Thermo King Unveils New Bus HVAC Heat Pump with Natural Refrigerant

Thermo King unveiled  the new Athenia MkII heat pump with R-744, an environmentally friendly, natural refrigerant. The new heating, ventilation and air conditioning (HVAC) technology for buses, presented today at the IAA Transportation 2022 show in Hannover, Germany, has been designed specifically for electric and hybrid buses and optimized to deliver passenger comfort and sustainable operation with market leading performance.

The R-744, often named CO2, is a natural, non-toxic, non-flammable and non-ozone-depleting refrigerant with global warming potential (GWP) of just 1. Thanks to its capabilities, the new Athenia MkII R-744 heat pump has been optimized to offer maximum passenger comfort not only during the summer months when cooling is required, but also during the coldest winters – with no need for additional heaters or boilers. The unit is capable of operating in heating mode in ambient temperatures as low as -25°C and deliver cooling when the temperature is as high as +50°C.

The new Athenia MkII R-744 heat pump is an “all-in-one” rooftop unit optimized to keep the driver and passengers at the right comfort level with heating, cooling and fresh-air control. Simultaneously the unit protects the bus driveline batteries by providing cooled or warmer water to condition them during charging and discharging. The integrated Battery Thermal Management System optimizes overall energy use, ensuring high coefficient of performance (COP) levels of the system and reducing lifecycle costs. The “all-in-one” unit can also utilize waste heat from other sources in the vehicle to further optimize energy usage and contribute to passenger comfort.