Oil-free Air and Trouble-free Performance
For food and beverage, chemical, pharmaceutical, and other industries with stringent air quality requirements, KAESER offers a complete line of oil-free rotary screw air compressors.
Our CSG, DSG, and FSG oil-free air compressor series deliver oil-free air and follow Kaeser's core design principles of reliability, service-friendly design, and energy-efficient operation.
Available both air and water-cooled, with integrated dryer options, Kaeser oil-free compressors help reduce costs with components designed for quality and performance, arranged for maximum accessibility, and with smart features to reduce maintenance time.
For short-term or mobile requirements, we offer our M500-2 diesel-driven MOBILAIR, delivering 1600 cfm.
Where Oil-Free Rotary Screw Air Compressors Are Critical
Certain industries cannot tolerate even trace oil contamination in their compressed air supply. In food and beverage production, compressed air contacts products at multiple points on the line, from sorting and ejecting to mixing, packing, conveying powdered ingredients, and cleaning bottles and molds before filling. Any oil in that air creates compliance exposure and product liability risk.
Pharmaceutical and life sciences facilities face equally strict requirements. Drug manufacturing and medical device production demand purity that meets ISO 8573-1 Class 0 or Class 1 for oil, specifications that only a true oil-free compressor can achieve without depending entirely on downstream filtration.
Chemical processors need oil-free air to maintain product purity and prevent catalyst and process equipment fouling. Semiconductor manufacturing requires extremely high-purity air where even microscopic particles can cause defects, while automotive and aerospace paint finishing and precision assembly operations rely on contamination-free air to prevent surface defects on high-value components.
Built for Efficiency, Reliability, and Serviceability
Purchasing an oil-free air compressor is a long-term decision. The sticker price accounts for a fraction of total lifecycle cost. Energy consumption dominates over time, which is why Kaeser engineers every detail of the CSG, DSG, and FSG series with efficiency in mind.
Energy Efficiency
Kaeser's oil-free rotary screw compressor models are up to 9% more efficient than competing designs. SIGMA FREQUENCY CONTROL (SFC) models use synchronous reluctance IE5 motors, and a speed-controlled radial fan on fixed and variable speed units maintains proper cooling airflow while minimizing power draw. For operations needing sub-freezing pressure dew points, our patented i.HOC (Integrated Heat of Compression) dryer achieves dew points as low as -22°F. The i.HOC uses 100% of the heat generated during the second compression stage for drying, making it effectively available at no additional energy cost. For facilities focused on sustainability, up to 96% of electrical energy input can be recovered as hot air or heated process water, with payback periods of less than a year.
Reliability
The rotors carry a special abrasion-proof coating rated to 575°F that will not wear over time, keeping compressed air delivery and energy consumption consistent across years of operation. Stainless steel rotors in the second compression stage ensure air quality and significantly extend service life. SIGMA CONTROL monitors more than 20 critical operating parameters, stores the last 200 operational events, and offers multiple control profiles to match compressor behavior precisely to process demand.
Serviceability
In the CSG series, service intervals for compressor stages and gear fluid are 50% longer than in previous designs, condensate drain maintenance intervals are three times longer, and the pulsation dampeners are maintenance-free. On larger models, both stages of the aluminum-block heat exchanger swivel out for cleaning, and the temperature-controlled standstill fan removes residual heat during standby, allowing the main fan to be switched off for quicker service access.
Air-Cooled or Water-Cooled: Choosing the Right Configuration
Kaeser oil-free rotary screw air compressors are available in both configurations. Air-cooled models work where cooling water infrastructure is absent or impractical, are available up to 450 hp, and feature heated exhaust air that can be ducted directly to an adjacent space for heating without auxiliary fans.
Water-cooled models are the better fit for space-constrained installations: their compact footprint and small exhaust air duct allow placement in smaller, low-ceilinged compressor rooms. For those organizations who require heat recovery for their process, there is no better option than a water-cooled, oil-free screw compressor. Furthermore, the efficiency of the oil-free screw compressor will increase with the water-cooled option. In general, air-cooled versus water-cooled compressors can be summed up in this Kaeser blog post.
Both configurations are available with integrated dryers and SFC variable-speed drive variants. Browse our 50–125 hp and 125–450 hp series pages for full specifications, or shop by horsepower to find your fit. For temporary or mobile needs, the diesel-driven M500-2 MOBILAIR (only available air-cooled) delivers up to 1,600 cfm without fixed infrastructure. For application-specific guidance, visit our compressed air applications page.
Get the Right Oil-Free Compressor for Your Operation
From 50 hp to 450 hp, we engineer Kaeser oil-free rotary screw air compressors to keep your most critical processes running cleanly and efficiently, backed by factory-trained service technicians and a 24-hour emergency parts guarantee. Tell us about your application, your required flow rates, and pressures, and our compressed air system experts will identify the configuration that fits your exact requirements. Request a quote today and put Kaeser's decades of compressed air engineering experience to work for your operation.