What is a Dual Speed Compressor?
Previously, screw compressors were categorised into two main groups: fixed speed and variable-speed drive (VSD). But in 2023, Atlas Copco introduced the first dual-speed rotary screw compressor.
This article explains what a dual-speed compressor is.
A dual-speed screw compressor runs at two different speeds. Like fixed-speed compressors, one of the speeds gives maximum compressed air output when needed. But it also has a lower speed when the demand for air reduces.
Table of Contents
Discover the GA Series of air compressors
Compressor Types
Compressed air systems are crucial in various industries, and choosing the right compressor type is essential for optimal performance and energy efficiency.
There are three primary types of compressors:
- fixed-speed
- dual-speed
- variable-speed
Each type has unique characteristics, advantages, and disadvantages.
Fixed-speed air compressors operate at a single speed, providing a constant output of compressed air. They are straightforward and reliable but can be inefficient due to continuous on/off cycles consuming more energy during periods of low air demand.
On the other hand, dual-speed air compressors offer two speeds: a high speed for maximum air output and a low speed for reduced energy consumption. This flexibility delivers substantial energy savings.
Variable-speed air compressors are the most advanced and can match their speed to the demand for air in real time – this precise control over motor speed results in optimal energy efficiency.
What is a Dual-Speed Compressor and How Does it Work?
Dual-speed air compressors have two motor speeds to control air output. A dual-speed drive train allows them to switch between high speed for maximum air output and low speed to save energy when less air is needed. When the demand for air is high, the compressor operates at full capacity and delivers maximum airflow. When demand drops, the compressor slows down the motor to save energy and prevent wear on parts.
Benefits of Dual-Speed Compressors
- Energy savings: operate at two speeds to match air demand, cutting energy costs.
- Reduced losses: unlike fixed speed models, they minimise energy waste by slowing down during low demand.
- Flexible pressure: adjust pressure settings without losing airflow, potentially using smaller-sized compressors.
- Lower maintenance: less wear on parts means fewer repairs and a longer lifespan.
- Cost-effective: balance between efficiency and cost, great for changing air needs.
Energy savings
Dual-speed air compressors save energy by adapting their motor speed to match the air demand. When the demand for compressed air is high, they run at full speed, delivering the necessary air output. But when the demand drops, the compressor slows down, reducing energy consumption. By using only the energy needed, dual-speed compressors lower energy bills.
Lower transient losses
A dual-speed compressor tackles these issues by starting against pressure and using less energy to produce air. The Atlas Copco GA FLX 11-30 model is engineered to deliver optimal flow at different pressures, ensuring efficient air delivery while consuming less energy. It minimises blow-off losses by not venting as much air as a fixed-speed air compressor. Additionally, it runs at a lower motor speed while unloading. A dual-speed air compressor can save 20% more energy than a fixed-speed model.
Multiple pressure settings
Another benefit of a dual-speed compressor is that, unlike other fixed-speed compressors, you can choose any pressure without compromising air flow or free air delivery (FAD). This means it can run efficiently at multiple pressure set points. This flexibility might allow you to choose a smaller dual-speed compressor instead of a fixed-speed one and save on capital and operational costs.
Less maintenance
Dual-speed air compressors lower maintenance costs because the motor speed adapts to demand, reducing strain on components. By slowing down during low air demand, they experience less wear and tear, leading to fewer repairs. This flexibility helps extend the compressor’s lifespan, saving operators money on maintenance.
Cost-effective
Dual-speed compressors provide cost savings by lowering energy use during periods of low air demand and minimizing maintenance requirements, resulting in long-term savings despite a higher initial cost.
Comparison of Different Air Compressor Types
Here is a quick comparison of single-speed, double-speed, and variable-speed drive (VSD) compressors.
| Type of Compressor | Pros | Cons | Unique Features | Benefits |
| Fixed-Speed (Single-Speed) | Most affordable initial investment cost Simple operation | High energy waste during off-load periods Inefficient due to continuous on/off cycles | Run at 100% capacity when loaded Consumes 35% of energy when off-load without producing air | Suitable for applications with consistent air demand |
| Dual-Speed | More energy efficient than single-speed Reduces off-load energy use by 20% Fewer parts, reducing maintenance issues | Higher initial cost than fixed-speed May not save much energy if air demand is stable or used in short bursts | Can slow down to minimum speed and off-load to conserve energy | Energy savings over time with a payback period of around two years Ideal for varying air demand |
| Variable-Speed | Highly energy-efficient Adjusts motor speed to match air demand Lower wear on internal parts | Highest initial purchase cost Only cost-effective for operations with fluctuating air demand | Modulates speed between 20% and 100% capacity to match air demand | Significant long-term energy savings ROI under 6 months Operates like a dimmer switch for air pressure control |
Dual-Speed vs Variable-Speed Compressors
Dual-speed compressors offer a great alternative to fixed-speed and variable-speed drives, providing significant energy savings and sustainability benefits.
Variable-speed compressors adjust motor speed to match air demand to minimise energy consumption and reduce wear on internal components.
Although dual-speed compressors can slow down to a minimum speed and offload to conserve energy, they are less efficient than variable-speed compressors. They still offer significant energy savings compared to traditional fixed-speed compressors, however.
The choice between a dual-speed or variable-speed compressor depends on the specific application, air demand, and energy consumption patterns. A variable-speed compressor may be the best choice for highly variable air demand operations. However, a dual-speed compressor is a cost-effective and energy-efficient option for applications with moderate variations in air demand.
Why You Will Love the GA FLX
- 20% energy saved
- Reduces total operating costs
- Variable pressure settings without sacrificing airflow
- 50% smaller footprint than GA fixed speed
- Custom performance settings
- Atlas Copco’s reliability, quality, and energy efficiency
The GA FLX dual-speed compressor cuts down on energy waste, known as transient losses. What are transient losses? These are energy losses that occur when a fixed-speed compressor starts and stops. A fixed-speed compressor can waste 20% of energy because of these losses, as it has to run at a minimum speed even when not producing air. The GA FLX can start up quickly under pressure and minimises energy losses thanks to its advanced technology.
Applications of Dual-Speed Compressors
Manufacturing
For factories where air requirements change throughout the day. They adjust speed to match needs, save energy, and keep operations running smoothly.
Automotive
A reliable and efficient air supply in vehicle assembly lines for tools that need varying air pressure.
Healthcare
In hospitals, where medical equipment needs a constant air supply, they adjust to keep the correct pressure to ensure the smooth running of critical medical devices.
Food and Beverage
Clean, dry air is critical in food production. Dual-speed compressors meet these demands by adjusting to changing air requirements and guaranteeing safe and efficient processes.
Construction
Dual-speed air compressors provide better tool performance and energy savings on site by adjusting speed to the task.
Choosing the Right Compressor
Choosing the right compressor means weighing energy efficiency, cost, and air pressure needs. Variable-speed compressors are the most energy-efficient but cost more upfront. They are ideal for jobs with changing air demand since they adjust speed to match output needs.
Dual-speed compressors strike a balance between efficiency and cost. They save more energy than fixed-speed models and work well for varying air demands. Though pricier than fixed-speed compressors, they often pay for themselves quickly through energy savings.
Fixed-speed compressors are the least efficient but cheapest. They are best for consistent air demand, running at full capacity without frequent stops.
Need help? Speak with one of our experts to find the right balance of performance, efficiency, and cost.
Design and Installation Considerations
Consider these key points for top performance and efficiency when setting up a compressed air system.
Make sure the compressor goes in a well-ventilated spot to avoid overheating and extend its life. Proper ventilation keeps the compressor cool and running smoothly.
Design the piping system to reduce pressure drops and maintain optimal air delivery at every pressure set point. Choose the right materials and sizes for efficient airflow.
Regular maintenance is crucial. Replace air filters, check oil levels, and clean components to keep the compressor in good shape. Scheduled maintenance prevents breakdowns and ensures efficiency.
Control Gear’s trained technicians are the best option for maintenance to keep the compressor running efficiently. Proper design, installation, and upkeep lead to significant energy savings and better performance.
Dual-Speed Compressors – Saving Energy Without Breaking the Bank!
This article explained what a dual-speed compressor is. This completely new compressor type offers many benefits, with energy savings being the most significant. Contact our experts at Control Gear to discuss Atlas Copco compressors.