Thermal Management Innovations
In recent years, various thermal management innovations have occurred, including advanced cabin climate controls and phase-change material technologies.
Advanced cabin-climate systems allow drivers to stay cool or warm during a complete rest break with the engine off by combining high-density lithium-ion eAPUs, variable-speed refrigerant compressors, and reversible heat-pump cycles with smarter load-management software and optional thermal-storage components. Battery packs of 6 to 8 kWh in units can power 7,500 to 9,000 Btu/hr. of HVAC for 10 to 15 hours, while predictive controls adjust fan speeds, close dampers, and pre-chill or pre-heat the cab based on occupancy sensors and state-of-charge.
Phase-change material (PCM) systems provide zero-emission cooling for cabs and cargo by freezing during driving or shore power connection and melting during rest periods to release stored thermal energy. Common in medium-duty refrigerated trucks, they add some weight compared to other idle-reduction systems. They then release latent “cold energy” during rest stops, allowing HVAC compressor operation without idling.
