Christian P. Koop

Those who have been around for a while probably remember when fire apparatus did not have air-conditioning (a/c).

That was when most fire trucks still had open cabs in the rear or jump seat area. The requirement to fully enclose cabs for safety reasons also created the need to air-condition the cabs, particularly for those in the warmer climates. In these areas, a/c service and repair for emergency vehicle technicians (EVTs) is pretty much a year-round requirement compared with those in the north, who may only need it in the summer months. Depending on the vehicle type and where and how the a/c evaporator and condenser are installed and mounted, access and service can be time-consuming and difficult. Those involved in developing specifications for new apparatus should keep in mind the importance of designing a/c systems from the onset to make it easier for EVTs to service and repair them. This will ultimately result in reduced downtime and save dollars over the long haul-a very important item with today's tighter budgets. In this article, I will briefly cover some of the history involving development of refrigerant and automotive a/c systems. I will also discuss several service and repair tips for technicians to identify common causes of a/c system failures.

Origins

Today there are many different types of refrigerants for different applications. The first person credited for developing a process to synthesize chlorofluorocarbons (CFCs) is Frederic Swarts in the late 19th century. The refrigerants in use at this time were very dangerous as they were flammable, highly toxic, and deadly. To find a better refrigerant, Charles Kettering, from General Motors, formed a team that developed a more stable, nonflammable, moderately toxic refrigerant in the late 1920s using Swarts's process. Many may remember Freon 12 or R-12 (dichlorodifluoromethane). This is the refrigerant General Motors and DuPont jointly produced and patented that was used in a/c systems in automobiles, trucks, and various other refrigeration applications for more than 50 years in the United States and many parts of the world. This refrigerant was eventually determined to deplete the atmospheric ozone layer and was phased out in the mid 1990s under the Montreal Protocol. It may still be in production, although illegal, in some countries. It has a global warming potential (GWP) of 2,400.

Although GWP figures are known to be controversial, I think they are worth mentioning to provide a perspective on the environmental problem associated with these refrigerants. R-134A (tetrafluoroethane), which is also harmful to the ozone layer, has a GWP of 1300, and has a 10-year life span, replaced R-12. Because of its high GWP, there is a worldwide push to phase out any refrigerant that has a GWP higher than 150. There are various refrigerants that may replace R-134A. From what I understand, R-1234yf (GWP of 4) may end up being the refrigerant of choice because of its very low GWP and much shorter atmospheric life. In Europe, some manufacturers are already using R-1234yf. In the United States, the Environmental Protection Agency (EPA) will require the phase-out of R-134A over the next few years. Currently there are several replacement refrigerants being proposed to replace R-134A, and it is expected that by the 2021 model year, all vehicles in the United States will be sold with a replacement refrigerant.

Most EVTs won't have to worry about these major changes for some time but should keep in mind that there are other refrigerants sold as cheaper "alternatives" t

Sentence 14.1.9.1 in National Fire Protection Association (NFPA) 1901, Standard for Automotive Fire Apparatus (2009 ed.), states that each driving and crew area seating space shall be a minimum of 22 inches wide at shoulder level.

BY BILL ADAMS

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Robert Tutterow, author of this magazine's "Keeping it Safe" column, wrote three recent pieces describing cramped seating conditions in fire apparatus and, in particular, custom cabs. He cited technical studies, some starting in 2006, by professional organizations, fire departments, and government agencies, that resulted in recommendations and a proposed change to NFPA 1901 to increase the minimum seat width to 28 inches. Even with a major compromise, the NFPA rejected the proposed change. Purchasers should read Tutterow's January 2015 column-or forever keep mum about cramped cab seating.

Several apparatus manufacturers (OEMs) progressively addressed fully enclosed firefighter seating long before the NFPA nixed riding the tailboard. Manufacturers including Mack, Pirsch, Seagrave, American LaFrance, and Buffalo started introducing three- and four-door fully enclosed cabs on custom chassis in the 1930s. In the late 1960s when working in his family-owned apparatus manufacturing business, Jim Kirvida was instrumental in developing a line of fully enclosed crew cabs for apparatus on commercial chassis. The first, on a Ford C-Series, was delivered to St. Paul, Minnesota, in 1968.

Mack built its fully enclosed sedan cab in 1935. This 1939 sedan cab, built "around" the fire pump, was a common configuration. Some manufacturers are reintroducing variations of the concept today. (Photo 1 is a delivery photo courtesy of Harvey Eckart; photos 2-19 courtesy of CustomFIRE.)

In 1982, Kirvida formed his own company, Custom Fire Apparatus, Inc., continuing his design and development of fully enclosed crew cabs built on apparatus of his own manufacture. From the January 1984 edition of "Custom Concepts," his newsletter, "Many fire chiefs had complained for years of poor design and cramped quarters in vehicles transporting as many as six firefighters." They still are. One solution to cramped seating on today's apparatus has been around for almost five decades. It is a free-standing crew cab enclosure.

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Nomenclature and Disclaimer

In this article, commercial chassis are conventional (engine ahead of the cab) designs with factory-supplied two- or four-door (sedan) cabs used by numerous industries. The fire service uses them with OEM modifications to meet NFPA 1901 criteria. A custom chassis is one where both cab and chassis are designed for fire service applications. A crew cab module (aka a crew cab enclosure) is a free-standing structure separate from the chassis cab. Specifically designed to carry firefighters, it can be mounted on either style chassis.

There is no intent to den

CMC Rescue's DualCom™ radio harness features an intuitive design that comes from years of in-the-field experience as well as customer feedback. The ergonomically designed DualCom provides all-day comfort.

Made of Cordura® nylon, this lightweight harness offers quick, organized access to personal communication equipment rescue responders need on the job. The harness's open-air 3D mesh back and breathable internal mesh on the inside face, bottom, and side of the main compartment deliver maximum airflow. Two individually sized and adjustable pockets accommodate a wide range of radios from compact to large, including the Bendix King. Alternatively, the second radio pocket can be used for a GPS unit or other device. This intelligent harness keeps a variety of communication devices and field necessities at hand and includes a side-zip pocket to accommodate cellphones up to 6.5 x 3 inches. www.cmcrescue.com, 800-513-7455

Gear Keeper retractable RT4-4465 flashlight attachment tether offers an aluminum carabiner featuring gentle extension and retraction with an arm's length 22-inch strain-free reach. Firefighters need only grab their light, use it, and let it go; it will always be right where they need it.

When the situation requires it, the RT4-4465 employs a patented Q/C release system enabling the flashlight to be easily detached for use at a moment's notice. The RT4-4465 flashlight retractor joins the broader family of Gear Keeper flashlight retractors. The Gear Keeper flashlight retractor line offers snap-clip retractors for small (4AA-2C) and medium (3C-8AA) flashlights and carabiner, brass, and stainless steel clip retractors for large (3C/4C rechargeable) flashlights. Options include threaded stud-mounted stabilizer kits that eliminate the annoying swinging and dangling associated with firefighter flashlights. www.gearkeeper.com, 888-588-9981

Impact Power Technologies (IPT) Lithium Polymer Lifesaver Series™ batteries deliver for more than 40 hours. More power means consistent communications and safer first responders, as well as competitive replacement costs and more savings overall.

The IPT proprietary Lithium Polymer chemistry and exclusive battery management system (BMS) makes the extended life possible. IPT has ramped up the milliamps capacity to 4,700, thereby increasing the power more than 30 percent. IPT guarantees 900 charging cycles, no memory effect for faster charging, batteries that maintain 80 percent of rated capacity for two years, OEM charger compatibility, and OEM warrantees that remain in full force. www.impactpowertech.com, 772-210-2286

OTTO 500 high-temperature fire speaker microphone is designed to continue functioning even in extreme situations. It is tested to function for more than five minutes at 500°F using high-temperature materials in the case, cable, and strain relief.

With full immersion capability in one meter of water for 31 minutes and debris protection, including a removable grille and replaceable debris screen for easy cleaning, the OTTO 500 is a suitable choice for firefighting environments.

The following are products debuted at FDIC International 2015. For complete coverage of the show, visit http://www.fireapparatus.com/fdic.

Hurst Jaws of Life® eDRAULIC 2.0 R 421E2 telescopic ram extends to 53 inches with a maximum pushing force of 28,600 pounds. The newly designed, sharp claws at both ends of the ram can be rotated 360 degrees and the ergonomically designed star grip permits tool actuation from almost any gripping position. The ram weighs 41.9 pounds and comes with two Li-Ion rechargeable batteries and one charger. www.jawsoflife.com, 800-537-2659

Scott Safety X-Series X380N thermal imaging camera is NFPA 1801 compliant. The X380N thermal imager, powered by ISG technology, features exclusive hot and cold spot tracker technology, which immediately identifies the hottest or coldest area of a scene for better informed decisions. All thermal imagers in the X-Series offer high-resolution detection, superior image quality, Intelligent Focus™ to clearly see at temperatures above 2,000°F, and transparent colorization. http://www.scottsafety.com, 704-291-8300

Pierce Command Zone system displays its real-time data and diagnostic information through a full-featured and full-color seven-inch industrial-grade touchscreen monitor. Apparatus vehicle drivers benefit from touchscreen "at-a-glance" views of initial diagnostics to ensure that "all systems are go" prior to vehicle departure. Screen views include important safety information such as "do not move truck" warnings and seat belt system usage. Optional capabilities include an integrated GPS mapping system that seamlessly directs the driver to any emergency scene. Other available capabilities include tire pressure monitoring, collision mitigation, and outrigger placement if operating an aerial. www.piercemfg.com, 920-832-3000

Paladin Caselight CL10K offers up to 10,000 lumens of light for up to seven hours on battery power and can be deployed in fewer than 20 seconds. Weighing just 32 pounds, the Paladin Caselight CL10K is ready to go anywhere first responders need light-from the floors of a blacked-out high-rise to a late-night traffic collision on a remote stretch of road. Applications range from arson investigations to vehicle extrications, traffic control, and more. www.paladinprotect.com, 888-394-6765

Holmatro 5000 series spreaders offer weight reduction without compromising spreading force and spreading distance. Two models are also available with Greenline battery technology for increased freedom of movement. Within this new series, the SP 5240 CL spreader weighs 21.8 pounds. Like all other models, the SP 5240 CL has been tested extensively on the latest car prototypes. Other features include effective spreading tip profile for perfect grip, new ergonomic carrying handle design to increase operator comfort in various working