Not Too High and Not Too Low

Nick Seraphinoff Jr. knows about the damage humidity can cause. He’s seen it firsthand. Many times. 

In the early 1990s, he was performing HVAC work at a major automotive supplier in Detroit. This company made parts that went into many of the world’s biggest car brands. But the day Seraphinoff was there, these world-class parts weren’t looking so good. 

The company wasn’t maintaining its air-handling units properly, causing high humidity levels and condensation in the facility. The result was that parts and raw materials were rusting where they sat on the shop floor. 

“(The plant) didn’t have adequate fume and exhaust removal systems,” says Seraphinoff, who now works as the Vice President of Project Management at Dee Cramer Inc. in Holly, Michigan. “I don’t think they were throwing the parts out. But I think they were having to add some steps — rust removal and polishing.” 

Humidity control is critical in almost every industry — from manufacturing and farming to medicine and computer technology. Humidity that’s too high can damage infrastructure and critical components, rendering multimillion-dollar machinery almost useless. Humidity that’s too low can cause cracks, static discharge, and in certain cases, explosions. 

Wrong levels can damage equipment
Scott Vidimos, President of East Chicago, Indiana-based industrial contractor Vidimos Inc., has specialized in industrial ventilation contracting for over 50 years. He recalled a client whose plant was falling apart due to an inability to control humidity levels.  

“We performed work at a plant where warm, moisture-laden air was a byproduct of the manufacturing process” due to open hot water tanks, Vidimos says. “The plant did not have sufficient ventilation to dilute the high humidity. Over just a few years, the condensation, which was forming on the building structure, especially during the winter months, caused the building purlins and girts to rust and decay to the point where significant parts of the roof and wall were losing their structural integrity and had to be replaced. The short of it is that they didn't ventilate the building adequately to keep the humidity level down, and it ended up beating the building up.”
Battery manufacturing requires low levels

With its proximity to the Motor City, Dee Cramer has extensive experience installing and servicing HVAC systems for automotive manufacturers and suppliers in the region and across the U.S. Seraphinoff says that as the car industry transitions to electric vehicles, humidity control is growing in importance. EV batteries must be assembled in a dry environment. 

“They have to keep it really dry because of the nature of the materials and the chemicals,” he says. And it's not just EVs that need a low-humidity environment. The multistage paints on modern vehicles won’t adhere to the metal if the humidity is too high. 

And whether it’s used for automotive manufacturing or other industries, machinery is more likely to malfunction if it runs in a humid area. Bearings will wear out quicker and the chances of rust increase. 

Recommended fixes often include installing dehumidifiers, a direct exhaust system or dilution ventilation. Another option is insulating ductwork to prevent condensation inside or outside the duct. 

“Dilution ventilation is like adding water to a strong drink,” Vidimos says. “The water reduces the concentration of alcohol. Likewise, adding outdoor or less humid air to the indoor, humid air provides an average humidity that may be more in an acceptable range.” 

Vidimos says direct exhaust may be the best option.

“Installing hoods directly over humidity-producing processes or enclosing the process prevents the rise of humidity in the operating space,” he says. “The amount of air needed to directly exhaust humid air is typically a fraction of the air needed to provide general ventilation.”

Fixes have trade-offs 
Oftentimes, solutions aren’t perfect, however. If the manufacturing process is contributing to the humidity problems, Vidimos says, plant owners will have to decide what’s most important: fixing the humidity issue or ensuring maximum production.  

“There is a trade-off between first cost and operating cost,” he says. “Hoods or enclosures may be more expensive up front compared with the operating costs of general exhaust or ventilation, which have a higher operating cost.”

But doing nothing is rarely a good option. In the case of the automotive facility with rusting components, Seraphinoff and his co-workers installed mist-removal systems that brought the humidity down to more tolerable levels. 

“They had a tremendous improvement in the environment,” he says. “So between health and welfare and potential damage to the process machinery and the raw materials, they started to see some real benefit.”