‘Heat Tax’ Places Higher Toll on Spaces Sans AC

LEXINGTON, KY -- Big Ass Fans, a manufacturer of high-volume, low-speed fans, has identified a hidden toll on industrial worksites that can impact worker judgment, lower output, increase turnover, and erode the bottom line.

It’s called a ‘Heat Tax,” and field research from the University of California, Berkeley’s Center for the Built Environment and the University of Sydney, demonstrates how targeted industrial air movement directly mitigates heat burdens in unconditioned spaces where full-building air conditioning is impractical.

“When work feels harder and employees feel less effective, the entire operation carries that burden,” said Leah Larson, CEO of Big Ass Fans. “This study proves how direct industrial air movement protects worker well-being and productivity on the floor.”

Researchers monitored 30 factory workers across regular shifts at two manufacturing facilities in Baton Rouge, Louisiana, alternating periods with industrial fans running versus fans turned off.

Their findings follow:

• Cooling Effect: Workers reported conditions comparable to working in an environment 10 degrees cooler, when industrial fans were operating.
• Worker Effectiveness: 79% of workers reported feeling more effective at their jobs with active industrial air movement.
• Workplace Necessity: 100% of surveyed workers cited having industrial fans running as 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.”

According to internal market analysis by Big Ass Fans, fewer than 20% of U.S. industrial facilities maintain conditioned air, leaving millions of square feet exposed to extreme summer temperatures, during which labor capacity can fall by 30% to 50% during peak heat spikes.

Workplace research shows overall productivity drops 1 to 2% for every degree indoor temperatures climb above 75° F. While full-building HVAC is cost-prohibitive for large open plants, high-volume air speed solutions operate on 20 to 30 times less energy than conventional air conditioning—eliminating massive energy waste while closing the productivity gap.

On the Factory Floor
The study took place over two three-week periods during the spring and summer of 2025—first in late May and early June, and again in August. Researchers tracked environmental and physiological conditions alongside subjective surveys.

Oral temperature and heart rate increased with ambient temperature, regardless of industrial fan status. Sweat rates, however, were lower with fans running during the May and June study period and during August mornings.

One worker described the impact after the study: “The days when the fans were off, were bad days, and tiring days, when I got off work I felt completely drained and dehydrated.”

Navigating Temperature Guidelines
The research results add real-world evidence to an ongoing regulatory debate over fan use in extreme heat. Current Centers for Disease Control and Prevention guidance advises using fans only when temperatures are below 90°F, while more recent World Health Organization guidance, based on the current understanding of how the human body regulates its temperature, recommends using fans at temperatures up to 104°F.

“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.”

To view the full research summary from UC Berkeley and the University of Sydney visit bigassfans.com/heat-tax or cbe.berkeley.edu.

Big Ass Fans are a brand of Madison Air, an air quality solutions provider serving commercial and residential markets.