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Direct Drive Rotary Screw Compressors

Superior Efficiency
With Kaeser’s one-to-one drive, the airend is directly connected to the motor via a maintenance-free coupling that eliminates transmission losses. Kaeser’s direct drive screw compressors deliver outstanding performance and increase energy savings. Kaeser uses oversized airends specifically selected to produce the required output in flow and pressure.  Compared to compressors using small, high-speed, gear-driven airends, the one-to-one drive provides significant savings.


Models: ASD / BSD / CSD / DSD / ESD / FSD series
Horsepower: 25-450 hp
Capacities: 72-2015 cfm
Standard pressures 80-217 psig



Performance Verification Program
Energy efficiency has been tested and confirmed by an independent laboratory as part of the Compressed Air and Gas Institute’s Rotary Screw Compressor Performance Verification Program. Kaeser compressors are up to 30% more efficient than some competitors’ models. See our CAGI data sheets.


The energy-saving Sigma Profile airend
Single-stage, flooded rotary screw airends deliver pressures up to 217 psig and feature the power-saving Sigma profile design. Airends are precision-machined and optimized in size and profile to mtach the airend speeds with their best specific performance. Unlike the competition, Kaeser Compressors makes many different airends so that we can apply them at their optimal speed and performance.



Energy-saving one-to-one drive
The motor is directly connected to the airend with a one-to-one coupling, providing maximum transmission efficiency. This true direct drive eliminates complex gear drive components, along with heat and power losses. It is also maintenance free, increasing reliabilty and uptime.



Sigma Control 2
The compressor control system features an industrial-based PC with update capabilities, Intel® microprocessor, and real-time operating system. Pre-loaded control profiles are available to precisely match compressor performance to air demand. A convenient SD card slot enables easy software upgrades and stores key operational parameters to minimize service costs, provide back-up capability, and offer long-term data storage for trending and analysis purposes.



Premium efficiency drive motor
Premium efficiency TEFC motors with class F insulation for extra protection from heat and contaminants. 460 or 575V 3-phase, 60 Hz. Other voltages are available.



Split cooling design
Two separate cooling air inlet zones for the coolers and drive motor ensure optimum cooling. Drawing ambient air directly across the coolers and motor through separate zones eliminates pre-heating and results in longer lubricant life and a cooler running motor. This also results in much lower approach temperatures, improving moisture separation and air quality.



Integral Moisture Separator

A moisture separator is integrated into the stainless steel discharge piping. This unique design maximizes separation with minimal pressure loss. A zero loss Eco-Drain is standard to automatically remove the captured moisture.



Electronic Thermal Management System

The innovative Electronic Thermal Management system dynamically regulates fluid temperature to avoid internal condensation build-up, eliminating a common cause of lubricant degradation.



Heat Recovery Ready

Compressing air converts the electrical energy you pay for into heat. The ASD to CSD series are available with a heat recovery option to easily recover up to 76% of this energy. You can harness addtional heat recovery by ducting exhaust air. In all, 9% of input energy is recovered as heat.

The ASD series can come ready to be connected to an internal plate-type heat exchanger; The BSD and CSD seris can be connected to an external heat exchanger or they can come with internal stainless steel plate type heat exchangers.

SeriesRated Motor PowerCapacity at 125 psig
ASD 25 / ASD 30 / ASD 40S / ASD 4025 hp to 40 hp112 cfm to 191 cfm
BSD 40 / BSD 50 / BSD 6040 hp to 60 hp193 cfm to 288 cfm
CSD 60 / CSD 75 / CSD 100S / CSD 100 / CSD 12560 hp to 125 hp290 cfm to 565 cfm
DSD 125 / DSD 150 / DSD 175 / DSD 200 / DSD 250125 hp to 250 hp569 cfm to 1003 cfm
ESD 250 / ESD 300250 hp to 300 hp1261 cfm to 1501 cfm
FSD 350 / FSD 400 / FSD 450350 hp to 450 hp1522 cfm to 1990 cfm
HSD500 hp to 600 hp816 cfm to 3044 cfm