Light-Duty Vehicle Thermal Management

NREL researchers are working to improve the thermal efficiency of light-duty vehicles (LDVs) while maintaining the thermal comfort that drivers expect.

NREL evaluates the effectiveness of thermal management strategies including:

• Thermal load reduction, using technologies and methods such as advanced window glazing, heat-pipe cooling systems, parked-car ventilation, and insulation
• Occupant thermal comfort optimization, using technologies and methods such as zonal climate control and heated, cooled, and ventilated seats
• Intelligent heating, ventilating, and air conditioning (HVAC) controls that automatically adjust to conditions to provide optimum fuel efficiency and comfort
• Thermal preconditioning to achieve comfortable cabin temperatures and preheating or precooling the battery while the vehicle is still plugged in.

Researchers use a wide range of NREL tools to evaluate LDVs. Thermal manikins add another dimension to these evaluations, allowing researchers to gauge the impact of technology solutions on driver and passenger thermal comfort. Analogous to crash-test dummies, these manikins measure heat loss and skin temperature through numerous sensors, making it possible to efficiently and accurately predict responses to climate control adjustments.

The power required to cool passenger compartments also lowers the fuel economy of conventional LDVs with gasoline engines. About 5.5% of total national LDV fuel use can be attributed to cooling systems. Improvements to climate control systems can make petroleum-powered vehicles more fuel efficient. NREL researchers have examined the potential of improved cabin insulation, advanced window systems, advanced cooling and venting systems, and waste heat utilization.

Models and Tools

CoolSim: Heating, Ventilation, and Air Conditioning Model

VSOLE: Vehicle Solar Load Estimator

Publications

A Framework for Characterizing the Ambient Conditions Experienced by Light-Duty Vehicles in the United States, International Journal of Sustainable Transportation (2021)

A Framework for Characterizing the Initial Thermal Conditions of Light-Duty Vehicles in Response to Representative Utilization Patterns, Ambient Conditions, and Vehicle Technologies, SAE International Journal of Passenger Cars – Mechanical Systems (2021)

Contact

To learn more about our LDV thermal management research or explore partnership opportunities, please reach out.