Semi-hermetic compressors: HG and HA-series

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  • Related applications
  • Case studies
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BOCK® HG & HA compressors: Cooling efficiency and reliability revolutionized

Danfoss BOCK®'s HG range offers traditional suction-gas-cooled compressor technology, excelling in ease of operation, low maintenance, high efficiency, and reliability. On the other hand, the air-cooled HA range is specially engineered for low-temperature applications, preventing overheating by air-cooling the motor and cylinder heads separately from the suction gas.

These ranges are available in a variety of low-GWP refrigerants as well as traditional HFCs. Experience a cooling revolution with BOCK compressors, delivering unmatched performance and temperature control.

Features and benefits of HG and HA compressors:

Improved efficiency: enhanced performance and greater displacement stages lead to increased efficiency

Compact design: the compressors feature a more compact structural design for easier integration

Energy savings: advanced valve plate system, latest-generation electrical motors, and improved gas flow reduce energy consumption

Compatibility: redesigned connections align with industry standards, ensuring seamless replacement without adaptation work

Versatility: suitable for various applications, including refrigeration, air conditioning, and supermarket refrigeration

  • 7 model sizes with 25 capacity stages from 5.4 to 281.3 m³/h (50 Hz)
  • Refrigerants: R448/9A, R513A, R450A, R134a, R407A/C/F, R404A
  • Proven and reliable oil pump lubrication
  • Standard footprints
  • Standard-position sight glass
    mexxFlow® 2.0 valve plate system
  • Newly designed housing with optimized gas flow
  • Standard-position valves
  • Highly efficient electric motors of the latest generation
  • Exchangeable motor
  • Electric motor protection
  • 3 model sizes with 10 capacity stages from 11.1 to 57.7 m³/h (50 Hz)
  • Refrigerants: R448/9A, R407A/F, R404A
  • Proven, reliable oil pump lubrication system
  • Standard mounting position
  • Standard position sight glass
  • New designed housing with optimized gas guide
  • Optimized valve plate system
  • External fan for motor cooling
  • Highly efficient electric motors of the latest generation
  • Replaceable motor

HA principle: Unmatched efficiency for low-temperature air-cooled compressors

Experience cutting-edge low-temperature air-cooled compressors with direct suction operation and efficient motor cooling. Unlike traditional methods, our compressors ensure the suction gas remains unheated by the motor, directly powering the compressor. Thanks to a compact ventilation unit, we achieve precise air cooling for the engine and cylinder heads.


  • Controlled gas temp for optimized performance.
  • Substantial performance boost.
  • Wider range of versatile applications due to innovative design.

UL recognized

The UL-HGe series seamlessly integrates the time-tested advantages of the suction gas-cooled HG series with rigorous safety standards tailored for the US and Canadian markets. These UL-recognized semi-hermetic compressors, expertly refined by Danfoss BOCK®, are a testament to energy efficiency, robustness, and compact design. Engineered for versatility, the UL-HGe compressors are your reliable choice across a wide spectrum of applications. 

HGZ two-stage compressors

Danfoss BOCK® builds on the HG series to create the HGZ two-stage compressor series for prolonged low-temperature cooling. It offers a 6-cylinder compressor, available in two versions, with optional medium-pressure mixing line or pre-mounted.

  • 3 capacity stages from 93.7 to 122.4 m³/h (50 Hz)
  • 6-cylinder version
  • LP/HP stage split in a ratio of 2:1
  • Two-stage operation with liquid subcooler
  • Post-injection valve matched to refrigerant and application
  • Particularly reliable and economical compressor concept

Looking for spare parts?

BOCKSHOP Spare parts catalog


The online spare parts catalog allows you to find the right spare parts and accessories for BOCK compressors and units with just a few clicks. 



Type Name Language Valid for Updated Download File type
Brochure HG, HA, HGZ semi-hermetic compressors English Multiple 15 Sep, 2023 51.6 MB .pdf


Compressor selection tools - VAP

The VAP tool is ideal for finding the appropriate compressors or units for stationary applications. By inputting the required refrigerating capacity and operating conditions, the tool will display compatible components right away. In the VAP tools you will also find additional details about the suggested compressors.

Related applications

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