Variable Speed Compressors: Everything you need to know on how to save on energy costs within your industry

Imagine being inside a vehicle where power was always delivered as 100% or 0%. Regardless of how much power was required at the time, the vehicle always drives as fast as possible.

When traffic lights turn red, the vehicle suddenly stops. And when they turn green, the vehicle returns to full power.

You could imagine the questions you would raise from this: How much fuel is the car wasting? Why is it always going at 100%, regardless of how much is required? Is this good in the long term for the engine?

Although simplified, this logic can be applied to many things such as fans, machine tools, conveyor belts, and even your air compressors.

This is where Variable Speed Drive Air Compressors find a purpose. Variable Speed Compressors can help to increase efficiency, reduce energy costs, improve performance and extend the life cycle of the air compressor.

However, some people may still be unfamiliar with the technology despite their advantages. Therefore, we have taken a deep dive into Variable Speed compressors, including the mechanics behind their operation, through to their place alongside fixed-speed air compressors.

What is a Variable Speed Compressor? And how does it work?

Exactly as the name suggests, Variable Speed Compressors are Air Compressors that can adjust the output based on what is required at that time. Rather than operating at a fixed speed regardless of changes in demand, Variable Speed Compressors are fitted with a Variable Speed Drive (sometimes shortened to VSD) that allows for changes in the system to be accounted for. This special drive controls the speed of the compressor, which is what allows these units to become more efficient and reduce energy costs when compared to their fixed-speed equivalents.

What are the main benefits of a Variable Speed Compressor?

There are many benefits to implementing these systems into your operation, however, we have picked out the top 5 reasons why you should consider adding a variable-speed compressor:

More efficient: Estimates taken from Industry show that on average Variable Speed Compressors can save up to 30% on energy usage by varying compressor performance in line with system demand.
System Longevity: A variable speed compressor is designed to optimise the performance and motor speed. This can reduce strain on electrical and mechanical parts of the compressor, allowing for an increased system life span and minimised downtime.
System Control: Variable speed compressors allow for greater control over pressure throughout the system. The motor speeds can be slowed down, stopped completely, or increase the RPM depending on the requirements at the time.
Reduced Costs: Variable speed Compressors are more efficient with their energy usage and power delivery. They can adapt their output to suit the demand required at that time, whether this is a change of shift, seasonal change, or week vs weekend change. This reduces the costs spent on energy.
Life Cycle: Because Variable Speed Compressors operate at lower speeds, their energy costs throughout the life cycle are reduced. This means there is less strain on critical parts, which further extends the life cycle savings as they can inherently run for longer.

A potential variance in average volume flow due to changes in weekend usage

How Reliable are Variable Speed Compressors?

Like most modern air compressors, Variable Speed Compressors are highly reliable, especially in scenarios where demand changes frequently. However, like all systems, routine maintenance using genuine parts and coolant, servicing by qualified engineers, and correct installation are as important as the compressor itself. This is even more important as much of the technology that allows variance in speed in the compressor is highly sensitive.

To ensure the best quality of performance from the compressor, speaking to compressor experts such as Scot Industrial Air will ensure all maintenance and servicing requirements are fulfilled to the highest standard, from our variety of locations available.

Variable Speed Compressor vs Fixed Speed Compressor: Is it one or the other?

In short, it depends on your overall requirements. Variable-speed compressors come with a large set of benefits, however, Fixed speed compressors are ideal for scenarios where power is required continuously at 100% and demand fluctuates very little.

The advantages of both types mean that the most efficient solution for your needs could be a system that combines one or more of each type. This means your system can still adapt to changes in demand but provide sufficient peak power when required. It also spreads out system redundancy between multiple compressors, rather than servicing or repairs significantly decreasing operational capacity.

For a more technical display of how fixed speed and variable speed compressors can be synchronised to work together, this short explainer video can help to understand how useful they can be:

Are Variable Speed Compressors worth it?

Variable-speed compressors can greatly increase the efficiency of your system. Their greatest advantage is energy saving by adapting to demand, which makes them ideal for businesses that are investing in their energy efficiency. This not only helps reduce expenditure on energy costs but also helps organisations to meet sustainability goals.

Their initial upfront investment is normally greater when compared to fixed-speed compressors, however, if installed where appropriate, they can return the difference in investment by energy costs saved over time. This is especially important for operations where the compressor will likely work for many years.

To find out if a variable-speed compressor is the correct choice for you, understanding your requirements is critical. Our specialist engineers at Scot Industrial Air recommend an Air Audit to fully understand your system demands and highlight potential areas of improvement. With nearly 40 years of experience and true 24/7 servicing, we can provide expert advice and recommendations for your system.

Speak to one of our friendly team today by calling 0141 556 7301 or contact us online using the form below