Key component of HVAC systems good for workers

May 1, 2017

When it comes to operating a produce processing operation, there are two issues that are important to consider: maintaining product freshness and maintaining employee comfort. Both of these can be accomplished by effective temperature control and maximizing the impact of the HVAC and chiller systems.

Recent studies have shown that comfortable workers are safer and more productive, which is why keeping those working in a produce processing facility happy during cold and hot months is just as important as the food they are working with.

Andy Olson, marketing manager for Rite-Hite Fans, Milwaukee, said that by moving air more efficiently around a facility you are able to keep people cooler (or warmer) with consistent temperatures in all work areas.

“This stable temperature also helps reduce product waste by eliminating hot zones and cold zones,” he said. “It also helps reduce or eliminate moisture that can cause product spoilage.”

A single Revolution Fan from Rite-Hite circulates a large volume of air up to 85 feet from the fan’s center in all directions for optimum heating or cooling of an area encompassing up to 22,000 square feet.

Depending on the time of season and direction of the fan blades, the fans can have a cooling or warming effect on employees.

Ed Quinn, vice president of Big Ass Solutions, Lexington, Kentucky, notes that as hot air rises to the ceiling in a produce processing facility, the heater runs at greater capacity in order to keep the workers warm at the ground level. Its solutions move air throughout the entire space, including up and over obstructions such as machinery and stacked product.

“By fanning the floor plan with our HVAC system, the airflow pattern ensures air reaches all corners of the building, maintaining consistent conditions throughout and eliminating condensation and stagnant areas where product integrity is a concern,” he said.

MacroAir fans help keep product safe and workers comfortable in a processing facility. Photos: MacroAir

Balancing the air flow

Barry Warner, president of MacroAir Fans, San Bernardino, California, notes thermo-equalization from an HVAC system can be challenging because you need to balance temperature in the space around machinery and other things that block the flow of air, and that can lead to spoilage.

“What we try to do is equalize the space and make the temperature the same throughout so there’s not hot and cold spots by moving the air with some big fans,” he said. “And those can move the air from floor to ceiling and mix it and let you balance the temperature, and it creates enough volume and flow that the air tends to get all around and has enough velocity to move under structures and around things.”

When it’s warmer, these fans can be used to make things more comfortable for employees.

“Indoors, air is supposed to move at about 20 feet per minute, so when you incorporate large fans you can get a comfortable range of 200 feet per minute, a very nice breeze that makes you feel 6-8 degrees cooler, which is significant,” Warner said.

But the fans are just as important for the produce, as air in motion reduces humidity.

“Typically most food will be washed, and the fans keep the air in constant motion, which has a drying effect, which helps reduce mold and moisture buildup, which could accelerate spoilage,” Warner said. “That can extend the life of some of the food.”

Big Ass Solutions has created four fans, based on its original industrial grade product, which can help a produce processing facility also lower heating bills in the winter and keep things cooler in the summer.

“Large, overhead fans help by gently pushing that hot air back down without creating drafts,” Quinn said. “In many spaces, fans can lower heating bills up to 30 percent.”

Fans also play an important role in the safety of the produce. Industrial fans are often used to reduce the water volume and facilitate the drying of washed fruits and vegetables, helping to prevent the growth of bacteria. These fans can be used to blow warm or cool air through the produce, in some cases at quite high pressure.

A high-volume, low-speed fan at work in a food processing facility.

Enhancing HVAC systems

According to those involved in the industry, there are two easy solutions that can be retrofitted to existing HVAC systems in a produce processing facility. Each will enable the facility to operate at a stronger level.

“High-volume, low-speed (HVLS) fans can be installed in the ceiling to help circulate air evenly. These fans can range up to 24 feet in diameter and cover up to 22,000 square feet,” Olson said. “Another relatively new solution is flexible, fabric air dispersion products. These can be used in a variety of applications and have recently started to become popular in growing facilities because of the installation flexibility and the improvement of air movement over traditional ductwork.”

HVLS fans have a number of benefits above improved employee comfort. When used properly, they can reduce energy consumption dramatically, especially in heated facilities, by bringing warm air down from the ceiling and mixing it with cooler air on the ground (destratification). Also, in facilities that have to deal with water on the floor, HVLS fans help floors dry quickly.

“Fabric air dispersion products are custom designed for each application, so air is being moved in the most efficient manner possible,” Olson said. “An added benefit is that they can be laundered as needed for facilities that have to meet health and/or safety directives.”

Both products can improve air dispersion, which can result in increased worker output, lower product waste and improvement to a processor’s bottom line.

The challenge with heat, Warner said, is that it rises, so when heat blows down, it stratosphered in the ceiling.

“A typical processing facility might have 30-foot-high ceilings, and a lot of that heat will collect up there. If you measure the temperature between the floor and the ceiling, it’s typically a 20-degree differential,” he said. “The problem is you are trying to keep people warm at the thermostat level. When you run the fans, you mix the air, and the result is warm air gets to the floor and you should see a 30 percent reduction on heating spend.”

— Keith Loria, contributing writer