Does High Altitude Affect Centrifugal Fans?

There are two main issues when centrifugal fans operate in high-altitude areas: one related to the fan itself, and the other related to the motor.

First, the fan itself.
As altitude increases, the air becomes thinner and the air density decreases. When the air density decreases, the fan’s pressure will drop, and the airflow will also decrease accordingly.
For example, at low altitudes the air density is about 1.2 kg/m³, while at high altitudes it may drop to around 0.9 kg/m³.

Second, the motor.
In high-altitude areas, the motor’s heat dissipation is not as effective, which makes it more prone to overheating. If the motor overheats, its output power will decrease.
For instance, a 200 kW motor may only deliver about 160 kW of actual working power.

In addition, because the air is thinner at high altitudes, the motor requires higher insulation standards. Otherwise, corona discharge may occur. If corona discharge happens, the motor may run unstably and its operation can become disordered.