Powerstream Screw

Reliable and versatile water-cooled chillers with screw compressors and dual refrigerant circuit designed to provide maximum thermal efficiency



Refrigeration solution with the best cost/functionality ratio

Equipped with the dual refrigerant circuit, Powerstream Screw chillers cover cooling capacity from 600kW to 1200kW with modulation in the range of 25-100%. Installed screw compressors feature slider control to achieve a high level of efficiency at loads of 60 to 100 percent.


Whether used in an industrial plant, commercial building, or data center, Powerstream Screw water chiller fits your unique requirements. Engineered to deliver maximum performance and combining a set of benefits such as sustainable design and low maintenance cost, Powerstream Screw chillers are proven performers with unsurpassed energy efficiency and the highest degree of reliability.

  • Screw compressors with slider capacity control

  • Enhanced part load efficiency

  • Feature-rich control software

  • High seasonal energy efficiency

  • Lower operating costs

  • Proven reliability

Features and advantages

Powerstream Screw chillers are equipped with premium quality, high-performance components, making it the most reliable choice for every application, be it high-availability data center, process cooling, or air conditioning

Design and components


Cost-efficient solution for both full and part load conditions

Powerstream's compact semi-hermetic screw compressors are distinguished by a further improvement in energy efficiency under full and part load conditions. As a result, these compressors exceed the international efficiency standard of compact screws with respect to the seasonally weighted energy requirements to an even higher degree than before. This results in particularly high ESEER/IPLV and SCOP values.


The cooling capacity of the compressor is controlled by a slider which allows an adaptation of the compressor displacement to the power requirement by shifting the start of the compression process through axial movements of the control slider. The slider, starting from the full load position (100%) can be positioned to nominal 75%, 50%, and 25%.


Adopted for part load conditions

Optimized for R134a refrigerant

Allows high evaporation temperatures

The shell and tube evaporator incorporated in Powerstream design offers extremely high evaporating temperatures for a given supply water temperature and optimized for R134a refrigerant. Heat transfer rate of the evaporator enhanced with internal refrigerant side tube grooving and optimally positioned baffles.


The tube bundle composed of a series of pre-modeled U-shaped tubes enabling the free expansion of the whole unit independently from the shell. Internal baffles in the water circuit optimize the flow whilst keeping pressure drop to a minimum. Reduced baffle spacing ensures high heat transfer at low flow rates, as well as for brine operation.


Optimized for R134a refrigerant

Enhanced performance

Ease of maintenance


Powerstream Screw features newly developed shell-and-tube condensers optimized for R134a refrigerant to provide the best possible efficiency. With high-performance tubes, new baffle design and shell, these condensers provide maximum efficiency with a low cost per kW, as well as a shorter length and reduced weight.


Powerstream Screw chillers are equipped with two refrigerant circuits each connected to its own shell-and-tube condensers. This design enhances reliability and allows chiller maintenance to be performed without shutting it down completely, as well as maintenance of a connected cooling tower or dry cooler. Therefore, 60% of the design capacity will remain in service during maintenance periods.


20% savings with electronic expansion valves


The electronic expansion valve (EEV) reduces the need for high head pressure when running at lower than nominal ambient conditions. EEV is controlled by a driver which regulates its opening according to the performance levels required by the system and guarantees minimal overheating based on all operating conditions. Due to the superior control characteristics of EEV, Powerstream chillers demonstrate energy savings of up to 25%.


Intelligent, centralized chilled water plant control

The control hub of Powerstream chillers is a sophisticated controller with advanced software developed for efficient operation of water-cooled chillers. It manages and optimizes the chiller’s performance, giving the complete control over the system for plant operator.


Control software can be directly linked to the existing building management system. Integration with a BMS permits the collection and analysis of the operating data of chilled water plant and helps to maintain optimal equipment settings, savings in energy, identification of trouble-prone areas, provision of maintenance schedules and the generation of safety and security alarms.


For the efficient operation of multiple units on a single chilled water plant, the sequencing software permits interlinked operation of the complete system, thus providing optimal temperature control and minimal energy consumption.

We recommend using Bora or Mistral series dry coolers with Powerstream chillers. These dry coolers are optimized for use in combination with water-cooled chillers, offer high performance and enable low water temperature difference.

Dry cooler selection

Bora series

The Bora series is well-suited for urban locations due to their low sound emission, as well as for high-polluted areas and coastal installation due to the high corrosion resistance of microchannel heat exchangers used in the unit design. For the installations in hot climate zones, we recommend Bora dry coolers with evaporative pads. When applied to HVAC and industrial systems, evaporative dry coolers provide extended operating range and compressor horsepower savings of up to 30 percent compared with traditional systems.

Mistral series

Mistral series dry coolers equipped with finned tube heat exchangers with internally grooved copper tubes and are ideal for any kind of industrial and commercial applications. These dry coolers are extremely robust, simple by design and perfect in the specification.


Cooling capacity



Up to 5.58


Up to 6.20









Heat recovery


Related products



High-capacity air-cooled chillers with inverter-driven screw compressors and microchannel condensing coils. Available with R134a and low-GWP, ozone-friendly R1234ze refrigerants

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Kaltra Innovativtechnik GmbH

Max-Reger-Str. 44
90571 Schwaig

Email: info@kaltra.de
+49(0)911 715 32021

VAT: DE300943964

Kaltra is a customer-focused developer and supplier of reliable, energy efficient thermal management equipment and solutions.


From the professionalism of our research and development engineers to the wide experience of our service team, we are dedicated to delivering you the best service possible.

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