Mack Markets In-Cab System to Reduce Engine Idling

By Frederick Kiel, Staff Reporter

This story appears in the June 4 print edition of Transport Topics. Click here to subscribe today.

Mack Trucks introduced a new in-cabin power system as an option, joining several other truck manufacturers — including International, Kenworth and Peterbilt — in offering built-in units to limit idling.

Mack said its system allows drivers to heat and cool their cabs and run electrical appliances including refrigerators, TVs and computers for up to 10 hours without idling the engine or working off the typical auxiliary power unit.



“The smart operator wants to avoid idling these days,” Jerry Warmkessel, Mack’s marketing product manager of highway products, said in a statement.

“The price of fuel is near record levels, many local and state environmental regulations strictly limit the amount of time trucks may idle, and fleets now recognize the increased maintenance costs of excessive idling,” he said.

The Mack system, known as the Idle Free Hybrid System, uses a bank of what the company said are high-efficiency absorbed glass mat batteries to provide stored electrical power for heating, air conditioning and amenities, such as a television or microwave. The sealed AGM batteries can be safely housed inside the truck and are stored under the sleeper’s bunk, Mack said.

The batteries can be re-charged three different ways: by the truck’s alternator when the engine is running; through a shore power connection when the vehicle is stopped; or through an available con-

nection to the reefer unit for tractors hauling refrigerated trailers.

When the truck is not moving, the driver can use battery power or shore power to run heating, air conditioning and amenities. The system provides either 12- or 120-volt power.

Jeff Paretti, a spokesman for Kenworth Truck Co., told Transport Topics that Kenworth introduced a similar system last year, and it will be available as an option beginning this month. Peterbilt Motor Co. offers the same system, calling it, “ComfortClass.”

“The ComfortClass system can reduce annual fuel consumption by about 8%,” Peterbilt Chief Engineer Landon Sproull said in a statement last year. “That results in a significant bottom-line improvement by reducing operating expenses by as much as $5,000 a year, per vehicle.”

The systems for Mack and Peterbilt also will be available in June.

“The Kenworth Clean Power no-idle system has the capability to provide engine-off cooling and heating, and 110-volt ‘hotel load’ power,” a Kenworth statement said.

“Kenworth’s new energy-efficient LED [light emitting diode] lighting and sleeper insulation package will keep the sleeper even more comfortable by helping to minimize air conditioning and heat loss.”

Kenworth Clean Power uses dedicated, advanced glass mat, deep-cycle batteries that power a Thermal Storage Cooler. The Storage Cooler, about the size of a microwave, fits under the bunk.

As the Kenworth truck is driven down the road, or if the truck is connected to a 120-volt AC electrical supply, the liquid inside the Storage Cooler is cooled to freezing, which translates to about 21,000 British Thermal Units of cooling capacity.

When the truck is shut off, the battery-powered cooling system, turned on from the sleeper control panel, takes over and keeps the sleeper at temperature, Kenworth said. A thermostat regulates the desired temperature and a variable speed fan circulates chilled air through a duct located near the bunk.

Mack, Kenworth and Peterbilt said their systems will keep the cabs comfortable for 10 hours in 90-degree heat. All three systems include a small diesel-fired heater mounted under the bunk, controlled with a thermostat.

Mack said that the U.S. Environmental Protection Agency estimates heavy-duty truck idling in the U.S. consumes 960 million gallons of diesel fuel annually. According to EPA, truck idling results in annual emissions of 11 million short tons of CO2, 180,000 short tons of NOx and 5,000 short tons of particulate matter.

International Truck and Engine Corp. introduced its own factory-installed “No-Idle Solution” in March 2006, for production in 2007.

“The International No-Idle APU allows drivers to operate heating or air conditioning, as well as ‘hotel loads,’ such as a microwave or television, without running the engine of the truck,” International said in a statement last year.

“It offers [6-kilowatt], 120-volt AC power, plus 50-amp, 12-volt battery charging; and provides 10,000 BTUs an hour of air conditioning or heat.”

A spokesman for Volvo Trucks North America said the company did not offer any battery system similar to those of Mack, Kenworth and Peterbilt.

Freightliner LLC did not respond to requests for comment.