The potential for fuel savings as well as the need to comply with more prevalent and stringent idling regulations continue to make auxiliary power units (APUs) of all types an efficient and effective choice for fleets.
“Fuel costs are a compelling financial incentive for using an APU,” said David Brondum, director of product management and sustainability at Carrier Transicold, Truck/Trailer/Rail Americas. “At current prices, payback periods can be relatively short—about four years for a diesel-powered unit, including maintenance costs. By limiting idling, an APU can also reduce engine maintenance needs and can extend engine life and lead to a higher trade-in value.”
There are a few things fleets should consider when looking into APUs, noted Joe Kirby, director of fleet sales and market intelligence at Bergstrom. “What is the return on investment, including purchase price, installation, operating, maintenance, and fuel costs?” he said. “The biggest benefit is financial savings from reducing fuel consumption and from lower maintenance and downtime expenses. Also, how loud is the system? This may seem like a minor item, but when it comes time to sleep, quiet operation quickly becomes important.”
Steve DeLarosby, auxiliary power unit product manager at Thermo King North America, advised fleets considering an APU to assess how it will reduce engine wear and its preventive maintenance needs. “It’s also important to consider noise levels and vibration during starts and stops,” he related, “and its ability to provide heating and cooling to ensure driver comfort.”
A number of manufacturers offer a variety of diesel- and battery-powered APUs and cab and sleeper heating and cooling systems.
Recently, Carrier Transicold signed an agreement to acquire select IMPCO road and rail transport products, including the ComfortPro APU line from Westport Fuel Systems. The diesel-powered ComfortPro APU is an integrated heating and cooling system with a generator that delivers power for accessories, charges truck batteries, warms the engine, and can be equipped for shorepower compatibility.
The Thermo King TriPac Evolution diesel-powered APU provides sleeper and cab cooling and heating, battery charging with automatic voltage sensing, and has an auto start/stop feature. The APU comes with a 13,000 Btu air conditioning system, a 7,500 Btu heater, and a 65-amp alternator. Also available from the manufacturer is TriPace, an electric battery-powered APU.
Bergstrom, which manufactures battery-operated HVAC systems that provide air conditioning and heat for sleepers, introduced an addition to its NITE product lineup. The NITE Phoenix Space Saving Innovation system is a battery-operated A/C split system designed to fit all sleepers. Also by Bergstrom is the NITE system app for remotely controlling temperature and fan speed, monitoring battery status and runtime, plus troubleshooting and diagnostics.
On the market from Phillips & Temro are Idle Free Systems eAPUs in Series 1000, 2000, 3000 frame rail mounted and Series 4000 behind-the-cab models. The electric APUs feature 1,500-watt, 12Vdc to 120Vac power inverters and heat and air conditioning systems.
Dynasys APUs for most day cab configurations feature adjustable, multi-directional air events for driver and passenger seats and use less than 20 in. of frame rail space. Enhancements to the Dynasys APU for this year include McMillan electric generators, self-tensioning belts, longer life fans, heavier gauge fuel filter brackets, new capacitors for longer runtime and cleaner startup, and upgraded and additional cold control temperature switches for compressor protection.
The Willis Power Systems APU line includes the Premium model, which is available with an air compressor option, and the newer, more compact Willie unit. Both models offer powerful diesel engines, electronic controls with programmable features, and are available with an additional alternator to meet ac/dc power needs.
