Patented liquid-cooled scroll technology from Air Squared makes the efficient, quiet, and reliable performance of traditional oil-free scroll compressors available for high-pressure operation.

By introducing effective cooling to the fixed scroll and orbiting scroll, liquid-cooled scroll compressors are capable of operating 100% oil-free at higher pressure ratios and managing elevated temperatures over a wide-range of working fluids.

An oil-free scroll compressor requires tight running clearance between the orbiting scroll and fixed scroll to operate efficiently. As temperature increases with pressure throughout the compression process, mitigating thermal expansion with effective cooling is critical in an oil-free scroll design. While air cooling is adequate at lower pressure ratios, there are numerous benefits associated with liquid cooling at higher pressure ratios.

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100% Oil-Free
Maintain the purity of your system with oil-free scroll technology
Quiet, Smooth Operation
Dynamically balanced, valve-less, and nearly pulsation-free
Efficient, High-Pressure Performance
Liquid cooling for high-pressure operation with volumetric efficiency up to 90%
Sealed or Semi-Hermetic Design
Immersion protection and configurable for gases other than air
Reliable, Durable Solution
Extended life, long service intervals, and simple field maintenance
Compact, Lightweight Design
Space-saving cooling system and fewer moving parts than competing technology


  • Electric and Hybrid Bus
  • Air Braking System
  • Air Suspension System
  • Military Vehicle (Under-the-Hood)
  • Medical, Hospital, and Dental Air System
  • Industrial Air and Gas Processing
  • Natural Gas Booster
  • Nitrogen and Oxygen Generation

Liquid-Cooled Scroll Compressor Products and Projects

Find your oil-free solution through a growing line of liquid-cooled scroll compressors engineered specifically for OEMs and view past projects that supported liquid-cooled scroll technology development.

Liquid-Cooled Scroll Technology Products

P17H043B-AC-LC-7HP Liquid-Cooled Scroll Compressor


Max Pressure: 13 barg Max Flow: 430 lpmv

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P17H043C-BLDC-LC Liquid-Cooled Performance Series™ Scroll Compressor


Max Pressure: 12.5 barg Max Flow: 425 lpmv

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Liquid-Cooled Scroll Technology Projects

P09H014A-BLDC-SH-LC Oil-Free Scroll Refrigeration Compressor

Oil-Free Scroll Compressor for Space Refrigerator

November 09, 2020

Vapor-compression refrigeration systems commonly use widely-manufactured oil-lubricated scroll and reciprocating compressors to superheat saturated vapor from the evaporator and circulate to the condenser. For operation in space, however, a vapor-compression cycle requires an oil-free compressor solution, as the zero-gravity environment causes standard oil return mechanisms to fail. Intended to support the Zero-Gravity Vapor Compression Refrigerator […]

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V06H014A-BLDC-SH-LC Semi-Hermetic, Liquid-Cooled, Scroll Vacuum Pump

Scroll Vacuum Pump for the International Space Station

April 13, 2020

Highly efficient, lightweight, and compact, the V06H014A-BLDC-SH-LC scroll vacuum pump is designed to support environmental control and life support systems (ECLSS) on board the International Space Station (ISS). It is the second Air Squared design scheduled for space flight in 2020. The V06H014A-BLDC-SH-LC will replace peristaltic pumps used for in-situ urine processing. The compact design […]

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V16H034D-BLDC-H-LC Liquid-Cooled, All-Metal (LCAM) Scroll Vacuum Pump

Liquid-Cooled, All-Metal Scroll Vacuum Pump

May 01, 2018

After over a decade of collaboration with nuclear laboratories across North America, Air Squared has developed a liquid-cooled, all-metal (LCAM) scroll vacuum pump. The V16H034D-BLDC-H-LC LCAM scroll vacuum pump is capable of pumping 15 m3/hr and features integrated water or oil cooling. The patented liquid cooling integrated into the LCAM scroll vacuum pump increases operating […]

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P16H030E-BLDC-LC Liquid-Cooled Scroll Compressor

Quiet, High-Pressure Compressor for Commercial EV

April 28, 2018

Air Squared has completed development of a liquid-cooled scroll compressor for a commercial electric vehicle application. The application required a durable, oil-free compressor capable of delivering 150 lpmv at 10.5 barg. A major source of noise for EV applications is the compressor used in the air-braking system, so quiet operation was also a critical requirement. […]

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P16H043E-AC-LC Liquid-Cooled Scroll Compressor

Liquid-Cooled Scroll Compressor for Electric Bus

April 02, 2018

Continuing development of its patented liquid-cooled scroll technology, Air Squared has completed a custom scroll compressor for an electric bus application. The application required an oil-free air compressor capable of delivering 350 lpm v at 10.5 barg with nominal sound levels below 50 dB(A). With growing populations in urban centers around the world, cities looking […]

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P32H076A-BLDC-LC Liquid-Cooled Scroll Compressor for Fuel Cell

Liquid-Cooled Scroll Compressor with Integrated Motor for Fuel Cell Vehicles

January 22, 2016

Fuel cell applications require oil-free air to prevent contamination of the fuel cell stack. When a major automotive company approached Air Squared in search of an oil-free air compressor, they knew they would find the compact, reliable, efficient, and oil-free product needed for a fuel cell-powered vehicle. Providing 700 SLPM of air at 3 barg, […]

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P32H080A-AC-SH-WC Semi-Hermetic Scroll Compressor with Water Cooling

Semi-Hermetic Scroll Compressor with Integrated Water-Cooling

January 02, 2015

Designed for an industrial gas processing application with high-sensitivity to any contamination of the working fluid, the oil-free P32H080A-AC-SH-WC is capable of compressing helium from 1 bara to 3.5 bara at a flow rate of 1,500 lpmv. The novel scroll compressor incorporates two innovations patented by Air Squared – semi-hermetic design using a magnetic coupling […]

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Stainless Recirculation Pump

Stainless O2 and H2 Recirculation Pump

March 14, 2010

The stainless steel hydrogen and oxygen recirculation pump was developed for Lockheed Martin’s ISIS program as part of the on-board fuel cell system. Excess electricity provided by the photovoltaic cells during the day is used to convert water into oxygen and hydrogen, which is used by the fuel cell system to power the dirigible during […]

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P18H36N6.25 High-Pressure Water-Cooled Scroll Compressor

High-Pressure Water-Cooled Compressor

September 01, 2007

The world’s first water-cooled scroll unit was designed for the US Army to fit inside a military vehicle with a small envelope and no available air cooling. The unit is water-cooled using a bellows to transfer coolant around the orbiting scroll. The patented design uses a BLDC motor and delivers approximately 350 lpm of air […]

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Liquid-Cooled Scroll Technology News

Concept Rendering of Second-Generation Spinning Scroll Boost Compressor for NASA Spacesuit Development

Spacesuit Spinning Scroll Boost Compressor Development Continues

June 24, 2020

Broomfield, CO – After successfully completing feasibility testing in 2019, Air Squared has received small business innovation research (SBIR) Phase II funding from NASA to continue the development of its pressure swing adsorption CO2 and H20-removal spinning scroll boost compressor (SSBC). Following the topic Exploration Portable Life Support System (xPLSS) for deep space and surface […]

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The S351 Dry Combat Submersible Prototype

Comparative Study on Decompression Pumps for Dry Combat Submersible

August 23, 2019

USSOCOM is investigating the achievable possibilities to depressurize dry combat submersible (DCS) hyperbaric spaces while at diving depth. Regulating decompression on ascent following underwater activity significantly decreases the risk of oxygen toxicity, nitrogen narcosis, and decompression sickness. Existing crewed decompression is achieved via surface decompression or staged decompression obligations; however, surface decompression requires supplemental shipboard […]

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Large-Scale Liquid-Cooled, All-Metal (LCAM) Scroll Vacuum Pump

Liquid-Cooled, All-Metal Scroll Vacuum Pump Awarded Phase II Funding to Support Fusion Project

October 10, 2018

Following a success Phase I Small Business Innovative Research (SBIR) effort to develop a small-scale (15 m3/hr) liquid-cooled, all-metal (LCAM) scroll vacuum pump compatible with radioactive Tritium, the Department of Energy (DOE) has awarded Air Squared Phase II funding to develop a full-scale (150 m3/hr) LCAM scroll vacuum pump by 2020. The award is funded […]

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All-Metal, Hermetic Scroll Vacuum Pump with Integrated Liquid Cooling

All-Metal Scroll Pump Development Continues

August 02, 2017

Broomfield, CO — Air Squared has been awarded Phase I Small Business Innovation Research (SBIR) funding through the US Department of Energy (DOE) under the topic Advanced Technologies and Materials for Fusion Energy Systems. The development is a continuation of an Air Squared internal development that resulted in an air-cooled, all-metal scroll pump with 15 […]

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Fuel Cell

Development for Fuel Cell Recirculation Pumps

August 12, 2011

High-reliability oxygen and hydrogen fuel cell recirculation pumps for a lighter-than-air aircraft application.

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Custom Scroll Design

Contact Air Squared to learn how a custom liquid-cooled scroll compressor can support your application by providing the most advanced oil-free, high-pressure compressor solution available.

Advanced Custom Design Capability with Liquid-Cooled Scroll Technology

For over twenty-five years, Air Squared has continuously challenged the limits of possibility with scroll technology. With the intoduction of patented liquid-cooled scroll technology and an ever-expanding range of custom design capability, put our innovations to work in your application.

Oil-Free Scroll Design

Orbiting scroll technology offers a quiet oil-free alternative to traditional technology like piston, diaphragm, and vain.


With patented liquid-cooled scroll technology, scroll compressors can now be designed for pressure ratios that were previously unattainable.

Gases other than Air

With several patented sealed and semi-hermetic configurations, liquid-cooled scroll compressors can be designed for compatibility with a wide-range of working fluids.

Elevated Temperatures

With highly effective liquid cooling, scroll compressors can be designed to withstand harsh temperatures and enviormental conditions.


When minimal power consumption is critical, leverage the inherent efficiency advantage of scroll technology.

Compact Footprint

Liquid cooling allows for a compact scroll compressor design that can fit in tight envelopes without sacrificing reliability or performance.

Liquid-Cooled Scroll Technology Explained

Liquid-cooled scroll technology significantly expands the performance capability of oil-free scroll compressors. This is the best place to start for a basic understanding of the technology behind liquid-cooled scroll designs and how it can support your application.


Range Capability

Flow Rates 100 – 3,000 lpmv
Pressures 5 – 15 barg
Volumetric Efficiency Up to 90%

Fluid Compatibility

By Configuration

Standard Air
Semi-Hermetic Feedthrough CO2, He, N2, CO, and Argon
Independent Drive H2, O2, Natural Gas

While liquid cooling for oil-free and lubricated scroll compressor has been investigated in the past, patented liquid-cooled scroll technology from Air Squared offers the first oil-free scroll compressor design that provides effective cooling to both the fixed scroll and orbiting scroll. The patented technology allows coolant to be transferred between the fixed scroll and orbiting scroll without the use of dynamic seals.

Liquid-Cooled Scroll Compressor Demo

Air-cooled scroll compressor designs are pressure-limited because the heat generated during compression causes the primary working components to thermally expand. The thermal expansion causes interference between the fixed scroll and orbiting scroll, eventually leading to mechanical failure. While the running clearance between the fixed scroll and orbiting scroll can be increased to avoid interference, this approach also decreases volumetric efficiency and pressure capability.

Liquid cooling allows for significantly more control over operating temperatures throughout the compression process. By removing heat generated during the compression process more effectively, thermal expansion is mitigated, allowing for high-pressure operation without sacrificing efficiency or reliability.

Sealed and Semi-Hermetic Configurations

Compared to air-cooled scroll compressor designs, liquid cooling offers superior isolation of working fluid to ambient and drive componentry (i.e., motor). Air-cooled compressors cool the fixed scroll and orbiting scroll with ambient air. While this approach is adequate with an open-housing compressor design, air cooling is far less effective if the compression process is fully enclosed (e.g., sealed or semi-hermetic). Liquid-cooling solves this issue by providing highly effective cooling to the fixed scroll and orbiting scroll, even if the compressor is semi-hermetically sealed.

Liquid cooling also operates independently of ambient conditions. This allows for effective cooling even if the compressor is exposed to elevated ambient temperatures – as in under-the-hood vehicle applications.

For operation with flammable gases, such as O2 and H2, the “independent drive” series of liquid-cooled scroll compressors are easily configured with a magnetic coupling that fully isolates the working fluid from the motor.

Drive Configurations

Air Squared offers two drive configurations for liquid-cooled scroll compressor designs.

Integrated Drive Series

The integrated drive configuration uses a liquid-cooled BLDC motor. With liquid cooling available to the motor, as well as the compressor head, liquid-cooled scroll compressors with an integrated drive configuration are more efficient and compact.

With the cooling system fully integrated with both the motor and compressor head, custom motor requirements are difficult with an integrated drive configuration. Operation with flammable gases is also not recommended, as the motor is not isolated from the working fluid.

Independent Drive Series

The independent drive configuration is ideal for customers with custom motor requirements or operation with flammable gases. The independent drive configuration removes all rotating radial loads on the motor bearings, leaving only the torque radial loads. This allows for flexibility in motor selection, as well use of a magnetic drive coupling that fully isolates the motor from the working fluid.

Cooling Loop Integration

If your application requires an independent cooling loop, Air Squared offers integration of a single-phase liquid cooling loop, which includes all necessary hardware to circulate the coolant and discharge thermal energy.

Liquid-cooled scroll technology from Air Squared has a size, efficiency, reliability, noise, and sealing advantage over air-cooled designs. With axillary components (e.g., cooling fins, fans, ducting) no longer necessary, the size and part-count of the compressor are substantially reduced. By running the coolant in close proximity to the compression process, an order of magnitude more heat can be removed during the compression process, which allows more isothermal compression for increased efficiency. The coolant also provides a thermal barrier between the compression process and bearings. This allows the bearings to run much cooler for vastly improved reliability. Because the compressor does not rely on ambient air to directly cool the fixed scroll and orbiting scroll, the compressor housing is enclosed, which offers protection against dust and debris, as well as reduced noise.