Heading Off Heat Stress

Keep workers safe and efficient with fans and fabric ductwork.

By Bill Murphy and Philip Sloan
From the June 2022 Issue

The summer months are great for baseball and the beach, but not so much for working in a large plant—particularly one that lacks airflow.

Industrial facilities have always had to combat hot weather, but with online commerce driving an even faster pace of shipping, facility managers will be facing a perfect storm of heat-related issues this summer. Workers who feel the heat are prone to mistakes and lapses in productivity, which will inevitably affect the company’s bottom line. And those things are sure to be felt by management in declining revenue.

From an infrastructure standpoint, there are several facility upgrades that can have an immediate impact, such as using high-volume, low-speed (HVLS) fans to provide cooling breezes and fabric ductwork to evenly disperse cool air from the central system to where it is needed.

More Heat, More Problems

Heat stress can manifest itself in a variety of forms. From heat fatigue (workers begin to lose concentration and perform below set standards) to heat stroke (the body’s systems of temperature regulation fail), which requires hospitalization.

An uncomfortably hot facility lowers employee morale and makes them less efficient. In fact, a study by the University of Chicago revealed indoor workers are 4% less productive per 1 degree Fahrenheit above 80 degrees. That means a worker might be 20% less productive in a plant with a temperature of 85 degrees. The Occupational Safety and Health Administration (OSHA) recommends a temperature range between 68 and 76 degrees.

HVLS Fans Add Comfort

Heat Stress HVLS fansWhile adding air conditioning is the best-case scenario, it isn’t always practical. With or without air-conditioning, most facilities will benefit immensely from HVLS fans.

Smaller, floor-mounted fans can be helpful, but their high wind speed and noise levels may cause problems. They also use a relatively high amount of electricity. On the other hand, HVLS fans use relatively little energy and provide a gentle, quiet breeze.

According to the U.S. Department of Health and Human Services paper “Workers in Hot Environments,” a 2 to 3 mph air speed creates an evaporative cooling sensation of 7 to 11 degrees F. To put this in perspective, the effective temperature of an 84-degree warehouse environment can be dropped to 73 degrees by adding a fan moving air at 3 mph. This can make workers up to 35 percent more productive.

Thanks to better air circulation, HVLS fans provide the same benefits in air-conditioned facilities. This increases the efficacy of HVAC systems, allowing for warmer thermostat setpoints to achieve the same temperature on the floor for workers. This helps lower energy costs further.

A technically advanced HVLS fan can move air across up to 31,000 square feet and replace as many as 20 floor fans. HVLS fan blades that provide the right tilt, taper, and twist can help ensure no dead spots exist directly below the fan’s middle to maximize airflow.

Fabric Ducts Spread Air Evenly

Speaking of airflow, traditional metal HVAC ductwork systems are not always the most efficient air dispersion options for large warehouses and plants with open spaces. In recent years, fabric ductwork has become a preferred option. The design of their air-porous and strategic perforations provides even air distribution that virtually eliminates hot and cold spots experienced with traditional metal ductwork. In facilities that offer air conditioning, air-porous fabric ducts and diffusers can provide optimal air delivery while eliminating the potential of condensation forming and dripping on processes and people below.

Not only used in industrial facilities, fabric duct systems are particularly useful in spaces that require temperature and humidity control, including laboratories. The ability to design the fabric system based on the needs of the space provide nearly limitless options for each application.  The light weight and flexibility of their fabric also makes fabric duct systems less expensive and easier to ship than metal ductwork, as well as requiring significantly less time to install.

Heat Stress fabric ductwork
Fabric duct systems are particularly useful in spaces that require temperature and humidity control.

Considering the budget reality of many businesses, these reduced costs are often a big benefit. Unlike metal, fabric ductwork systems are immune to scratches and dents, and since they don’t have resonating properties like metal, they are quieter than their traditional counterparts.

Fabric diffusers that provide 360-degree, air-porous openings are another way to enhance conditioned air distribution. Compared to a metal drop plenum diffuser, a round fabric diffuser brings the occupied space to temperature 22% faster while offering a lower ceiling load, according to an Iowa State University study.

Lower The Heat, Raise Productivity

Improving the workplace environment with HVLS fans and fabric ductwork won’t only make employees more comfortable, it can make them safer and more productive. Distributing air slowly with HVLS fan or evenly with air-porous fabric ducts will help deliver better temperatures and more productive workers.

Before the heat negatively impacts the well-being of workers and directly impacts the bottom line, make a heat stress plan and consider preventative measures.

The information provided herein is provided as a general reference regarding the use of the applicable products in a specific application. It is your responsibility to ensure that you are using all mentioned products properly in your specific application and in accordance with all laws and regulations.

Murphy is the product manager for the Rite-Hite industrial fan division. He has more than 25 years of experience with Rite-Hite, a manufacturer of loading dock safety systems, high-speed industrial doors, and HVLS fans. Murphy has also worked in business development with DuctSox, a division of Rite-Hite that manufactures textile-based, customized air distribution products for the HVAC industry.

Sloan is the director of sales for DuctSox Corporation. Sloan has worked for more than 15 years with DuctSox, a manufacturer of custom engineered commercial and industrial air dispersion products for open ceiling architecture, critical environments, and underfloor applications.

Do you have a comment? Share your thoughts in the Comments section below, or send an e-mail to the Editor at jen@groupc.com.