The Hitchhiker auxiliary power unit and HVAC system is a new entrant on the scene from Idle-Kleen Inc. in Cambridge, Ont. It provides ndependent all-electric heating and air-conditioning to reduce unnecessary engine idling, but its real claim to fame may be its light weight and compact size. At just 220 lb or about 100 kg as it sits on the frame rail, it’s half the weight of some others.

And the company says it can be installed in only 4-6 hours in your own driveway with no special tools. All components are pre-assembled for plug-and-play installation, and you don’t have to install AC lines or fittings as the unit comes pre-charged and sealed from the factory. The only truck system you have to connect to the unit is the fuel tank, using supplied fuel lines and fittings. There’s no frame drilling to do either; instead, you get custom designed frame grippers to mount the generator to the side of the frame rail, which is said to take about 10 minutes.

The system runs on 115-volt AC power, which is supplied by the Hitchhiker unit or a shore-power connection. Models are available in 10,000 and 14,000 BTU/hr sizes, with 1.5, 2.0 or 2.5 kW of electric heating capacity (other heating capacities are available on special request). At the core of things is a single-cylinder, air-cooled diesel engine.

The HVAC system consists of a separate evaporator inside and a condenser mounted outside, connected by flexible refrigerant lines. They’re designed specifically for the harsh trucking environment. Made by Dometic and said to be vibration- and corrosion-resistant, they’re backed by more than 40 years of mobile air-conditioning experience. A digital thermostat controls the system and is ordered separately. Environmentally riendly R-417A refrigerant (HFC) is used.

Idle-Kleen says the Hitchhiker will supply ample power for all electrical needs while drawing nothing from the truck’s batteries. Two duplex receptacles mounted in the cab supply 110-volt AC household power to run appliances such as computers, coffee makers, and microwaves. Continuous trickle charging of the truck’s batteries helps to ensure a positive engine start while extending battery life too.

Maintenance promises to be simple because there are no belts, pulleys, or water pumps to maintain or break down. It uses a direct-mount, crankshaft-driven alternator. The only maintenance needed is an oil change every 500 hours.

Prototypes of the Hitchhiker have been in tests since February of 2005, including 140 units at Challenger Motor Freight, also in Cambridge. Idle-Kleen says tests have shown the APU can operate equally well in minus-22-degree weather or 110-degree heat. The company also says that
annual fuel and maintenance savings of $6300 or more are feasible, and since the APU costs under $7000, payback is possible in less than 12 months.