Air compressors, and the pneumatic tools driven by them, are well known for being loud and obnoxious machines; from the machine at your local garage to the one you use to top up your tire pressure. However, there are many instances when air compression is needed, but loud and obnoxious noise is not. For example, air compressors for use in professional offices, in small attached workshops, or at home may need to be much quieter than the one at your mechanic’s shop. Not surprisingly, this means there are many different air compressor types designed specifically to reduce the noise. In general, there are specific characteristics you can look for when searching for a quiet air compressor.
One of the first things to look at is how the air compressor is powered. Although there are a lot of different types of engines and motors available, if volume is a primary concern you can automatically rule out any air compressor powered by anything other than an electric motor. Quite simply, there is no quieter power option on the market today when it comes to air compressors. Although this narrows the field down some, electricity remains the most popular power source for air compressors on the market, so the field is still very wide open.
One popular notion frequently suggested by experts when asked for advice about quieter air compressors is that you should look for one that uses an oil/air mixture as opposed to an oil-free type of compressor. Generally this is valid advice; compressors that use oil do usually run considerably quieter than similarly sized machines that are oil-free. The real problem here is whether or not oil/air is acceptable for your application. Although the technology is improving, there is no oil/air separator unit available that can completely remove all of the oil from the expelled air, so the question to be asked is: does it matter if there are small traces of oil in my compressed air? If the answer to this question is “no”, then a compressor using a oil/air mixture will probably be quieter than the alternative. If the answer is “yes”, then the volume does not matter as the oil-based system is not meet your requirements.
Another important consideration is the way that the air compressor works. There are many different types of air compressor mechanisms, and some make considerably less noise than others. Many of the more popular models billed as “quiet” use piston technology as opposed to the more popular rotary screw technology to compress the air, as this method tends to be quieter. Rotary vane technology is even quieter than piston technology, but rotary vane compressors tend to be larger so may not be appropriate for a small office or other setting with limited space available. Finally there are scroll compressors, which are very quiet, efficient, and reliable at low volume levels. However, expect to pay more for the scroll compressors as the technology is very good, but not as common.
You should also bear in mind that there are also a number of companies that focus exclusively on the quiet air compressor. These companies use a number of techniques – such as using special anti-vibration technology or alternative materials – to reduce the overall sound created by the compressor. These units do work – and work well – but you should expect to pay a premium for them.