Special Delivery: Building Efficient, Green Rigs

Alan M. Petrillo

When Austin-Travis County (TX) EMS needed solutions to address a large electrical draw on ambulance batteries and a cooler interior temperature in Texas’s high-humidity summers, Wheeled Coach’s design engineers stepped up and delivered the goods.

One of the solutions Wheeled Coach developed came in the form of two 80-watt solar panels mounted on an ambulance’s modular body roof, which allowed a rig to be shut off while at a hospital emergency room but still charge the batteries that were powering radios, lights, and mobile data terminals.

The solution to the cooling issue was solved by installing Wheeled Coach’s Cool Bar, a custom auxiliary air conditioning condenser that mounts across the front of a modular box near its top. The Cool Bar not only houses the auxiliary condenser but also provides a base for the ambulance’s emergency warning lights.

Wheeled Coach recently delivered seven ambulances to Austin-Travis County EMS fitted with the solar panels and Cool Bars.

(1) Austin-Travis County (TX) EMS recently took delivery of seven ambulances made by Wheeled Coach that are fitted out with roof-mounted solar panels and auxiliary air conditioning condenser units.
(1) Austin-Travis County (TX) EMS recently took delivery of
seven ambulances made by Wheeled Coach that are fitted out
with roof-mounted solar panels and auxiliary air conditioning
condenser units. (Photos courtesy of Wheeled Coach.)

Bigger and More Efficient

Paul Holzapfel, Wheeled Coach’s national sales manager, says, “Our design team came up with the solar panels on the roof of the box to allow Austin-Travis County to charge its equipment without running the vehicle or plugging into a shore line.” The solar panels also allow EMS to reduce vehicle idling at a scene or a hospital and help reduce the department’s carbon footprint by running greener vehicles.

Holzapfel notes that Austin-Travis County EMS also asked Wheeled Coach for a larger cab than those typically used on a Ford F-450. “We came up with the extended cab, which allowed [the department] to carry additional equipment behind the cab’s captain seats,” Holzapfel says. “We don’t often see extended crew cabs on ambulances, with the notable exception of New York City, which has four-door crew cab ambulances.”

Addressing the need for better air conditioning in the patient box, Wheeled Coach put its Cool Bar on the front of the ambulance. Gaspar Garcia, Wheeled Coach’s regional sales manager, says the Cool Bar improves the cooling capacity of the ambulance by approximately 30 percent, giving about 10 degrees better cooling output in the back of the rig than a typical condenser.

“The common auxiliary condenser is a small box with one or two fans in it,” Garcia says. “Our engineers designed a condenser nearly the width of the module that houses four fans to move the air through the condenser, thereby improving the cooling capacity.”

And because the Cool Bar is mounted at the top-front of the ambulance box, Garcia notes, “It doesn’t take up any extra room yet still serves as a platform for emergency lights and has a nice aesthetic appeal.”

(2) The Wheeled Coach Cool Bar, a custom auxiliary air conditioning condenser, mounts across the top front of the patient compartment and can carry up to seven warning lights on its surface. It improves the cooling capacity of the Wheeled Coach ambulance by 30 percent.
(2) The Wheeled Coach Cool Bar, a custom auxiliary air
conditioning condenser, mounts across the top front of the
patient compartment and can carry up to seven warning lights on its surface. It improves the cooling capacity of the Wheeled
Coach ambulance by 30 percent.

Staying Green

James Shamard, Austin-Travis County EMS’s chief of staff, says that his workgroup of providers started with Wheeled Coach’s base ambulance and then added the elements they needed to perform their jobs well.

“Austin is a very green city,” Shamard says. “The facilities we build are Leadership in Energy and Environmental Design (LEED) certified, and we go to great lengths to use water capture and solar facilities. In looking at our carbon monoxide and nitrogen oxide emissions, we thought we should find a way to reduce them. The first thing we did was downsize from medium duty ambulances to Ford F-450 chassis to reduce emissions.”

Next, Shamard’s group worked with Wheeled Coach to develop the solar system to power equipment that had to continue running when the ignition key was turned off. “They designed two-inch-thick five-amp solar panels on the top of our box,” Shamard says, “that generate a total of 10 amps of power. We need between 6.5 and seven amps to run our mobile data units and other equipment, so we have a bit of leeway there.”

Shamard says that when the ambulance is on the scene and its engine is running, the solar panels are charging the rig’s batteries. “When they’re at the hospital and turn the engine off, the solar panels power a battery conditioner, so the vehicle continues to power the hypothermia cooler, mobile data units, chargers, and other core electrical elements to keep them functioning,” he says. “But there’s no heat or air conditioning running then.” Typically, the crew is inside the hospital for 20 to 25 minutes, he adds.

(3) Two five-amp solar panels on the Austin-Travis County (TX) EMS ambulance order generate a total of 10 amps of power, more than enough to satisfy the seven-amp draw from the mobile data unit, chargers, hypothermia cooler, and other electrical equipment inside the rig that must continue to use power from the ambulances' batteries, even when the ignition is switched off.
(3) Two five-amp solar panels on the Austin-Travis County (TX)
EMS ambulance order generate a total of 10 amps of power, more than enough to satisfy the seven-amp draw from the mobile data unit, chargers, hypothermia cooler, and other electrical equipment inside the rig that must continue to use power from the ambulances’ batteries, even when the ignition is switched off.

Reduced Wear and Tear

Scott Lindsley, Austin-Travis County’s commander of fleet services, says that because the solar panels allow the crew to turn off the ambulance, yet still maintain critical electrical functions, “they keep down the engine hours, the amount of fuel burned, the carbon emissions, and stretch out our maintenance intervals.”

Lindsley says Austin-Travis County EMS is working with Energy Xtreme in Austin, an alternative energy power specialist company, to design a heavy-duty power supply unit for his ambulances. “They’re designing one that can be mounted under the truck, which would give us between 3½ and 4½ hours of constant battery power, much like being plugged into a shore line at the station,” Lindsley points out. “It would allow us to run the air conditioning or the heater if the engine is shut off.”

Lindsley says he expects the power supply unit to weigh around 400 pounds and mount between the frame rails at the back of the truck. “It should give us 6,000 watt hours of electrical capacity from a dry cell battery,” Lindsley observes. “We would like to start installing them in the next six ambulances we’ll be ordering from Wheeled Coach later this year.”

ALAN M. PETRILLO is a Tucson, Arizona-based freelance writer and is a member of the Fire Apparatus & Emergency Equipment editorial advisory board. He served 22 years with the Verdoy (NY) Fire Department, including in the position of chief.


Austin-Travis County (TX) EMS

Strength: 500+ employees, 331 assigned to ambulances as paramedics and EMTs, providing emergency medical services.

Service area: Covers the city of Austin and Travis County with total population of approximately 2.2 million (1.2 million in Austin and 1 million in Travis County). District covers 1,100 square miles of residential, commercial, and industrial properties.

Other apparatus: 66 licensed ambulances, medium duty and Type II Ford chassis vehicles, all made by Wheeled Coach.


Wheeled Coach Custom Ambulances

• 2012 Ford F-450 XLT, 4 x 2
• Extended cab with captain’s chair cab seats
• 186-inch wheelbase
• 6.7-liter engine
• Link Air suspension system
• Heated/remote mirrors
• Keyless entry number pad on cab door
• Custom front brush guard and running boards
• Custom 153-inch-long x 95-inch-wide x 72-inch-high seamless all aluminum modular body
• Module body entry doors equipped with SafePass emergency lock release tabs
• Electric locks for module body doors
• Roof-mounted 12-volt DC/110-volt AC air conditioning system
• CoolBar auxiliary air conditioning condenser
• 1,000-watt Marley heater for patient compartment
• Alsius MD14F portable cooler mounted behind rear attendant seat
• Federal EQ2B electronic siren
• Dual Buell air horns
• Two 80-watt solar panels mounted on modular body roof
Price without equipment: $182,000

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