Compressor Technology - Electric Air Brake Compressors

Air Brake Compressor Technology Comparison: Rotary Screw, Rotary Scroll & Reciprocating Air Compressors

Choosing the right air compressor for air brake systems can be a challenging task, especially when you’re faced with a variety of options. The three most popular air brake compressor options for electric vehicles are rotary screw, rotary scroll, and reciprocating compressors. All have unique functions, advantages, and disadvantages, which must be considered when choosing a technology.

Rotary screw compressors use two meshing helical screws to compress air. These compressors are known for their high efficiency and continuous operation capability, making them ideal for heavy-duty vehicle applications that require reliable air.

Meanwhile, scroll compressors utilize two spiral-shaped scrolls—one fixed and one orbiting—to compress air. They are valued for their quiet operation and compact design, making them suited for applications that require near-silence and small space claims. However, scroll compressors get extraordinarily hot, can struggle to keep up with air demand, and can be permanently damaged by intake contaminants.

Reciprocating compressors use a piston driven by a crankshaft to deliver air at high pressure. They are often chosen for applications where lower initial costs and unskilled maintenance are leading priorities.

Feature	Rotary Screw Compressor	Rotary Scroll Compressor	Reciprocating Compressor
CONTINUOUS OPERATION	✔ Ideal for heavy-duty use	✖ Prone to overheating with continuous use	✖ Requires bulky air receiver tanks to compensate
EFFICIENCY	✔ Highly efficient	✔ High efficiency	✖ Low efficiency
HEAT GENERATION	✔ Medium	✖ High	✖ High
MAINTENANCE	✔ Simple, cost-effective	✖ Complex, costly	✔ Simple, cost-effective
DURABILITY	✔ Extremely durable	✖ Limited under heavy-duty use	✖ Short lifespan
NOISE LEVELS	✔ Quiet	✔ Ultra-quiet	✖ Noisy
SPACE REQUIREMENTS	✔ Efficient use of space	✔ Very compact	✖ Larger footprint

Source: Altas Copco

Detailed Compressor Technology Comparison

Performance and Efficiency

Screw Compressors

Continuous Operation: Can run continuously without overheating, making them suitable for industries requiring constant air supply.
High Efficiency: Deliver higher volumes of compressed air and are more energy-efficient for large-scale operations.
Temperature Control: Generate less heat compared to scroll compressors, extending their lifespan and reducing cooling requirements.

Scroll Compressors

Intermittent Use: Best for applications where air demand is not constant, as continuous operation can lead to overheating.
Moderate Efficiency: While efficient, air output is limited making scrolls less capable than rotary screw compressors of handling mid-to-large air demands.
Heat Generation: Produce more heat which can impact their longevity and performance.

Reciprocating Compressors

High Pressure: Capable of delivering high-pressure air.
Lower Efficiency: Less efficient for continuous duty applications compared to screw compressors.
Temperature Control: Produce more heat due to their piston-driven mechanism, requiring effective cooling systems.

Maintenance & Durability

Screw Compressors

Easier Maintenance: Fewer moving parts lead to less wear and tear, simplifying maintenance processes and reducing total cost of ownership.
Durability: Designed to withstand harsh conditions, including extreme temperatures and heavy-duty cycles.

Scroll Compressors

Complex Maintenance: The intricate design makes inspection and repairs more challenging and costly.
Limited Durability: More prone to issues under continuous heavy-duty use due to higher heat generation, complex mechanisms, and risk of damage or failure caused by intake contaminants.

Reciprocating Compressors

Simple Maintenance: Straightforward design with easily replaceable parts, and no specialized maintenance training is required.
Low Durability: Known to need frequent maintenance and replacement due to component and system failures.

Noise and Space Requirements

Screw Compressors

Low Noise Levels: Equipped with noise-dampening technologies, they operate quietly with high performance.
Space Efficiency: Though typically larger, they are designed to be integrated into various industrial settings without occupying excessive space.

Scroll Compressors

Ultra-Quiet Operation: Extremely quiet, suitable for noise-sensitive environments like medical facilities and laboratories.
Compact Design: Smaller and can be placed in confined spaces, even closets, saving valuable floor space.

Reciprocating Compressors

High Noise Levels: Tend to be noisier due to their mechanical action and vibration, requiring soundproofing measures in certain environments.
Larger Footprint: Occupy more space, making them unsuitable for compact installations.

Why Choose Rotary Screw Compressors?

While all three compressor types have their merits, rotary screw compressors often come out on top for their efficiency, durability, and ability to handle demanding electric vehicle applications. Their low maintenance requirements and superior performance make them a cost-effective choice in the long run, despite the higher initial investment.

At VMAC, we offer application-engineered rotary screw compressors designed for electric trucks and buses. View our compressor specs to find the perfect solution for your EV needs and experience the benefits of choosing a high-performance, reliable air compressor.