The primary reasons fleets are purchasing auxiliary power units (APU) are to save fuel and to comply with driver hours-of-service regulations and an increase in idling restrictions. However, there is a growing awareness that these devices, used to provide energy for functions other than driving the truck, help reduce driver turnover and its associated costs.
The reason for this is that APU systems help improve the quality of a driver's life on the road, says Eduardo Andrade, business manager-special products for Carrier Transicold. With an APU, a driver can reduce his truck engine idling, which decreases engine noise and vehicle vibration.
“APU engines are much quieter than truck engines so drivers can get more serene rest per day, for reduced fatigue,” he says.
In addition to complete climate control, APUs perform other functions, including providing power to run onboard electrical equipment such as computers, DVD players, video games, and appliances.
Externally, APU systems look quite similar, but there are distinctions, Andrade says. For example, Carrier Transicold's ComfortPro APU uses a hybrid diesel-electric architecture to provide both air-conditioning and heating for the sleeper cab, 110/120-volt AC household current, truck battery charging, truck engine warming, and optional ability to tap into shore power. A diesel engine runs a generator that powers all electrical components, including the air-conditioning compressor.
Other APU systems will typically employ a belt-driven compressor and other approaches to heating, such as coolant circulation or a separate fuel-fired heater. Some systems have inverters that use truck batteries for powering electrical loads in the sleeper.
“APUs provide drivers with additional in-cab comfort and convenience while on the road,” says Andrade, “which can help fleets in terms of driver recruitment and retention. We know of fleets that offer drivers a choice of a sign-on bonus or a truck equipped with an APU.”
The driver turnover rate for long-distance carriers far exceeds 100%, he says. “The cost on a per-driver basis to recruit, hire, and train can be $5,000 to as much as $10,000.
Along with the other consideration in selecting an APU, driver retention should become part of the analysis, says Andrade. So should residual value.
“The credibility of an APU vendor and its reputation in the marketplace for reliability and service support are key elements in helping determine the residual value of an APU-equipped truck when a fleet is done with its lifecycle,” he says.
Like any component, an APU can add or detract from the value of a truck when a fleet goes to trade or resell. “APUs from suppliers known for reliability and after-sale support command a more meaningful amount of money.” says Andrade. So do trucks with a low idling history.