How do I know what size compressor I need?
You are looking for a new Compressor and you know that compressed air can be a major contributor to your energy bills. But how do you know what size compressor is right for your application?
For this, it helps to understand the measurements of flow and pressure, and how they affect performance of an air compressor. As with any industrial purchase, it is best to seek out expert advice from a Compressed Air Specialist, such as Air4u Group, but here is our handy guide to give you an overview.
Pressure and capacity are the two main specifications to look for when buying an Air Compressor. Pressure means 'how strong' and capacity means 'how much'.
Why is it important to buy an Air Compressor with the correct Flow and Pressure.
Known as the fourth utility, compressed air can be a major contributor to your monthly energy bills, accounting for as much as 30% of your electrical power consumption. Therefore, you need to think carefully and get advice when you are making a new purchase or signing a new hire agreement.
Over-specification can mean spending more on capital equipment than you need to. So beware of the sales person who tried to push you into purchasing a bigger, more powerful machine than your application requires. At the same time, going for a cheap Air Compressor can lead to under-specification, with the result that it does not meet your needs and you end up having to replace it a short time later.
As well as cost benefits, purchasing the right Air Compressor will reduce downtime, increase productivity, lower your energy bills, and reduce lifecycle costs.
How do I choose the right size of Compressor for my application.
The temptation when replacing an old air compressor is to look at the kilowatt (kW) rating and buy 'like for like'. A better approach would be to work out the PSI and CFM - the pressure and flow - required for your application and select your model accordingly.
Choosing a machine with a high CFM does not automatically mean you are buying a better air compressor. The higher the CFM, the more powerful the compressor. But you may be paying for power you do not need, leading to higher energy bills. For example, a compressor with a small CFM will be sufficient for power air tools, but to operate the pneumatics in a manufacturing unit, you will need a Compressor that can pump out a significantly higher air flow.
Another variable is whether you are running or planning to buy a Variable Speed Compressor, such as those in the Atlas Copco VSD and VSD+ range. These can offer significant energy and cost savings, compared with traditional Fixed Speed Compressors.
Book a Data Logging Audit/Energy Audit of your system.
As previously mentioned, a Data Logging or Energy audit will help you establish what size compressor you need and the levels of CFM and PSI. These audits are usually carried out as a free service and consist of Data Logging your existing compressor and equipment. This gives accurate feedback on your compressed air demand, pressure and cycle over a set period of time. This identifies energy costs and where savings can be made. Data like this is crucial to help answer the question of what size compressor you need.
For more information on Data Logging, check out our blog on this subject https://www.air4ultd.co.uk/why-have-compressor-data-logging/
What else should I consider when buying a new Air Compressor?
Because the latest Air Compressors on the market make use of state-of-the-art technology and operate more efficiently, you may find that you need a machine with a lower kW output than your older model.
Also, there are many elements to a Compressed Air System, such as dryer, filters and pipework, along with pneumatics. Some of these may need upgrading to get the best results from your new Air Compressor.
Finally, do not forget to factor in any projected increase in use to future proof your purchase. For example, if you are planning to open a new manufacturing line or increase your production schedule to 24/7.
Keep a look our for our future blogs on Pressure and Flow/Capacity for more information.