A Complete Guide to Scroll Compressors - Atlas Copco USA

Sep. 01, 2025

A Complete Guide to Scroll Compressors - Atlas Copco USA

A Complete Guide to Scroll Compressors

Displacement Compressors Scroll compressors Compressor Types Air compressors Compressed Air Wiki

If you want to learn more, please visit our website Leling.

What are scroll compressors?
Working principle
Explanation of Parts
Advantages and Disadvantages
Choosing a scroll compressor?
Applications and Uses
Use in Dentistry

To understand the different types and technologies of compressors, we first need to understand the two basic principles of compressing air. These are dynamic and displacement compression. In this article, we talk about the scroll compressor. This is a type of displacement compressor with wide applications in air-conditioning and refrigeration systems, heat pumps, and cars.

A scroll compressor, also known as a spiral compressor and a scroll pump, is a type of positive-displacement compressor. It works through the internal compression of air or gas. Scroll compressors can be oil-lubricated or oil-free. The latter is best suited for applications where there is a need for clean, dry air quality without any oil contamination in the compression chamber.

Watch the video to learn more!

How do scroll compressors work?

Scroll compressors use two spiral-shaped scrolls to compress air. One scroll remains fixed, while the other moves in an orbiting motion around the center of the stationary scroll. As the scrolls rotate, the orbiting scroll draws air through the inlet, compressing and pushing it towards the center. Finally, the compressed air is released through the outlet.

Scroll compressors consist of two spiral-shaped scroll elements that are bolted together: a stationary scroll and an orbiting scroll driven by a motor. The process of compressing air in a scroll compressor involves several steps:

Oscillation: The scrolls oscillate in a continuous motion without metal-to-metal contact, compressing air in crescent-shaped pockets.
Orbiting Scroll Motion: The orbiting scroll, driven by a short-stroke crankshaft, moves eccentrically around the fixed scroll, creating suction that draws air in from the inlet at the top of the housing.
Compression: Air captured in pockets between the scrolls is gradually compressed as it moves toward the center.
Discharge: Compressed air is discharged from the outlet port at the center, where a non-return valve prevents backflow.
Stability: The 180° phase displacement provides radial stability, and the internal compression minimizes leakage due to lower pressure differences between air pockets.

By following these steps, scroll compressors achieve efficient and reliable air compression.

Cooling Fan: Helps dissipate heat generated during the compression process, ensuring the compressor runs efficiently and prevents overheating.
Suction Chamber: The area where air or gas is initially drawn into the compressor.
Suction Opening: The inlet through which air enters the suction chamber.
Delivery Opening: The outlet through which compressed air or gas is discharged from the compressor.
Fixed Scroll: The stationary spiral element that helps form the compression chamber.
Orbiting Scroll: The moving spiral element driven by a motor, responsible for compressing the air by orbiting around the fixed scroll.
Fail-Safe Temperature Sensor: A safety feature that monitors the compressor’s temperature to prevent overheating and potential damage.
Compression Chamber: The space between the fixed and orbiting scrolls where the air is compressed as the orbiting scroll moves.

When most people think of air compressors, they probably imagine a bulky and loud machine. Scroll compressors are pretty much the opposite of that. They are oil-free, compact and relatively silent compared to other types of compressors.

Thanks to the simple design of the scroll compressor with only one moving part, this type of compressor is highly reliable and quieter compared to the piston and rotary screw compressor. This makes them perfect for sensitive working environments, like a dentist’s office. Another advantage of scroll compressors is energy efficiency.

Advantages:

High Efficiency: Less energy consumption.
Quiet Operation: Lower noise levels.
Compact Design: Space-saving and easy to install.

Disadvantages:

Cost: Higher initial cost compared to other compressors.
Capacity Limitations: Not suitable for high-capacity applications.

Efficiency

Similar to internal compression in a screw compressor, the amount of internal compression is determined by the discharge port. Due to the unique design of the discharge port, the scroll air compressor can compress more air or gas while using minimal power.

Compared to other compressors, these machines attain the highest efficiency level by volume. This is because there are no pistons to compress the gas.

Noise

The noise emission of a scroll air compressor is significantly lower than other compressors. The complete compression cycle takes 2.5 turns, including the suction, compression, and discharge revolution phases. These occur simultaneously while providing a constant flow of pulsation-free air.

The scroll air compressor offers smooth and vibration-free operations thanks to its scroll element. It hardly has any torque variation compared to a piston compressor. The simple design of the scroll air compressor contains only one moving part. This makes it highly reliable and quieter than equivalent piston and rotary screw compressors.

Selecting a scroll air compressor involves considering several factors: size, flow, and air quality requirements.

Determine Needs:

Size & Technology: Identify the correct size and technology for your application.
Air Quality: Decide between an oil-free or lubricated compressor based on air quality needs.

Capacity & Flow:

The company is the world’s best electric scroll compressor supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.

For higher capacity and flow, units with multiple scroll elements (two or four) can be chosen.
It may be more economical to use a single large compressor instead of multiple smaller ones.

Key Features

Reliability: Fewer components than reciprocating compressors ensure high operational reliability.
Low Maintenance: These machines require minimal maintenance.

Modular scroll compressor

Scroll compressors with variable flow technology incorporate the benefits and flexibility of a modular system. They utilize two to four compressor modules integrated into one canopy.
Additionally, the Elektronikon® controller continuously monitors the status of each element and starts and stops the compression elements. This ensures that the compressed air output matches the air demand.
Moreover, the air quality and user-friendliness of these units guarantee a smooth production process.

Digital scroll compressor

On the other hand, the digital scroll compressor has a mechanical design. This machine matches the output of the compressor to the cooling requirements of the complete process.
The digital scroll compressor is mainly used in refrigeration and air-conditioning systems. They ensure precise temperature control in these applications. When temperatures are kept stable during the transportation of food, for example, this results in better food quality.

Scroll compressors are widely used in various industrial applications due to their efficiency and reliability. They meet the basic requirements of a general-purpose compressor and are commonly used in the food, refrigeration, air-conditioning, and transportation industries. For larger volume demands, oil-injected screw compressors may be more efficient.

Where are they typically used?

Laboratories & Research: Instrument calibration, sample analysis, and environmental control in cleanrooms.
Medical & Healthcare: Providing clean air for ventilators and incubators, powering surgical tools, and assisting in breathing during surgery.
Food & Beverage: Food packaging and vacuum sealing, meat processing, and carbonation.
Electronics: Parts cleaning, maintaining cleanroom environments, and preventing moisture and corrosion in precision assembly.

There is an abundance of applications for quiet and energy-efficient compressors that produce absolutely clean air. Take the SF scroll compressor series from Atlas Copco, which has been a leader in this field for more than 60 years. Its unique characteristics make it ideal for many manufacturing processes for which clean, oil-free compressed air is a prerequisite. That is why the SF is the preferred choice for sensitive indoor environments, like hospitals but also labs, breweries, bakeries, dairy farms, electronics manufacturing, and even lens production.

The SF series features a capacity range of 1.9 to 7.6 l/s (4.03 to 16.10 cfm), a maximum working pressure of 10 bar (145 psi), and a dew point performance as low as 2°C/36°F. Its air-cooled scroll element ensures efficiency, reliability, and durability, while the premium efficiency IE3 class motor lowers energy consumption. Most importantly, the SF series produces absolutely clean air.

Atlas Copco’s oil-free compressors, certified ISO -1 Class 0, set a new standard in air quality, exceeding testing requirements. These features make the SF series indispensable in maintaining a pleasant and hygienic environment in dentist offices, contributing to a less unpleasant visit for patients.

A Complete Guide to Scroll Compressors - Atlas Copco USA