People often take for granted being able to come in out of the heat. When a summer day gets too warm or a building without air conditioning becomes unbearable, all it takes to cool off is a change of atmosphere.

This is not the case for most factory and plant workers, who spend their days in temperatures upwards of 90°F.

Extreme heat is an unavoidable working condition in manufacturing plants, foundries, dry cleaners, and canneries, where heavy machinery blowing out hot air can heat environments up to 105°, or even hotter.

Workers dealing with high temperatures experience not only discomfort, but substantial risks to their health and safety.

Lance Sorenson at Suttle Manufacturing, Hector, Minn., is one plant manager who knew he needed to find a solution for his overheated workers. As Sorenson explored alternative methods, he decided that spot cooling with the Unico System would do the trick for Suttle.

Effects of heat on workers

The National Institute of Occupational Safety and Health (NIOSH) reports that the frequency of accidents is higher in hot environments than those with more moderate temperature conditions.

Undergoing high temperatures for long periods of time lowers workers’ mental alertness and physical capabilities, leading to an inability to accurately and safely perform a job. Palms damp with perspiration or fogged safety glasses due to humidity also can lead to dangerous mistakes.

Continuous exposure to extreme temperatures can also lead to a variety of heat-related disorders, according to NIOSH. Heat stroke is the most serious problem, when the body’s temperature-regulatory system fails and the body can no longer remove excess heat by sweating. Heat stroke can be fatal, and a victim has little warning that something is wrong before reaching crisis stage.

Other physical repercussions of overheated working conditions include heat exhaustion, heat cramps, fainting, and heat rash.

An employer has responsibilities to ensure a safe workplace, which includes bearable temperatures.

Higher the temp, lower the productivity

While worker safety is the most pressing issue, facility owners and managers should also realize that worker productivity decreases as the temperature increases.

A NASA report shows that a loss in worker output due to temperature begins at 75°. An 85° plant temperature causes an 18% loss in work output and 40% loss in accuracy. Workers in a 95° environment experience a 45% loss in work output and a 70% loss in accuracy.

There are several ways to lessen the potential of employees suffering heat stress on the job:

  • Heat disorders often involve dehydration, as a worker may lose more than a gallon of water through perspiration in day’s time. Break rooms and employee lounges should be equipped with water coolers or bottled water to ensure that workers are drinking enough.

  • Increasing the size of the workforce allows workers to incorporate more breaks into a day while someone else briefly takes over their task.

  • Workers also should be educated on the signs of heat stroke and heat exhaustion so they can recognize that they are ill and need to seek a cooler area.

  • Of course, the most basic way to fight employee overheating is through proper ventilation. Opening doors and supplying standing fans is a start, but the little circulation those methods provide is not enough to combat the steam and hot air pouring from industrial equipment.

However, installing central air conditioning in a massive facility is not always economically or structurally feasible.

Spot cooling

Sorenson discovered that when he began looking into a cooling system for Suttle’s injection molding plant. Jim Smith at Tin Smith Co., the installing contractor consulted for this project, told Sorenson that 50 tons of equipment would be required to effectively cool the plant — equipment that the plant’s roof could not support.

With spot cooling, individual outlets cool each worker, eliminating the need for a central air system. Sorenson chose to install the Unico system, an air handler and mini-duct system with spot-cooling capabilities. The system’s 2-in.-id supply tubing releases cooled air to the immediate area surrounding a worker.

Smith determined the plant needed three 5-ton Unico systems with Lennox condensing units and mounted them on a mezzanine 25 ft above the workstations. The 2-in. supply duct stretches 21 ft from the main trunkline, using 75 outlets to cool 25 workers.

Smith installed economizers with motorized dampers, which draw in outside air to mix with inside air in the spot-cooling system, cooling the air that passes through the outlets.

The spot-cooling system not only avoided placing structural strain on the plant, it avoided placing financial strain on Sorenson. Unico spot cooling came in at approximately one-third of the cost of a central system to cool the entire building.

Sorenson and other plant managers have often asked the question of how to keep employees safe, comfortable, and productive. Spot cooling helps give workers a break without breaking the bank.

Unico can be contacted at 800-527-0896; unico@il.net (e-mail); or www.unicosys tem.com (Web site).

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