As fuel cost rise and more states and municipalities regulate idling time, finding ways to provide creature comforts for drivers with the engine off is more important than ever.
Truck drivers generally idle trucks during required rest periods to provide heat, air conditioning or electricity for onboard creature comforts in cabs. In the past, idling engines was the only way to keep a cab and driver warm or cool, but these days there are new technologies that are designed to provide key-off power for amenities.
Breaking the habit
“The primary reason to minimize engine idling is to save fuel,” says Ed Saxman, product manager, drivetrain for Volvo Trucks. “Even though diesel engines idle at lower levels compared to gasoline, these days with the increased cost of diesel fuel, idling can add thousands of dollars per year, per truck.”
Darwyn Jones, transportation manager for Wal-Mart, agrees. In a recent statement made at an industry conference, he said that his company had installed auxiliary power units (APUs) on its 6,845 tractors and saved $22 million in 16 months, which was the result of saving 10 million gallons of fuel.
Engine idling has become a habit for some drivers, Saxman says. P&D applications or other vehicles that do not have sleeper cabs, have drivers that idle during routine daily deliveries because they are used to doing so.
“While idling for hotel loads may be valid, there are now viable options,” he says. “We have oil fed cab heaters that use diesel fuel and keep drivers warm when the vehicle engine is turned off. For summer heat, the industry is still working on cooling alternatives.”
According to Cyndi Nigh, manager – on-highway communications for Cummins Engine Co., limiting engine idling will reduce fuel costs, help fleets comply with anti-idling legislation, reduce noise and emissions and also reduce the wear and tear on the main engine.
“Idle time can significantly affect the vehicle’s fuel efficiency,” she says. “The vehicle gets its worst mpg when the engine runs and the truck doesn’t move. Every hour of idle time in a long-haul operation can decrease fuel efficiency by 1 percent. Trucks that idle a significant percentage of the time can have increased fuel costs of up to several thousands of dollars a year.”
Jerry Warmkessel, marketing product manager for highway products at Mack Trucks, says engine idling, if done at 1,000 RPMs or less, does not have the negative impact on engines as idling did in the past. A few years back, engines used to “slobber,” he says, but the new designs and lubricants are much more efficient. Even though some of the engine wear concerns are no longer an issue, Warmkessel says that excessive idling still needs to be curbed. Now, however, the concern is for complying with laws governing emissions.
Idling alternatives
APUs can be described as portable, truck-mounted systems that can provide climate control and power for trucks without idling. Typically, but not exclusively, the systems consist of a small internal combustion engine (usually diesel) equipped with a generator and heat recovery system to provide electricity and heat. For air conditioning, an electrically powered air-conditioner unit is normally installed in the sleeper, although some systems use the truck’s air-conditioning system.
A basic APU is a direct-fired heater, but it cannot provide air conditioning or power for other applications such as a television or microwave. For those amenities, a more sophisticated APU is needed, one that has a generator powered by a diesel engine, a compressor, an alternator and an inverter/charger.
There are lots of APU options to idling engines these days. Many of the OEMs and engine suppliers have partnered with genset and APU providers to offer spec’ able alternatives.
Freightliner Trucks North America offers Bergstrom’s idling-reduction technology as a factory-installed option on the Century, Coronado and Columbia Class 8 truck models. The Bergstrom NITE (no-idle thermal environment) system consists of a rechargeable battery system that supplies electricity to a sealed air-conditioning unit and an auxiliary heater. The system works independently of the vehicle’s main engine.
Nigh says that her company offers the Cummins ComfortGuard APU System, which is an integrated vehicle mounted small diesel APU system that eliminates the need to idle the main vehicle engine, significantly reducing fuel costs, emissions and noise. The system features a genset by Cummins Onan, a Cummins brand and provider of mobile power generation.
“The system is equipped with a powerful heating and air-conditioning system that keeps the driver comfortable when the main truck engine is off. It provides both 120-volt AC and 12-volt DC electrical power to quietly operate the truck’s cab and hotel loads including air conditioning, cab heating, computer, TV/DVD/VCR, microwave, coffee maker, battery charging, fans, lights and more,” Nigh says.
The system provides both manual and automatic operation to manage APU use for fuel efficiency, comfort and convenience. In addition to the APU, Cummins ComfortGuard APU System includes the evaporator, condenser and thermostat. The system is powerful enough to heat and cool the truck’s cab with ease. The system is designed for easy installation on trucks at authorized Cummins locations. Payback varies but is usually less than two years, Nigh says.
Mack Trucks has been researching alternative APU technologies. A new system the company is testing will help Mack customers limit engine idling, Warmkessel says. The truck maker has been working with Idle Free Systems, which provides an electrically powered alternative system. Mack is testing it in a daycab configuration, but the technology is capable of providing the power to heat and cool a sleeper cab. “What we have installed, is a total key-off HVAC solution,” says Warmkessel.
Robert Jordan, the president of Idle Free Systems, says the system works much like hybrid technology in that 12-volt energy is created while driving and stored in applied glass mat (AGM) batteries located on the vehicle. In the case of the system used on the Mack truck, there are three AGM batteries in the bunk area and two in the battery box adjacent to the regular starter batteries, because that is what Mack requested for its system. This is a variation of Idle Free System’s Reefer Link System, a system that uses two or three AGM batteries. The Mack installation is unique because it has both the Idle Free Hybrid System as well as the Idle Free Reefer Link System.
The system draws power from three sources, the parent diesel engine, a reefer engine or a shore power connection, he says. The non- reefer truck would use the hybrid system (5 AGM batteries) while the Reefer Fleet would use the Reefer Link System (2 or 3 AGM batteries). Both systems would deliver up to 10 hours of key-off power when the driver is resting.
Both Warmkessel and Jordan point out that there have been emission concerns surrounding diesel powered APUs, and that legislation is pending in California related to regulating APUs. At this point, California is the only state expressing concerns over the idling of diesel powered APUs. At the basis of that concern is that current APU diesel engines are not subject to the same EPA (NOx and particulate level) standards as those imposed on ’07 diesel engines. A related issue is that while ultra low sulfur diesel fuel (ULSD) is mandated for truck diesel engines, some users of APUs may be unaware that they are required to use ULSD as well.
APU aftermarket options
There are a number of APU aftermarket choices. Thermo King offers TriPac auxiliary heating/cooling temperature management system that uses a fuel-fired heater and Thermo King’s Cycle Sentry start/stop technology to achieve fuel efficiency, the company said. A two-cylinder diesel engine powers an air-conditioning compressor and a 12-volt alternator, both of which are belt driven. These components power the air-conditioning system, keep the truck batteries charged and provide tractor engine heat.
In cool climates, the TriPac engine will only operate if battery charging or engine block heating is required. If not, only the fuel-fired heater will operate to warm the cab while consuming minimal fuel, the company said. TriPac offers 1,000-hour maintenance intervals, designed to allow maintenance to be performed at the same time as maintenance on the tractor.
Carrier Transicold said it is the exclusive worldwide distributor of Teleflex Inc.’s APU products, which were renamed the ComfortPro series. The APU does not draw power from the truck’s battery. Instead, it powers its cooling and heating system and all onboard appliances through a 4,000-watt generator, which is driven by the unit’s Kubota diesel engine. The unit provides air conditioning and heating for sleeper cabs; 110/120-volt AC household current; 40 amps of truck-battery charging with battery-charge monitoring; truck engine warming; Winterwatch protection to keep the engine warm when the cabin is not occupied; start/stop operation; and an optional ability to tap into shorepower.
Carrier recently announced that its ComfortPro Auxiliary Power Unit has been improved with a 1,000-hour service interval, industry-standard R134a refrigerant and a 60-amp alternator. These are among multiple performance-boosting enhancements that also lower life cycle costs according to Carrier, a business unit of United Technologies Corp. The APU is an anti-idling solution for the trucking industry providing air conditioning, heating and household electrical current for a truck sleeper cab, battery charging and truck engine warming. The company said it is unique among the growing field of APUs as it offers an all-electric architecture – the award-winning Deltek hybrid diesel-electric technology found in Carrier’s Vector 1800MT trailer refrigeration units.
Webasto combined its Air Top 2000 forced-air heater with its BlueCool Truck air conditioner into the C5 system, which allows truckers to cool and heat their truck sleeper bunks without depending on power from an idling diesel engine. Technically, this is not an APU, but it functions as one. Its cooling component uses small amounts of electricity to circulate super-chilled coolant (between the cold storage unit and a heat exchanger in the truck sleeper cabin) and run four small, quiet air distribution fans. Webasto says that the controls are simple: one rotary temperature knob and an infinitely variable fan speed control with an integrated on/off switch. Air vents are manually adjustable to provide optimal airflow throughout the cabin. The unit’s forced-air heater uses diesel fuel from a vehicle’s tank to warm the interior. It consumes 0.05 gallon of fuel per hour, the company said.
The cooling component is frozen during the day while the truck is running. At night, it provides a source of cold, dehumidified air to the bunk area with no further use of a powered air-conditioning device, the company said. With an output of 7,000 BTU/hour, the heater provides instant, quiet and safe overnight heat, according to the company. It can be operated via an optional timer or manually controlled.
“Auxiliary power units (APUs) and small generators (gensets) offer alternatives to truck idling,” says Eldon Willis, vice president and chief technologist for Willis APU. “They can save operators thousands of dollars in fuel costs and avoided fines for violations of anti-idling regulations.”
An APU or genset generally burns between a pint to a quart of fuel per hour, Willis says. That’s considerably less than the gallon per hour a Class 8 truck engine typically guzzles while idling. So, paybacks can range from 10 to 24 months, depending on the cost of fuel and the percentage of time the operator’s truck spends at idle. Willis says.
With so many choices, Willis suggests operators carefully consider their needs, whether a genset or an APU will meet them, and which brand and model provide the best value. While the terms are often used interchangeably, there are important differences between APUs and gensets.
According to Willis, gensets typically generate power to operate heating and cooling devices and amenities like refrigerators and personal appliances, but they don’t provide direct heating or cooling to the cab and sleeper. Generally, APUs offer HVAC comfort as well as power through an internal combustion engine, air conditioning compressor and alternator.
Will Watson, vice president of sales and marketing for Auxiliary Power Dynamics, manufacturers of the Willis Auxiliary Power Unit, said its APU offers a unit that uses a three-cylinder, 18-HP Kubota engine, which is quiet, powerful and inexpensive to maintain. By addressing driver comfort, fleets stand a better chance at keeping their good drivers or recruiting and retaining the best candidates.
Will Watson says financing options are available, including a lease option that allows well-qualified fleets to get the Willis APU installed for little or no money down.
“Depending upon how much idling your drivers currently do, the amount of money your company will save in fuel costs may actually be more than your monthly lease payment,” he says.
Compendium of Idling Regulations
Idling Control System Resources
Auxiliary Power Dynamics, LLC: Willis – APU, 800-825-4631, www.willisapu.com
Bergstrom: NITE system – Battery powered independent heating/air conditioning system, 866-204-8570, www.nitesystem.com
Black Rock: APU, generator component – 2-cylinder balances between HVAC and power generation 775-246-5791, www.blackrockapu.com
Carrier Transicold: ComfortPro – APU, compatible with shorepower, generator as well 706-546-6469, www.trucktrailer.carrier.com
Cummins: ComfortGuard – OEM genset, 800-DIESELS (343-7357), www.cummins.com
Dometic Tundra: Idle Solutions – APU Auxiliary air-conditioning system, 800-275-0574, www.idlesolutions.com
EcoWind Power: APU, 866-591-WIND (9463) www.ecowind-power.com
Espar: Total Comfort System – Independent heating/air conditioning system, 800-387-4800, www.espar.com
Executive Technologies: Executive Air System – APU and generator 888-710-8907, www.etairsystem.com
Idlebuster: Genset with inverter and shorepower, 727-569-6000, www.fcma.com
Kohler: APU and generator, 800-544-2444, www.kohler.com
Lease Corp. of America: Idle reduction equipment leases. 800-800-8098, www.leasecorp.com
Mechron: APU and generator, 613-733-3855, www.mechron.com
Phillips and Temro: Cab power shorepower systems – battery inverter kit, 952-941-9700, www.phillipsandtemro.com
Pony Pack: APU, 505-243-1381, www.ponypack.com
Power Tech Generators: Power Pac, TPU-7000 – APU and generator 800-760-0027, www.powertech-gen.com
SCS/Frigette: Gen set and APU hybrid, 800-433-1740 or 800-433-2910, www.scsfrigette.com
Rig Master: APU and genset, 800-249-6222, rigmasterpower.com
Thermo King: TriPac – APU hybrid, 952-887-2200, www.thermoking.com
Webasto: BlueCool Truck – Electric air handler cold storage cell and circulating fan/dehumidifier, 810-593-6000, www.webasto-us.com
Xantrex: Portable and backup power, 604-422-8595, www.xantrex.com
