Anyone who has ever visited a modern factory or their local mechanic's shop knows that pneumatic tools and the air compressors that drive them are not known as being very quiet machines.
Indeed, most compressors and pneumatic tools that operate at higher levels of power are well known as being extremely loud.
Nevertheless, there are many cases where compressed air is needed, but obnoxious amounts of noise are inappropriate.
Examples might include professional offices (like your dentist's office), small workshops (in shared space), or at home (especially if you live in an apartment or attached home).
As a consequence, an entire subset of compressor manufacturers has opted to focus on the creation or the silent air compressor.
These units are specifically designed to operate quietly, with as little noise as is possible.
This is accomplished in a number of various ways depending on the manufacturer in question.
Further, most of the silent compressor technology is proprietary, so they specifically do not advertise exactly how they manage to accomplish this goal.
Nevertheless, the fact remains that today one can find extremely quiet compressors though to date there is no such thing as the truly silent air compressor that makes no noise whatsoever.
When looking for a silent air compressor, there are a number of attributes you can take into account.
The first is how the compressor is powered.
As a general rule, most applications where volume is a factor tend to require smaller power levels; which means smaller overall compressors.
Similarly, most applications requiring silence are also for stationary compressors.
That is, they are installed in the office or workspace and then left along.
As a consequence, virtually all silent air compressors operate with electric motors and are designed to be plugged into a regular power outlet.
The specific mechanics of the air compressor also have a direct bearing on the level of noise created by them.
By far the most silent air compressor type is scroll compressors; not only are the quiet, but they are also very efficient and reliable at low volumes.
However, the technology is not widespread and generally speaking one should expect to pay a premium price for one.
The next most silent type of compressors are rotary vane compressors, but these tend to be large industrial units that may be too large for many applications where sound is an issue.
The most common silent compressor type is the piston compressor.
This is old technology that has been well developed for over a century, so piston compressors can be found in all shapes and sizes and they generate considerably less noise.
Many of the specialized compressors that are designed specifically with noise in mind also feature other advanced options.
For example, many of them use various types of insulators, dampeners, and other anti-vibration technology.
The last couple of decades have also seen the introduction of a wide range of technically advanced modern materials being used to create air compressors that make less noise.
By far the most silent air compressors that you will find on the market combine a number of these different technologies and innovations to create very silent running machines.