As the portable air conditioning market grew, so did the mobile air conditioning market. Mobile units could be dispatched to provide cooling for entire buildings or structures, like this one at the University of Tampa.

Do you remember what life was like before the cell phone? This market is not quite 20 years old, yet it has made a profound impact on the way we live and work. Most people can’t imagine living without the instant access that cell technology has provided. The same can be said about the Internet, personal computer, and a host of other products and services that are barely a decade old, but have become integral to everyday life.

The evolution of an industry and its impact on society often make an interesting study. Take portable air conditioning: Introduced to America in 1983 by Denso, a Japanese manufacturer of automotive products, portable air conditioning was first designed to cool workers on the assembly line.

Initially distributed through the traditional air conditioning wholesale supply channel, it achieved marginal success in the early years. American industry had little interest in such an expensive solution, and only a handful of companies adopted this method for worker comfort.

Most sales in those first years consisted of stock orders from the wholesaler. Few end user orders were placed. With excess inventory in stock, wholesaler reorders were scarce. It wasn’t long before some adjustments needed to be made to the distribution channel to jump start sales. The decision was made to establish a network of direct-sales outlets that specialized in portable air conditioning and sold directly to the marketplace.

This proved to be much more successful than traditional wholesale-distribution. Sales to the end user improved, but it was good timing that proved to be the most influential element to the success of the industry. That timing relates to the explosion of the minicomputer that began in the mid 1980s, during this same period.


Large computer centers are environmentally controlled, but many small- and medium-sized computers were relegated to closets and other nooks in office buildings. These spaces were either not air conditioned, or had inadequate cooling for the captured heat loads these systems produce.

Enter the portable air conditioner (spot cooler as it has since been dubbed) as a dedicated a/c system for many of these smaller computer rooms.

Use in the computer room created visibility and really previewed the products’ problem-solving capabilities. Other applications for people and process cooling were soon extrapolated from this exposure. But not all of these new applications had the year-round requirements of the dedicated computer cooler.

Some of these new applications resulted from emergency a/c failures or shutdowns. Others resulted from the higher ambient temperatures in the summer. These shorter-term needs spawned a demand for rentals, so many of these specialty distributors responded by developing rental fleets and a structure to provide immediate access to their customers.

Units are now offered in a variety of models, such as air-cooled, water-cooled, split system, and heat pump configurations. Spot cooling is being used to solve people-, equipment-, and process-cooling problems.


Portable air conditioning providers started setting up shop across the country. By the mid 1990s, nearly all major and most secondary cities had a supplier in the area.

As the market expanded, additional manufacturers with new and different products sprang up. Units were now offered in not only air-cooled but also water-cooled, split system, and heat pump configurations. Spot cooling was being used to solve people-, equipment-, and process-cooling problems throughout the workplace. Portable air conditioning was becoming mainstream.

Note: Portable air conditioners generally refer to units on wheels that can fit through standard interior doorways. As such, they can be deployed anywhere within a commercial building. This tends to limit portable air conditioners to about 5 tons in capacity. Mobile air conditioners are units mounted on trailers or skids, which can be hauled or trucked to a site. Mobile units can be anything from a 10-ton trailer-mounted unit, to 1,000-ton chillers on flat beds.

As the portable air conditioning market was expanding, the mobile air conditioning market was also growing. American business was becoming increasingly reliant upon instant access to cooling for any number of cooling problems, large or small. While portables were ideal for isolated cooling issues within a commercial or institutional building, mobile units could be dispatched to provide cooling for entire buildings or structures. Often, both were used for providing the cooling solution.


Air conditioning and mechanical contractors became the biggest advocates for portable air conditioners. Uses vary depending on conditions. Most contractors rent equipment, as the larger portable a/c providers will inventory all types and models locally, making renting a viable option.

Some contractors also maintain a small fleet of the more popular models for quick deployment. Among the most popular applications are rentals for interim cooling when replacing, repairing, or servicing server or computer room air conditioning units. Many contractors also specify portables as dedicated cooling units for a variety of long-term cooling needs.

But the end user also found spot cooling to be the ideal way to provide equipment protection as well as worker comfort. Customers in industries across the entire spectrum have utilized portables in the office, warehouse, production area, or on the construction site. It’s safe to say there aren’t many, if any, types of business that haven’t used portables to solve heat-related issues.

Companies with multiple locations or national platforms have become particularly frequent users as heat-related problems at one location often are also experienced at others. It is quite common to provide the same products or services to different branches of nationwide companies across the country. For the same reason, national service companies also utilize portables regularly.

When something solves your problem, you come to rely on it. Use it often enough, and it is no longer considered a luxury, but a necessity. Take it away, and you experience hardship. You would find this to be true if you no longer had access to your cell phone, laptop, or the Internet.

Add portable air conditioning to this list. It has evolved to the point where it is no longer just a curiosity; from our standpoint, it ranks in importance right up there with all of our other modern conveniences.

Publication date:06/27/2011