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BITZER Launches New High-Efficiency Version of the CSW Compact Screw Compressors

BITZER presents its new CSW85/95 compact screw compressor with version 4 motor and ensures optimized efficiency in high-performance water-cooled chillers. The new selection of compressor motors allows manufacturers to meet the highest requirements in terms of efficiency.


The CSW version 4 engine is a combination of the well-known BITZER CSW screw compressor with a specifically selected version 4 engine and a special oil charge. This solution has already been successfully used on the Chinese market, guaranteeing high reliability and high efficiency in water-cooled chillers. Following the increase in efficiency requirements and the resulting demand from customers, especially from Europe and India, BITZER has now started the construction of its CSW at the BITZER headquarters in Rottenburg-Ergenzingen for the affected markets.


The number of water-cooled plants is increasing significantly in Europe - also due to the requirements of the Ecodesign Directive. CSW enables OEM screw chiller manufacturers to design and manufacture water-cooled A/C chillers that meet the highest international energy efficiency standards, such as European Ecodesign 2016/2281 Level 2 and Indian BEE-ECBC classification system - ISEER.


The product range includes nine models with displacement volumes between 410 m³ / h and 1.120 m³ / h at 50 Hz and 495 m³ / h and 1.351 m³ / h at 60 Hz. Their limits of use have been designed for high efficiency water-cooled process chiller and A/C applications, with maximum condensing temperatures up to 46 °C. For this reason, their technical concept includes various solutions to improve the efficiency of the compressor: The motor has an optimized efficiency within the target use limits and a reduced maximum operating current. This makes it possible to use smaller contactors and smaller diameters for the main cables, resulting in a reduction in overall plant costs. The CSW has been designed for medium and low GWP and low pressure refrigerants, such as R134a, R1234yf, R513A, R450A, R1234zeE and R515B. In addition, the internal gas flow has been optimized and the internal pressure drop further reduced.


The combination of CSW with version 4 engine and the optimized oil version makes it possible to meet the European standard EU 2016/2281 in terms of efficiency, for example in a water-cooled air-conditioning chiller; the CSW version 4 engine improves the Seasonal Energy Efficiency Ratio (SEER) by up to 8% compared to a standard CSW compressor, in the typical operating conditions of a motor-cooled chiller.


Mechanical capacity adjustment with the single spool valve concept can be set between 100 and 25%. This CSW version is also suitable for use with external frequency inverters at a frequency range between 20 and 60 Hz. The variable speed range depends on the operating conditions present and the input voltage range.


BITZER Launches New High-Efficiency Version of the CSW Compact Screw Compressors

Author, Riccardo Tigani   Linkedin Page
General Manager at Linea3C Srl

15th July 2021

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