Heat stress can be both a physical and emotional reaction to working in high heat or humidity environments. It can also occur from limited airflow in places where the air becomes both hot and stagnant.

Portable air conditioning — or Spot Cooling as it is also known — was created in the mid 1960’s to combat “heat stress” in the workplace. The pioneer of the industrial spot cooler is Denso Corp, the manufacturer of the MovinCool line of portable air conditioning. Their first generation spot coolers were actually designed as high ambient people coolers for workers on assembly lines, in un-air conditioned facilities, and in tight or enclosed places.

Since these units were designed for the industrial environment, they were built to withstand the rigors that they were sure to experience in steel mills, paper mills, and other oppressive manufacturing environments.

These original units had operating ranges up to 115 F. They were designed to take the ambient temperature and humidity and reduce them to a comfortable but healthy level.

Not only did they increase worker productivity dramatically during the summer months, but they also satisfied most Safety Department and OSHA requirements for high ambient job functions.

So effective were these units in the production facility at creating worker comfort that they soon started appearing in offices, hospitals, and in other commercial buildings to combat the localized heat being generated by servers, Personal computers, and other heat generating equipment. Not only did they help overcome the additional heat being generated by equipment, they were also used to supplement the cooling missing from undersized or overloaded building air conditioning systems.

The presence of these industrial spot coolers – dubbed the Classic series - in commercial buildings created demand for an office model with specific design features. As such, additional models called the Office Pro were produced which addressed heat related stress in the office environment. These units were not only designed for the commercial environment, they were also given a more sleek and professional exterior to blend better with their surroundings. Both the color and the exterior were retooled to look like other office equipment.

Industrial applications are often either production or maintenance related. Most manufacturing facilities are un-air conditioned. In some of the more extreme ambient facilities such as steel mills or food preparation, ambient temperatures often exceed and remain at 100º F or above year round.

With upper ambient operation in the 115º to 120º F range, spot coolers provide an element of safety and reduce the danger associated with prolonged exposure to high temperatures. In most cases, the increased productivity associated with these systems provides a payback in months.

Typical uses include:

• Cooling people at work stations or on the assembly line during summer months;

• For high heat maintenance functions in un-air conditioned areas or plants such as during equipment repair or PM schedules;

• For workers who get into enclosed vessels such as storage tanks, airplane fuselages, etc.;

• Inside trucks during loading or unloading.

To compare the use of spot coolers to a permanently installed system, consider the following. A 20,000 square foot production facility may need 100 tons or more

of cooling capacity. If you only employ 25 people within this space, the cost to purchase, install, maintain, and operate such a system would likely result in a much higher cost per employee to operate than a few well placed portables. The long service life (often 15 years or longer) and low operating costs for portable a/c units often provide paybacks in just a few seasons.

Even for manufacturing facilities that are already air conditioned, heat can still be an issue within certain areas. Walls, barriers, partitions, or certain work centers within certain air conditioned facilities often prohibit good air distribution, creating dead zones or hot spots. One way to alleviate this may be to operate the cooling system to its capacity, but this can significantly increase energy consumption.

Portable air conditioning systems can help supplement cooling that already exists within this type of facility or space. By strategically placing spot coolers within these “dead zones”, cooling can be efficiently distributed making workers more comfortable and more productive, keeping the electric bill under control.

The Office Environment Air Conditioned office environments are not immune to the issues of heat stress. Many commercial buildings, schools, institutional buildings, or health care facilities often have spots or whole floors areas where cooling or air flow is inadequate. In addition, pockets of heat from equipment or solar loads from windows can create an extreme environment.

These areas need to be addressed to create a healthy, productive work environment.

A good example of an office hot spot occurs in buildings that house Customer Support Call Centers. Customer call support centers, billing call centers, and warranty centers are everywhere. These support centers are usually regional or national in nature and can be huge, often housing hundreds of representatives.

Often whole floors or wide open areas are packed with people and computers. These floors or spaces, due to networked systems and monitors, will produce concentrated heat. And because building HVAC systems typically distribute air evenly from floor to floor and space to space, Call Support Centers tend to be hotter than other floors within the building.

Many of these companies have discovered that portable a/c systems provide exactly the type of relief they require. It is nearly impossible to balance the cooling provided or the heat load “floor to floor” when a building is cooled by a large chiller system. But by staging portable a/c systems strategically throughout the space, relief can be provided to employees who work in these areas.

No longer just considered an inconvenience, the overheated workplace has been identified as a productivity killer. In today’s business environment, Safety and HR Managers consider heat stress a serious and unhealthy condition. It is a condition that is no longer addressed with just a work break and a bottle of water.

This new-found concern is sure to expand the market for portable air conditioning units in the years to come. FSM