LEXINGTON, Kentucky — Field research from the University of California, Berkeley’s Center for the Built Environment and the University of Sydney found that industrial air movement can reduce perceived heat burdens for workers in unconditioned manufacturing facilities.

Researchers monitored 30 factory workers during regular shifts at two manufacturing facilities in Baton Rouge, Louisiana. They compared periods when industrial fans were operating with periods when the fans were turned off.

Workers reported conditions comparable to an environment 10 degrees cooler when industrial fans were running. In addition, 79% of workers said they felt more effective at their jobs with active industrial air movement.

All surveyed workers, or 100%, said having industrial fans operating was important in their workplace.

“Field studies in active manufacturing environments are rare because they’re hard to execute,” said Charlie Huizenga, a founding researcher at the Center for the Built Environment at UC Berkeley. “By monitoring workers under real Louisiana conditions, we found that air movement significantly reduced discomfort and perceived effort.”

The study covered two three-week periods during spring and summer 2025. Researchers conducted the first period in late May and early June and the second in August.

They tracked environmental and physiological conditions along with worker surveys. Oral temperature and heart rate increased as ambient temperatures rose, regardless of whether industrial fans were operating. Sweat rates were lower with fans running during the May and June study period and during August mornings.

The findings come as industrial facilities face challenges managing heat in large, unconditioned spaces. According to internal market analysis from Big Ass Fans, fewer than 20% of U.S. industrial facilities maintain conditioned air.

Big Ass Fans also cited workplace research showing overall productivity declines 1% to 2% for every degree indoor temperatures rise above 75°F. The company said labor capacity can decline by 30% to 50% during peak heat spikes.

For large open plants, full-building air conditioning can be costly. Big Ass Fans said high-volume air-speed solutions operate using 20 to 30 times less energy than conventional air conditioning.

The study also adds field data to discussions about using fans during extreme heat. Current Centers for Disease Control and Prevention guidance advises using fans only when temperatures are below 90°F. More recent World Health Organization guidance recommends fan use at temperatures up to 104°F based on its current understanding of human temperature regulation.

“A single temperature cutoff misses much of what determines whether air movement helps,” said Brian Hilander, VP of Engineering and Operations at Big Ass Fans. “Humidity and radiant heat shape the result, as does the work being performed.”

The research was conducted by the University of California, Berkeley and the University of Sydney and was announced by Big Ass Fans. The company has published a research summary detailing the study’s findings. View it here: bigassfans.com/heat-tax.