The DB2 CTMS provides a fully integrated thermal management architecture tailored to the demands of double-deck electric buses. A twin-circuit reversible heat pump delivers efficient upper saloon air conditioning and upper/lower saloon heating, while battery active cooling, passive cooling, and heating functions, and power electronics and traction motor cooling, maintain powertrain system temperatures within optimal operating limits.

Twin electric scroll compressors, integrated water tanks and a CAN-controlled architecture enable precise temperature regulation through Grayson’s Intelligent Thermal Controller and proprietary software. With waste-heat recovery and high-voltage capability up to 900V DC, the DB2 improves efficiency and supports the stringent demands of modern electric double-deck fleets.

Designed for rear-integration and easy service access, the DB2 CTMS is the proven, all-in-one thermal solution for OEMs developing the next-generation of zero-emission double deck buses.

These features work together to support efficient operation, consistent performance, and overall product effectiveness.

• Complete Multi-Zone HVAC: Upper-deck blown-air heating and air conditioning using a reversible heat pump / Lower-deck water-glycol heating loop.
• Battery Thermal Management Functions: Direct coolant-loop interfaces for active cooling, passive cooling and battery heating.
• Integrated Power Electronics Cooling: Power electronics and electric traction motor cooling built into the system.
• Twin Scroll Compressors and Low-GWP Refrigerant: Delivers high heating and cooling efficiency with reduced electrical consumption.
• Waste-Heat Recovery as Standard: Improves energy efficiency and supports extended vehicle range
• Grayson Intelligent Thermal Controller: Developed and validated by Grayson for precision regulation.
• CAN J1939 Communication: Compatible with pumps, valves, water heaters and additional HVAC components.
• Dynamic Control Software: Continuously adjusts operation to match vehicle thermal demands.
• High-Voltage Compatibility: Up to 900V DC, meeting the needs of next-generation electric platforms.
• Service-Access Friendly Design: Minimises downtime and supports fast maintenance turnaround.
• Integrated Water Tanks: For battery and lower deck heating loops
• Compressors: Twin electric scroll compressors

These technical capabilities define how the product is built and how it performs as a complete system.

• Dimensions (L × W × H): 766 × 2002 × 909 mm
• Weight: 245 kg
• Refrigerant: R407C
• Operating Temperature: -15°C to +35°C
• Upper Deck HVAC Cooling: 16 kW at 35°C ambient, 27°C interior
• Upper Deck HVAC Heating: 18 kW at 0°C ambient, 17°C interior
• Lower Deck HVAC Heating: 14 kW at 0°C ambient, 17°C interior
• Battery Active Cooling: up to 14 kW at 15°C ambient, 20°C coolant, 45 l/min
• Battery Passive Cooling: up to 5 kW at 15°C ambient, 25°C coolant, 45 l/min
• Battery Heating: 3.6 kW @ 600 V DC (with 100 Ω load)
• High-Voltage Range: 420–900 V DC
• Low-Voltage Supply: 24 V DC
• Refrigerant: R407C
• Compressors: Twin electric scroll compressors
• Communication: CAN J1939
  
  *Model dependent

• 3E-10001-0J01 – 600V DC: Passenger Heating, Air Conditioning and BTMS
• 3E-10001-0H01 – 600V DC: Passenger Heating and BTMS

*Contact Grayson today to learn more about 900V DC options