Thermo King’s TriPac APU

Thermo King recently introduced the TriPac auxiliary heating/cooling
temperature-management system, originally designed by a TK dealer. An APU
makes more and more sense as fuel prices rise, as it eliminates unnecessary
idling.

The TriPac provides sleeper-cab heating and air conditioning, battery charging, accessory power, and engine-block heating. A Thermo King (Yanmar)
two-cylinder diesel engine powers an air-conditioning compressor and a 12-volt
alternator, both of which are the belt-driven ‘automotive’ style. These components
power the air-conditioning system, keep the truck batteries charged, and provide engine heat. The engine block is heated by incorporating the engine coolant systems between TriPac and the truck engine. The engines warm each other
while running, and the system incorporates engine-coolant temperature sensing via an ‘arctic’ option. Cab heating is provided via a fuel-fired Espar heater.

The system delivers 12-volt DC accessory power to the cab. If you want 120-volt
AC power, an optional power inverter can be provided. All these components are
incorporated via a programmable microprocessor with a backlit control panel in the sleeper compartment. The programmable features allow the dealer to set
control parameters and optimize the TriPac system, such as adjusting the limits
for battery charging.

Its modular design means the TriPac can be installed in a variety of truck models and configurations. The engine assembly or APU is mounted on the truck frame rails, with the air-conditioning evaporator and fuel-fired heater installed under the
sleeper bunk, and the condenser is installed on the rear cab wall. Ducting is
flexible and can be routed directly to the cab or integrated with existing ducting.

TriPac is differentiated, says Thermo King, by the unique use of a fuel-fired heater and start/stop technology to achieve maximum fuel efficiency. 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. When battery charging and block heat are necessary, the
TriPac can start automatically and then shut down to save fuel. The result is said to be a system that runs substantially fewer engine hours than competitive models.

The full system weighs 425 lb and costs in the range of C$11,145 installed,
including an 1800-watt inverter and Arctic Pack charging management system,
according to Mid-Canada Thermo King in Winnipeg.