20060 AC Powered Ventilation Fan

The design of the AC powered ventilation fan first needs to measure the relationship between its air volume and wind pressure,and it is very difficult to measure the characteristics of the air flow.At present,there are two common ways for wind tunnel testing and two-box method.

Air volume and static pressure characteristics are measured in a two-box way,using a variable exhaust system in a two-box way to extract air to adjust the air density,opening the nozzle in an instant will cause a sharp change in static pressure and air volume,and then just read the pressure data on each static pressure gauge.

Under standard atmospheric pressure and fixed operating voltage and frequency,static pressure is a function of air volume.The static efficiency of the AC powered ventilation fan is equal to the volume of the air volume multiplied by the static pressure divided by the input electrical energy.The AC powered ventilation fan consists of a motor, a fan blade and an outer frame,so its efficiency includes the motor efficiency of the motor,and the air flow efficiency of the fan blade and the outer frame.

The entire system impedance/System characteristic curve of the AC powered ventilation fan when the air is flowing,the air will encounter the obstruction of the internal parts of the system in its flow path,and the impedance will limit the free flow of air.The change in pressure is the measured static pressure,expressed in inches of water column.In order to confirm the cooling watts of each row,the system designer or manufacturer must not only have the effective fan characteristic curve of the AC powered ventilation fan to determine its maximum air volume,but also must know the change of the system wind resistance curve.The internal components of the system also affect the loss of wind pressure.This loss varies with the volume of air,known as the system impedance.