Given their expansive footprints and high ceilings, manufacturing plants often face a variety of environmental control challenges, particularly as it relates to temperature control and energy efficiency.
During the summer, facilities may become uncomfortably hot. Meanwhile, cold winter months may lead workers to shiver at floor level as heated air accumulates in the rafters. Because of this, a growing number of decision-makers are adding high-volume, low-speed (HVLS) ceiling fans, often integrating them with heating, ventilation and air conditioning (HVAC) systems to increase employee comfort and productivity while simultaneously lowering energy use.
Heat Stress Types and Causes
Temperature control problems are most obvious during summer months. Rising ambient outdoor temperatures combined with heat caused by manufacturing processes and a lack of cool air can lead to a variety of types and levels of heat stress. The mildest forms are heat fatigue, where workers begin to lose concentration and perform erratically, and heat rash, which occurs when sweat ducts get plugged and skin becomes agitated and painful. Heat stress may also cause heat cramps, typically in the larger muscles used during work like back, arms, legs and abdomen. Dehydration and electrolyte imbalance caused by prolonged sweating are typically causes.
Heat exhaustion, heat syncope (fainting) and heat stroke are among the most serious types of heat stress disorders. Heat syncope usually happens due to a pooling of blood in the lower extremities and dilated vessels of the skin, leading to low blood pressure and sudden unconsciousness. Heat exhaustion can occur on its own or as a prelude to fainting. Common symptoms are similar to heat fatigue, but more severe, including diarrhea, nausea and disorientation. Heat stroke is the most serious heat stress disorder and can be life-threatening. It occurs when the body’s systems of temperature regulation fail and body temperatures rise to critical levels. Hospitalization is a must for anyone who suffers a heat stroke.
Processes in manufacturing facilities often involve massive amounts of heat, whether it be due to welding, cutting or grinding materials. This heat, combined with the hot summer weather in an enclosed space can create a dangerously hot work environment. Implementing HVLS fans and integrating them into a building management system (BMS) with a central fan control panel, can help to create a cool, safe environment for manufacturing facilities employees to work in.
A Better Workplace Environment, Year-Round
The goal at any operation is to create a comfortable and productive workplace environment. Although HVAC systems are increasingly prevalent, there are still many manufacturing facilities without air conditioning — which potentially makes them both uncomfortable and unproductive during hot weather.
The gentle breeze created by HVLS fans can mitigate this problem. According to the U.S. Department of Health and Human Services, a modest 2-3 mph air speed can create a cooling sensation of 7-11 degrees F. That means adding an HVLS fan operating at that level to a facility with a base temperature of 84 degrees F will effectively bring the temperature down to 73 degrees F. Studies have shown that this temperature reduction can make workers as much as 10-35 percent more productive.
Some facilities attempt to achieve this effect using traditional high-speed floor fans. Unfortunately, smaller, floor-mounted fans are only helpful in limited areas, as their high wind speed can cause problems, while their noisy operating level introduces another stress-inducing factor. Not to mention the high amount of electricity they use. HVLS fans eliminate this clutter, since they can move of air over an area up to 22,000 square feet — an area that it would take 10 to 20 floor fans to cover.
HVLS fans are also a boon for air-conditioned facilities. In summer, the breeze created from an HVLS fan can typically allow up to a 5 degree F increase in thermostat setting with no change in employee comfort. This equates to an electric bill savings of 4 percent for each degree, resulting in an annual savings of 20 percent.
These effects are even more noticeable in winter, as HVLS ceiling fans mitigate the rising heat effect by gently moving the warm air near the ceiling back down toward the floor where it is needed. The air reaches the floor below the fan where it then moves horizontally a few feet above the floor before eventually rising up to the ceiling where it is cycled down again. This process, known as destratification, creates a more uniform air temperature with likely only a single degree difference from floor to ceiling.
HVLS Networks and BMS
Often, facilities have ambient sunlight or temperature-effecting operations, such as loading docks, in one area of the building and not others. Due to these temperature-altering features, fan speed, timing and various other settings may need to change by location – creating a challenge to manage different groups of fans across large manufacturing facilities.
Fortunately, the most advanced HVLS fans can be linked into networks of up to 18 fans and run off of a single controller. That controller allows for independent speed adjustments, scheduled start/stop times and the ability to start/stop based on preset temperature settings. HVLS fan networks allow manufacturing facility managers are able to strategically maximize building comfort and enable fans to circulate air in dead zones, prompting them to run only when needed.
Using an optional Ethernet port, these systems can be accessed remotely via a smartphone, tablet or other mobile device. Additionally, they can be programmed into a BMS and connected to other infrastructure equipment, such as a thermostat, which can signal the optimal times for fans to turn on and off, thereby further reducing energy usage.
A Healthy Decision… With Bottom-Line Impact
The use of HVLS fan networks has gained increased attention as a practical and affordable solution to improving air movement, reducing heat stress and creating overall better environmental control. These fans, networked together and (ideally) into a BMS, are recognized as a valuable supplement to help manufacturing facility managers control energy costs and improve employee comfort and productivity.
Creating a more comfortable, healthier workplace clearly signals that a company's management is willing to invest in employees and is serious about their safety — as well as the integrity of the products it manufactures. All can have a direct and significant impact on the organization's bottom line.
Andy Olson works with Rite-Hite Fans.