Alliance Parts, the private-label brand of Freightliner LLC, has introduced the 2007 Alliance Premium Auxiliary Power Unit (APU). It provides 12,000 BTUs of air conditioning, 10,000 BTUs of heating and 3300 watts of 110-volt electricity. Its one-cylinder engine, claimed to be unique in the industry, burns just one-tenth of a gallon of fuel an hour.

The APU, manufactured by SCS Frigette in Dallas, Tex., is a
free-standing unit operating independently of the truck’s factory HVAC system. It integrates with the truck only through a supply and return line to the fuel tank, so it doesn’t violate any OEM warranties.

Standard features include custom duct work with six directional louvers to ensure that cold air is well distributed throughout the sleeper – including the top bunk. The unit has six 110-volt outlets for microwaves and such, and a 60-amp charger maintains the truck’s batteries when the APU is running. A simple control panel is mounted near the bunk.

Engineering enhancements have resulted in significant noise reduction, says Alliance. A new air intake and filter design, custom engineered muffler, as well as additional
insulation material are said to make the Alliance APU one of the quietest on the market – it generates only 73 to 77 decibels of noise.

It’s not aimed solely at Freightliner trucks, incidentally, but can be bought and installed on any other make. Still, custom-engineered versions are offered for the Freightliner
Coronado, Columbia and Century Class. Its attractive-plate step-box design can be placed behind the fuel tank, and it weighs a relatively light 418 lb. The unit includes a
limited warranty of two years or 4000 hours, whichever comes first. The first oil and filter change interval is 50 hours, after which the interval is 500 hours, which normally will coincide with the truck’s PM schedule.

Alliance notes that the belt-alignment issue experienced in earlier versions of the APU have been resolved. Units produced since June 2006 are equipped with a special
one-piece bracket that eliminates such problems.