A lot of workshops and ‘less complicated’ compressed air systems owners often face a variation on which compressor option should we take?
The choice is between:
Installing a single big air compressor that can deal with the peak load of the system (as well as future increases in demand)?
Or
Installing two compressors that have the same total output as the larger one but will have a lower power demand while they are unloaded.
To be fair when you buy an air compressor you are guessing or modelling what you think your future demand for compressed air will be over the life of the compressor. Which is not an easy task. Think about the money the National Weather Service spends trying to forecast tomorrow to get it wrong…
There are other options too such as a Variable Speed Drive or modulating inlet air compressors… as well as system design features like storage tanks.
The Best Choice of Air Compressor Depends on Your Duty Cycle
Just in case – duty cycle is the amount of time it needs to be running at full capacity. The rest of the time it is running unloaded. So 60% duty cycle means your air compressor will run at full capacity 60% of the time and be unloaded the remaining 40%.
However it will turn on and off based on the demands of your compressed air appliances. So if you need a series of air tools to run 10 hours a day then the demand is fairly constant. However if you are using your compressed air to propel abrasives, the demand will spike while you’re blasting but the rest of the time your compressed air needs might be minimal.
Both scenarios could see a 60% duty cycle for a given air compressor… but you will find the dynamics of your duty cycle will influence your best choice.
As a rule when you have continuous demand you are better off taking the larger compressor that delivers the volume of air you need at the desired pressure.
However when faced with demand that spikes you might find that running two 25hp compressors instead of purchasing a single 50hp compressor will be more energy efficient. It means you’ll still be able to meet peak demand but you’ll consume less power while your compressors are idle or your compressed air consumption is low enough that a single compressor can fulfill the demand, then the second compressor can provide the additional air when it’s needed.
This sort of lateral thinking is necessary when you are looking to buy your next air compressor(s). Power consumption represents up to 75% of the total cost of ownership of an air compressor while the purchase price is usually 10-15%. It can make sense to invest a little extra up front to slash your power bills.
If you are looking for a collaborative approach to getting a more efficient compressed air system then contact the team at Pye-Barker on 404-363-6000 or drop us a line sales@pyebarker.com and we can help find the right compressor solution for your situation.
