What is a VSD Variable Speed Drive Air Compressor?
If you are in the market for a new compressed air solution, you may be wondering whether to pick a variable speed drive compressor or a fixed speed compressor instead.
Well, we have all the information you need in this handy guide – read on to find out everything you need to know about variable speed drive compressors and how to make your compressed air system work hard for you.
Table of Contents
What Are Variable Speed Drive Air Compressors?
Industries with fluctuating compressed air needs are increasingly turning to variable speed drive (VSD) compressors. These systems match the compressor’s motor speed to the precise, real-time air demand. VSD compressors, such as the Atlas Copco GA VSD+, offer advanced control systems that ensure efficiency by dynamically adjusting to changes in air requirements.This flexibility is ideal for applications where requirements change frequently, allowing businesses to use only the energy necessary to meet their specific needs.
How a VSD Air Compressor Works
A VSD air compressor adjusts the motor speed using an inverter to meet actual air demand. Unlike a traditional fixed speed air compressor, which runs continuously at full speed, a VSD compressor adapts its motor speed based on the need for compressed air. For example, Atlas Copco VSD models incorporate patented Neos drive technology, offering superior control and reliability. This ensures that compressed air production matches the fluctuating demand, reducing energy waste.
The inverter controls the compressor’s motor speed to reflect real-time air requirements, making VSD compressors ideal for applications where air demand fluctuates. Many VSD systems use rotary screw air compressors, which operate smoothly and efficiently. Rotary screw VSD compressors maintain optimal lubrication and cooling, even at variable speeds, ensuring consistent performance. By eliminating the constant speed operation of fixed speed compressors, VSD compressors minimise idling and blow-off losses, significantly cutting energy costs.
In short, VSD compressors optimise compressed air production, adjusting motor speed to match demand, providing substantial energy savings compared to fixed speed compressors.
Variable Speed Drive Compressed Air Vs Fixed Speed Compressors
Making a decision about whether to invest in a variable speed air compressor or a fixed speed air compressor requires you to have a clear understanding of each model and what is different about them.
Unlike variable speed compressors, the motor speed of a fixed speed air compressor has to remain at full speed during each operation, no matter what your compressed air needs are, which can prove to be a costly decision. Fixed-speed compressors are best suited for applications with steady air demand, such as certain manufacturing processes. More and more businesses need compressed air systems that can meet their variable speed drive needs.
Pros and Cons of Variable Speed Drive Air Compressor
A variable speed compressor offers a wide range of benefits compared to a fixed speed compressor, including:
PRO 1: Keeping Your Business Energy Efficient
The VSD compressor is only ever running in the way that you need. This efficiency can result in up to 50% energy savings compared to fixed-speed models. This ability to reduce energy costs can help you to cover the price of the variable speed air compressor, often much quicker than you think.
PRO 2: Stopping the Need to Unload
As VSD air compressors can be started or stopped at the point of full system pressure, you are able to avoid the need to unload which will reduce energy cost and power consumption as well as allow you to save time. This is particularly useful in applications with frequent stop-start cycles.
PRO 3: VSD Air Compressors Mean No Idling Time
Unlike a fixed speed compressor, VSD air compressors sell themselves on being able to meet your compressed air demands in the way you need. This eliminates the inefficiencies and wear associated with idling, extending the lifespan of critical components. This means that variable speed drive technology requires no idling time, offering efficient controls when you need them the most.
PRO 4: Zero Blow-Off Loss with Variable Speed Compressors
When you have fixed speed compressors, you will find that your system needs to blow off air to function in the way you need. This type of blow-off will no doubt increase your energy bill. A VSD compressor adjusts seamlessly, ensuring minimal waste and optimal performance under varying loads. A VSD compressor makes sense in this situation as it can minimise sudden spikes and ensure that your flow demand increases and decreases as you need it with no blow-off needs.
PRO 5: No Need To Worry About Power Company Penalties
Fixed speed air compressors run the risk of peaking at high levels of amperage, resulting in penalties from power companies that increase costs. VSD air compressors mitigate these risks by maintaining consistent energy consumption and avoiding demand charges, as demonstrated in advanced models like Atlas Copco’s GA VSD+ series. As VSD air compressors have variable motor speeds, they are able to avoid these peaks and the frustrating penalties that come with them.
PRO 6: Variable Speed Air Compressors Offer Consistent Air Pressure
VSD compressors reduce pressure drops and enhance overall system efficiency by maintaining pressure within optimal ranges. The great thing about the VSD compressor compared to the fixed speed compressor is that the consistent pressure can be run much lower and allows you to increase your energy savings while getting the best results.
CON 1: The Upfront Investment: VSDs and Their Price Tag
However, innovations in VSD technology, such as integrated energy recovery systems, can accelerate the return on investment by further reducing operational costs. The upfront investment is an important factor in your purchasing decision, considering the potential return on investment over the compressor’s lifespan.
CON 2: VSDs: Not Ideal for Every Scenario
For such applications, fixed-speed compressors or hybrid systems combining both technologies may be more appropriate. Additionally, if your air demand falls below 40% or exceeds 80% of the compressor’s capacity for extended periods, VSD efficiency may decrease.
CON 3: When the Environment Matters: VSD Sensitivities
VSD compressors contain sophisticated electronics, which can make them more sensitive to extreme temperatures, dust, or moisture compared to fixed-speed units. Proper ventilation, filtration, and climate-controlled environments can help ensure optimal performance and longevity for VSD compressors. Ensure your installation environment is suitable for reliable VSD operation or consider additional protective measures if necessary.
How a VSD Compressor Can Save You Energy & Money
A VSD air compressor reduces energy use by adjusting the motor’s speed to match the actual compressed air demand, unlike fixed speed air compressors that run continuously at full speed. This adaptability makes VSD compressors up to 35%–50% more energy efficient, as validated by independent energy audits. This can result in up to 50% energy savings, significantly lowering electricity bills and reducing your carbon footprint.
By avoiding the energy spikes caused by fixed speed compressors, VSD systems eliminate peak demand charges. They also minimise wear and tear, extending the compressor’s lifespan and reducing maintenance costs. Whether you are using a rotary screw air compressor or another type, VSD compressors are designed to adapt to fluctuating air demand, offering a more efficient compressed air production process.
Additionally, models with energy recovery features can capture and repurpose waste heat, further reducing overall operating costs. With potential government incentives like rebates or tax credits, the long-term financial benefits of using a VSD compressor can outweigh the initial investment, making it a smart choice for energy-conscious businesses.
Is a VSD Industrial Air Compressor Right for Me?
If you are excited about VSD technology energy savings and enjoying the compressor’s motor speed you may be wondering if it is the right choice for you.
A VSD compressor is potentially right for you if:
- Your need for compressed air fluctuates
- You want to use it with rotary screw compressors
- You need to vary your compressor’s operating speed
- You don’t need large amounts of air on a consistent basis
- You need something energy efficient
- Your goal is to reduce operational costs and improve energy efficiency
VSD Air Compressor
However, a VSD air compressor may not be the right choice if:
- You have a consistent air demand on a daily basis
- If your air demand is constant within 5% – 10% of your air delivery flow rate
- You operate in environments unsuitable for advanced electronics without proper safeguards.
If you aren’t sure which type is best for your needs then it is worth completing a professional air audit from a specialist company. Comprehensive audits can also identify opportunities for additional system optimisation, such as leak detection or pressure management. The result of this audit will allow you to see if a VSD is the right choice.
Got questions about inlet valves, multiple shifts, reducing costs or anything else related to VSD compressors?
Get in touch with the Control Gear team to find out more.
FAQ
How does a VSD compressor adjust its motor speed to match actual air demand?
A VSD compressor uses an inverter to adjust its motor speed to match the actual compressed air demand. The inverter provides precise control over the motor’s operating speed, ensuring that the compressor only produces the amount of compressed air required at any given time. This prevents the system from running at a constant speed, saving energy and reducing wear on the equipment compared to traditional fixed speed air compressors.
What are the benefits of using a VSD compressor compared to a fixed speed compressor?
VSD compressors offer several benefits compared to fixed speed compressors, including significant energy savings, as they adjust the motor speed to meet the air demand. Unlike fixed speed compressors, which operate at full capacity regardless of need, VSD compressors adapt their speed in response to fluctuating demand, leading to reduced energy consumption, fewer peak demand charges, and less wear on the equipment. This makes VSD compressors ideal for applications with varying air requirements.
Is an air audit necessary before implementing a VSD compressor?
Yes. Conducting an air audit is highly recommended before implementing a VSD compressor. An air audit helps identify the actual air demand and patterns of use, ensuring the VSD compressor’s motor speed is optimised for your specific requirements. This audit can help determine if a VSD system is the most appropriate solution for your compressed air needs and can further enhance energy savings by tailoring the system to match demand fluctuations.
FAQ
How does a VSD compressor adjust its motor speed to match actual air demand?
A VSD compressor uses an inverter to adjust its motor speed to match the actual compressed air demand. The inverter provides precise control over the motor’s operating speed, ensuring that the compressor only produces the amount of compressed air required at any given time. This prevents the system from running at a constant speed, saving energy and reducing wear on the equipment compared to traditional fixed speed air compressors.
What are the benefits of using a VSD compressor compared to a fixed speed compressor?
VSD compressors offer several benefits compared to fixed speed compressors, including significant energy savings, as they adjust the motor speed to meet the air demand. Unlike fixed speed compressors, which operate at full capacity regardless of need, VSD compressors adapt their speed in response to fluctuating demand, leading to reduced energy consumption, fewer peak demand charges, and less wear on the equipment. This makes VSD compressors ideal for applications with varying air requirements.
Is an air audit necessary before implementing a VSD compressor?
Yes. Conducting an air audit is highly recommended before implementing a VSD compressor. An air audit helps identify the actual air demand and patterns of use, ensuring the VSD compressor’s motor speed is optimised for your specific requirements. This audit can help determine if a VSD system is the most appropriate solution for your compressed air needs and can further enhance energy savings by tailoring the system to match demand fluctuations.