of Uniwash Inc., Harbor Springs, Mich.
"The biggest problem may be from cheap labor in other countries that do not protect their workers from harmful fumes and smoke from production fabrication operations," Laporte said. "American companies exporting the labor necessary to make their products should be required to comply with similar health and safety standards required here.
"Perhaps this would reduce the migration of welding jobs leaving this country," he said. "If corporations were held to the same standards for worker safety and health in, say, Vietnam as in the U.S., it may make decisions for going overseas less easy to make."
As welding employers learn more about the safety hazards in their workplaces, they learn more about how to prevent or eliminate them.
One of the lessons that fabricators learn regarding ventilation is that one system does not fit every fabricator or every process.
"Very few ventilation applications can be approached with a cookie-cutter mentality," Reid said. "Usually each situation or process must be assessed carefully if the ventilation system is to work effectively. There are many factors that must be considered when designing a ventilation system, any of which can result in an ineffective system or an unsatisfied customer. These factors include but are not limited to the type of filtration equipment, blower selection, ductwork design, and hood, or point-of-entry, design. In short, the success of the system depends more upon a thorough understanding of the application and the competence of the ventilation design staff than on what brand name of equipment, ductwork, or hoods are used."
Fabricators also may learn that they're not providing adequate ventilation because they're not properly maintaining their systems routinely.
The upkeep on a ventilation system is a big challenge to welders, according to Hank Sanford, regional sales manager for Micro Air Clean Air Systems, Wichita, Kan.
"Once a filtration ventilation system is installed, the system must be maintained properly to ensure it is operating at design capacity and design efficiency," Sanford said. "The challenge is maintaining a system and to put everything on a regular maintenance system or else they will lose their efficiency."
To help welders with system maintenance, some ventilation system equipmentmakers are striving to bring lower-cost, more user-friendly components into the equipment they offer.
Micro Air, for instance, uses cartridge filtration in a self-cleaning system the equipmentmaker offers. Sanford said this type of filtration ensures that the system is cleaned, but without necessary operator intervention.
Sanford said he's seeing improvements in media filters being used in ventilation systems so that plant managers can rely on the machine to clean itself, therefore reducing the company's maintenance needs and overall labor costs.
Another aid to fabricators when using or choosing ventilation systems is the evolution of filters used for a variety of processes and particulates.
"Better filters and equipment that adapt to various environments [are on the market]," Prather said. "It doesn't sound like a big deal, but it is. Correct filters can remove vast amounts of airborne particulate and odors from around the work force like harmful dusts, smoke, pollen, and mold spores."
According to Sanford, new filter medias can help ventilation systems by targeting specific pollutants caused by particular applications. And when filters are designed for specific pollutants, he said, the filters work more efficiently to remove them and last longer.
According to Laporte, filter media types, construction methods, electrical control features, and exhaust fan technology all play critical roles in the effort to reduce initial costs and operational costs over the lifetime of the application.
"Oftentimes the customer has a solution in mind that we wouldn't touch because our experience has told us that the technology under consideration will fail," he said. "An example of this is in the use of wet-type dust collectors for metal polishing and buffing operations where media-type collectors may be proposed by others. Our experience has told us that wet-type collectors for this type of application are the only viable solution. Then, based on the size of the machine, we incorporate various control and drain features to facilitate trouble-free operation and ease of maintenance."
Another consideration that fabricators make when choosing a ventilation system is how much space it will take up in a facility. Great Lakes Air Systems, for example, offers a system for use with a robotic welding workcell that takes up no floor space.
"The equipment itself has been designed so that it can sit on the top of a robotic weld cell, and therefore takes up no floor space at all," Reid said of the RoboVent FloorSaver system. "It completely eliminates the smoke from a robotic weld cell, filters out the contaminants, and returns clean air to the plant without the concern of fires, with low maintenance costs, and without using any floor space in the plant."
Equipmentmakers interviewed for this article report that fabricators also have been requesting other types of ventilation systems, such as downdraft tables and wet-type dust collectors.
A downdraft table for welding, grinding, and fume removal, although not always the answer to all fume problems and not suited to all applications, can be a user-friendly option, according to Prather.
"In the cases where downdraft tables are applicable, they are user-friendly because you can either sit or stand while welding and you can move parts and stack parts around the table without affecting the table's efficiency," Prather said. "Also, you do not have to move a fume arm—typical with other ventilation equipment—around to where you are operating. This gives the worker more freedom. Downdraft tables will suck smoke and particulates down and away from the operator from a height of 12 to 14 inches."
Wet-type dust collectors also have been popular, according to Laporte, for use in combustible fabrication operations.
"Many applications—metallic sanding, polishing, buffing, any sparking operation—all require wet-type dust collectors for ease of maintenance or for fire safety purposes," he said.
Reid said that he's seeing more and more fabricators choose filtration systems over exhaust-type systems.
"Although these systems are usually more expensive and sometimes present more potential problems, exhausting polluted air to outside the plant results in some major energy costs and is not seen as environmentally responsible," he said. "Manufacturers are looking for filtration systems that are easy and cost-effective to maintain, that stay flexible and make plant layout changes easy, and, at the same time, do not take up any valuable floor space within the plant."
No matter what ventilation system a fabricator chooses, many factors are important. One of the best ways to decide on a certain type is to see it in action.
"My best advice to a manufacturing company is, before you buy filtration equipment, check out other applications similar to your own that have been in place and operating effectively for some time," Reid said.
To meet fabricators' needs for different types of systems, ventilation equipment suppliers have increased in number, which has been both a good and a bad thing, according to equipmentmakers.
With regard to downdraft tables, Prather said that suppliers are fulfilling fabricators' needs because more manufacturers are in the industry than there were five years ago and because these manufacturers offer a wide selection of tables to cover more applications.
But having more suppliers in the industry can sometimes do a disservice to the fabricator, Laporte said.
"In this economy, there are often too many suppliers for the number of opportunities," Laporte said. "The difficulty is in experience. Many suppliers are selling inferior ventilation products or misapplied products due to stress in the market. Customers are at risk of purchasing inappropriate technology based solely on price and may be putting themselves and their employees in harm's way.
"When customers are talked into a technology that is dangerous from fire or explosion and buy that product because initial price is less than the price of product that should be applied, this type of thinking exposes the end user and workers in the vicinity of the machine to undue risk," he said.
Because of these experiences, fabricators are choosing more wisely the type of system to buy, which in turn changes how suppliers need to work with them now and in the future.
"Unfortunately, many fabricators have had bad experiences with ventilation systems. This has resulted in fabricators being much more cognizant of some of the potential problems and increasing their demands on their suppliers in the areas of warranties and satisfaction guarantees," Reid said.
"If ventilation system suppliers are to succeed in the future, they'll have to be able to offer their customers comprehensive satisfaction guarantees for the systems that they provide," Reid said. "This necessitates single-source responsibility for these ventilation systems. Thoroughly understanding an application and making real-life comparisons to systems operating under similar conditions can provide invaluable information that allows a fabricator and a ventilation system designer to come up with the best solution."
Equipmentmakers are investigating new ways to manufacture systems they think ultimately benefit end users.
Dualdraw, for example, has introduced indoor air-quality equipment and is addressing the office environment.
"The acceptance [of indoor air-quality equipment] is picking up as it becomes clear that indoor air pollution is a major problem," Prather said. "It is now known that office air can be as polluted if not more polluted than the air in the fabricating area. Office areas are usually smaller and have less ventilation, which leads to higher concentrations of pollutants. This market, indoor air quality, is compatible with what are currently doing."
Another area of concentration for equipmentmakers is the welder's breathing zone.
"We have created a whole line of downdraft bench ventilation tables and booth back sections to accommodate almost any need to keep the operator's breathing zone clean," Laporte said of Uniwash. "This is in conjunction with a whole line of media and wet-type dust collectors and oil mist collectors available to the market today."
Micro Air has introduced a system that cleans the entire length of the cartridge filter, which Sanford said is important to long-term efficiency.
Another type of ventilation system on the market is an air-to-air heat exchanger system from Environmental Air Solutions that draws in the outside air and forces this air into a series of 11 corrugated tubes. The tubes are routed through a 20-foot-long ventilation duct and then dispersed along the ceiling and down the walls to provide fresh air delivery about 3 ft. from the floor.
"Another way to look at it is heat recycling," Stibal said. "It helps in the removal of airborne contaminants from the air through the natural mechanics of heat. The warm air that is delivered to the floor level through the corrugated tubing is warmer than the surrounding air, creating a natural updraft. By forcing the air movement upward, the system traps all of the smoke and fumes against the ceiling, where no employees can breathe it. The dirty air is then blown outside, but the heat is recaptured and reused as fresh warm air."
Regardless of the type of ventilation system a fabricator uses, equipmentmakers stress that the most important consideration to make when choosing a system is proper application.
"Proper application of the product is everything," Laporte said. "The needs most important to accommodate are customer budget targets, worker safety, and machine configuration to match the need."
The most important factor for fabricators to keep in mind when researching different types and brands of ventilation systems, though, is that one size or type will not fit every application or facility. This is the first step to choosing wisely for end users and is especially true today because ventilation systems are targeting air pollutants more specifically than ever before.
"Long ago, people thought that penicillin would cure almost every sickness," Reid said. "People are beginning to see that it's unlikely that one piece of filtration equipment can be successfully applied to multiple applications, in the same way that penicillin was not successful treating every disease. Much better results can be achieved when equipment is specifically designed for a targeted application."
Practical Welding Today acknowledges the following sources used in this article:
Photograph courtesy of Dualdraw LLC, Commerce City, Colo.
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