Will a variable speed air compressor save me money?

Will a variable speed air compressor save me money? The short answer is possibly but it all depends on a number of factors.

There are two main types of industrial rotary screw compressors available on the market.

Fixed Speed
VSD (stands for variable speed drive.)

Which compressor is better for you in terms of energy efficiency? Air4u Group offers both VSD and fixed speed compressors, because each type offers advantages in specific circumstances.

Fixed speed compressors

Traditional air compressors are fixed speed, meaning they run at a constant and consistent speed. This produces a fixed amount of compressed air per minute. If your application requires a constant speed at all times, then a fixed-speed compressor will often get the job done. Once you switch it on, it eithers producing 100% of its capacity, or none. When air is required, it runs at full capacity, when demand for compressed air drops, it stops making compressed air altogether although the motor keeps on running.

This means that it is either using maximum energy to create compressed air, or slightly less than half of the energy to keep the motor running when it is not making compressed air. For instance, an 11 kW compressor will use 11 kW of energy when running at full capacity (known as ‘on load’) and approximately 4.5 kW of energy when running at no capacity (known as ‘off load’).

Therefore, a fixed speed compressor is energy efficient when it is supplying compressed air for a demand that is constant and matched closely to the maximum capacity of the compressor. Running this kind of compressor when demand is low results in wasted energy because the motor is using energy but there is no compressed air being made.

VSD compressors

A VSD compressor uses inverter technology that automatically adjusts the compressor’s motor speed to the compressed air demand in real-time. In other words, it only gives you as much compressed air as you need at any given time. That doesn’t make a lot of difference if you need the same amount of compressed air all the time. If, however, your compressed air demand fluctuates, then you can achieve major energy savings with this environmental technology, a variable speed drive.

A VSD compressor is a smart choice when demand for air varies by process, time of day, shift or time of the year. When demand fluctuates, a VSD compressor that varies its speed is much more energy efficient than a fixed-speed compressor that can only run flat out.

How do I know whether my compressed air demand fluctuates, or is relatively static? And would a VSD compressor save me money?

A detailed analysis can be carried out by installation of a data logger on the compressor. This monitors and records the energy used by the compressor over a period, for instance a week. The information is downloaded and presented in a report which provides a compressed air demand profile detailing the energy costs. Air4u Group are able to provide this service. For more information, please see our website https://www.air4ultd.co.uk/why-have-compressor-data-logging/

Other key factors to consider before upgrading your compressor:

Ensure the compressor you are considering is adequately sized – not too small but not too big either. You will want to consider the possibility of future growth so sometimes considering a compressor slightly bigger is a good idea. For more information, please see our website https://www.air4ultd.co.uk/how-do-i-know-what-size-compressor-i-need/

Ensure you have minimum compressed air leakage in your pipework. Leaks are the single most costly issue in a compressed air system. Money is literally disappearing into thin air in wasted energy, compressor running costs, service costs and wear and tear. Oure website has suggestions on how to find and fix a leak https://www.air4ultd.co.uk/find-and-fix-that-leak/

There are many makes of compressors on the market, however it’s worth investing into a quality product so that you only buy once.

Air4U Group pride ourselves on offering compressors that are extremely energy efficient and with a reputation for reliability and robust construction.

By investing a little extra in a more energy efficient and reliable compressor, you can save a significant amount of money in electrical running costs and reduced down time.

If you agree to a service plan with us for your new compressor, most quality compressor manufacturers will offer you an extended warranty and we can offer fixed price servicing for the length of the warranty. This means you can budget how much the maintenance will cost for the life of the service plan.