APU Semi Trucks

APU Semi Trucks

Auxiliary Power Unit for Semi Trucks,

In the United States, Federal D.O.T. regulations require a 10 hour break for every 11 hours of driving time. When resting drivers often idle their trucks for heat, light and power for A/C which burns fuel and puts wear and tear on an engine. Some trucks carry an APU made to do away with these long idles. An APU can save up to 20 gallons of fuel per day, and can prolong the life of the trucks engine by 100,000 miles. It is now Illegal in many places in the USA to idle a truck because of noise regulations. An APU is becoming a must have in the Trucking Industry now because of these reasons. The most common APU for a Big truck is a small diesel engine with its own cooling system, heating system, generator or alternator system with or without an inverter, and a/c compressor, housed in an enclosure and mounted to the frame rail of a big truck. Some models fully integrate the auxiliary cooling, heating, and electrical components throughout the chassis of the truck. The APU generator engine is just a fraction of the main engine's size and uses much less diesel, some units can run for 8 hours on 1 gallon of fuel. The generator also powers the main engine block and fuel system heaters, so the main engine can be easily started right before departure if the APU is allowed to run for a while before starting. These units are used to provide climate control and electrical power for the truck's sleeper cab and engine block heater during downtime on the road.

Electric APUs have started to gain some acceptance. The electric APUs have battery packs instead of an engine on traditional APUs as a power source. The battery pack is charged when the truck is in motion. When the rig is idle, the energy stored in the battery pack is used to power an a/c, heater, and whatever devices are in the sleeper berth.

Lately, truck and fuel cell manufacturers have joined together to build, test and demonstrate a fuel cell APU that eliminates nearly all emissions and uses fuel more efficiently. About 4 years ago a DOE sponsored partnership between Peterbilt Delphi Electronics proved that a fuel cell could provide power to the electronics and a/c of a Peterbilt truck under simulated idling conditions for 10 hours. Delphi has said the 5 kw system for Class 8 trucks will be released this year (2012), at about $8,000 to $9,000 that would be competitive with other medium two-cylinder APUs, if they can meet those deadlines and cost estimates.