Peterbilt's ComfortClass system will be available in 63-inch sleeper configurations beginning in June 2008,
the company announced at the 2008 Mid-America Trucking Show. The system is currently available in Peterbilt Class 8 vehicles equipped with a 70-inch Unibilt sleeper.

The Peterbilt ComfortClass system, a combination of batteries and a thermal storage cooler, provides a temperature-controlled environment and the capacity to run computers, microwave ovens and other electronic devices in the sleeper. The system provides heating, cooling and 110-volt electrical power without the need for the engine to run for up to 10 hours.

While the vehicle is in operation, a 185-amp alternator charges the power pack (four dedicated, advanced glass mat, deep-cycle batteries) and starting batteries. At the same time, the electric air conditioning compressor charges the thermal storage unit mounted behind the sleeper. The ComfortClass system can reduce annual fuel consumption by approximately 8 percent.

When the ComfortClass system is activated, the power pack batteries supply power to an electric fan blower under the sleeper bunk as well as a circulating pump for cooling fluid that circulates chilled fluid through the thermal storage unit and into the sleeper. Air temperature is regulated by adjusting a thermostat and fan speed dial conveniently located in the sleeper area, near the bunk.

In cold climates, the ComfortClass system uses a small diesel-fired heating unit which is mounted under the bunk. Also thermostatically controlled, with ducting below the bunk, the unit keeps the sleeper and cab warm in temperatures below freezing. If shore power is available, the system can be plugged in to provide power for all the system functions, as well as hotel loads and battery charging needs.