Mobile citybus air-conditioning

Mobile open and Semi-hermetic Compressors

for bus, train air conditioning and transport cooling

The criteria for air conditioning in buses and trains are fundamentally very high and must be strictly observed in the development of ventilation systems. Due to the advancing climate change, electromobility and efficient energy consumption are becoming more and more in focus. A very important point in the air conditioning of buses, trains or in transport cooling is the weight of the cooling application. Here, value is placed on robust lightweights in order not to unnecessarily burden the permissible total weight of a loaded bus. Thanks to decades of development, innovation and engineering experience, the mobile BOCK compressors make their contribution to the environment and ensure a good climate in buses, trains and all transport refrigeration applications.

Open compressors


BOCK open type vehicle compressors FK40 for mobile applications

BOCK vehicle compressors of the FK series are the result of decades of experience in the field of mobile refrigeration. The Bock compressor FK40 has now been on the market for more than 50 years and is the worldwide standard of the most renowned manufacturers in the field of bus air conditioning.

Product benefits :

  • Lightweight, compact, robust, wide speed range
  • Demand-oriented capacity regulation possible
  • Unique valve plate option
  • Product range with 2-, 4- and 6-cylinder reciprocating compressors
  • For individual cooling applications in a wide range of design variants possible


FK - compressors

semi-hermetic compressors


Semi-hermetic compressors

The HGX34 and HGX22 compressors - developed on the basis of the BOCK gas-cooled semi-hermetic compressor series - have been specially designed for mobile applications in bus and rail air conditioning.

Thanks to the lightweight aluminum construction, the mobile semi-hermetic compressors are the perfect solution for applications where weight is important. Compared to the standard compressor 40% lighter compressors therefore offer system manufacturers better options.

BOCK mobile compressors are available in 2 and 4 pole versions. In the 2-pole version, the speed is doubled compared to the 4-pole versions and the cooling capacity is significantly increased for the same size. The 2-pole compressor HG34 is available in cast iron as well as in aluminum.


CO2 solutions for mobile applications

HR40 and HGX24 Co2 LT

HR Compressor
BOCK transcritical CO2 compressor HGX24 CO2 T

Bock StarCO2mpressor HR 40 - naturally innovative!
The innovative "star" engine design of the StarCO2mpressor opens up new possibilities in electric bus and rail air conditioning: space-saving roof installation thanks to the industry's lowest overall height and lightest weight. And energy-saving heat generation without auxiliary heater even at outside temperatures down to -20 °C.


The new CO2 compressor series HGX24 CO2 LT for deep-freezing with high standstill pressures 
High pressures are generally not a special feature in CO2 applications.
However, for an optimum design, the requirements of operating and
of the operating pressure and the upcoming standstill pressure must always be considered. The proven subcritical CO2 compressors from BOCK enable
standstill pressures of up to 40 or 30 bar...