Power consumption
The maximum power consumed by the fan during operation. The higher the power consumption, the higher, usually, the greater the airflow rate created by the fan, and, accordingly, the higher the performance of the device. On the other hand, power usually directly affects the price, all other things being equal.
Maximum noise level
The maximum noise level produced by the fan when operating at the highest speed. For comparison: a noise of 30 dB corresponds to a distinguishable whisper at a distance of 5 m, 40 dB — to human speech, and 50 dB — to the sound background in an office room. The quieter the fan runs, the more comfortable it is to use.
Diameter
The item refers to axial fans and gives an idea of the size of the device. The larger the size, the more airflow the fan can produce at lower RPM (and therefore less noise). It is worth noting that sometimes this indicator is indicated for the blades, and sometimes it is fully indicated for the entire grill body. However, this already gives an idea about the size and capabilities of the device.
Number of blades
With the same power and blade width, fans with numerous blades can boast of greater air mass distillation performance. However, the formation of a powerful airflow is not affected by the number of blades, but by their
diameter. In addition, the operation of multi-bladed fans is usually associated with an increased level of noise.
Metal structure
Fans on a metal chassis are distinguished by a reliable and high-strength design. They stand steadily on different types of surfaces, have an exquisite appearance, but are heavier than their counterparts with plastic cases. Often such fans are equipped with a guard grills and blades also made of metal.