When buying a new air compressor, to select the right air compressor is vital to ensure you keep your energy and maintenance costs to a minimum and to deliver long term operating cost savings. Selecting the wrong compressor for your application can lead to thousands of dollars wasted in inefficiencies.

There are a number of things to consider to ensure you get the right air compressor for you, 10 important considerations include:

1) What are you using compressed air for?

How you are going to use the compressed air will dictate the best type of air compressor for your application. Gaining a thorough understanding of your usage by determining how much air you need and when you use it will guide you to the type of air compressor best suited to deliver it efficiently. For existing systems a thorough air audit will help you identify an exact usage profile which can then be used to make informed decisions on requirements.

2) Where are you going to locate the compressor?

Make sure you consider where you will locate the air compressor, if it’s outside shelter and weatherproofing will need to be considered, if inside ventilation and size & configuration will need to be considered. The key to a successful installation is sufficient access for maintenance.

3) How much pressure do you need?

Calculating the minimum pressure you require is vital in terms of maximising efficiency. Every increase of 50 kPag (0.5 bar) in operating pressure results in additional energy consumption of 4%. When applied to a 200 kW compressor an increase of 140 kPag (1.4 bar) in operating pressure results in an increase of over 20 kW in energy consumption, long term that equates to some serious money.

4) How much Free Air Delivery (FAD) do you need?

FAD refers to the maximum amount of air the compressor can produce, measured at inlet conditions. Ensure when selecting a compressor, that the air flow figure quoted is measured in terms of FAD to ensure you are getting an accurate figure of how much air flow the compressor will produce. Some manufacturers may quote figures from the internal parts of the compressor, also ensure the capacity is based on the operating pressure you will work at.

5) How many kilowatts do I need?

Look for a compressor with the highest FAD for the same amount of input power. This means it is a more efficient compressor. The lower the kilowatts of the compressor that can produce the FAD you require will reduce your energy usage and reduce operating costs long term.

6) What size air receiver will I need?

Air receivers act as a buffer for a compressor against constantly cycling on and off load. The larger the air receiver the more compressed air storage, the more protection from cycling and the resulting excessive energy usage and wear and tear on the compressor. You are always better off having an over-sized air receiver than an undersized one.

7) What features should I look for?

There are numerous features depending on the size and type of compressor you are buying. Features like Variable Speed Drive (VSD) may save you more money on energy costs but aren’t suited to every application. The best features to look for with air compressors are the less moving parts the less it’s going to cost in maintenance, things like direct drive airends eliminate belts and gears therefore less parts that may need maintenance. Also look for features like cast iron construction, stainless steel control piping, efficient coolers etc. for efficient and reliable operation reducing long term operating costs.

8) Electrical requirements

It’s important to know what amperage is available at the premises the air compressor will be installed. Each size and type of compressor will have different power requirements so you need to ensure that you’re premises are adequately powered to start and operate the compressor.

9) What control system is best?

There are a number of different control systems available to configure and operate your compressed air system. As mentioned the best control method will also be determined by your usage profile. How much air and when you use it will dictate the most appropriate type of control to maximise efficiency and reliability. Popular control types include start/stop control, constant speed unloading, VSD, modulation and variable displacement.

10) What else is there to consider?

Other considerations should include what moisture removal do I require? As air compresses it produces moisture, that moisture can cause instrument/equipment damage or product spoilage if not removed before end use. You need to know what quality air you require and have the correct aftercooling, drying and filtration to achieve it.

These are some of the main considerations before selecting and installing an air compressor in your plant. The best way to ensure you select and install the right equipment is to speak to a compressed air expert who can advise you correctly.

For expert advice speak to Southern Cross Compressors on 1300 098 901 or simply complete the “Enquire Now’ form on this page.