Power
The power of the engine installed in the compressor. It is not the main parameter in evaluating the efficiency of the device — here the performance and nominal pressure play a decisive role (see above), and the engine is selected in such a way that its power is sufficient to ensure the claimed characteristics. However, this indicator still has practical significance: in compressors with an electric motor (and there are now most of them; see “Engine type”), the engine power determines the total energy consumption of the device, as well as the requirements for the network where it is planned to connect it (for more details, see “Voltage networks"). In addition, the power of the engine (regardless of its type) must be known in order to calculate the optimal performance value using some special formulas.
For internal combustion engines, power is traditionally expressed in horsepower (hp); you can convert it to watts in this way: 1 hp. = 735 W.
Rotation speed
The speed of rotation of the compressor motor shaft in normal operation. This parameter, usually, does not affect the efficiency of the unit — the main indicators are still the performance and nominal pressure (see above). At the same time, it allows you to evaluate the design features of the compressor and its durability. The fact is that a higher rotation speed allows the use of fairly simple and inexpensive working mechanisms, but it increases the wear of moving parts and reduces the motor resource. Therefore, a model with a lower number of revolutions is likely to cost more than the "high-speed" version, but it will also last longer (ceteris paribus characteristics — performance, pressure, drive type, design; see all above).
