A graphic of a Class 8 truck with cabin climate-control technologies pointed out.

NREL’s Class 8 truck climate-control package showcased in Automotive Engineering; saves fuel and maintains driver comfort.

When you spend your days on the road as a truck driver, it’s understandable that having a comfortable and convenient sleeper compartment ranks as a high priority. Yet when many long-haul trucks are parked and idling for extensive periods of time, it becomes a challenge to maintain driver comfort and minimize fuel use. In fact, long-haul Class 8 trucks use approximately 7% of their fuel for rest period idling, consuming more than 667 million gallons of fuel each year nationwide.

Enter the Complete-Cab Truck Climate Control Package—an integrated suite of climate control reduction technologies developed by researchers at the National Renewable Energy Laboratory (NREL). The innovative package, which was recently featured in an Automotive Engineering article, includes a combination of Thinsulate insulation, ultra-white paint, and advanced window shades designed to complement a battery-powered auxiliary heating, ventilation, and air conditioning (HVAC) unit. The combined system can save 774 gallons of fuel annually per truck. Depending on the drive cycle and idling time, it has the potential for full payback in about three years.

“The project goal was to reduce cab thermal loads to enable smaller, lighter, and more cost-effective idle-off climate control equipment,” explained NREL Researcher Jason Lustbader, who heads up the lab’s heavy-duty vehicle thermal management research.

These combined thermal solutions reduced the air conditioning load by 35.7% and the heating load by 43%, with an even more impressive 53% reduction in heat-transfer coefficient when another layer of advanced insulation was added. Modeling with NREL’s CoolCalc load-estimating software showed major reductions in battery capacity requirements and improvement in air conditioning performance.

“Combining thermal load reduction technologies with battery electric air conditioning can improve system payback period and performance, providing fleet owners with additional economic motivation to adopt the technology,” Lustbader said.

For more information, see the full Transportation and Hydrogen News article or NREL’s recent report on long-haul truck sleeper heating load reduction.