The process
Equipment rooms need large volumes of filtered, cooled air at low noise with redundant fans. The fan is selected against filter and coil resistance with the motor outside the airstream where possible.
The gas at the fan
Filtered, conditioned supply air through pre, fine and HEPA filters. The fan is selected against the filter pressure drop as it loads, at low noise.
Selection for this duty
| Blade form | Backward curved or aerofoil for the best efficiency on clean gas |
| Material of construction | Mild steel |
| Drive and bearings | Direct coupled or belt driven; belt drive where the duty point may need tuning at site |
| Density at the fan | At about 22°C the gas density is close to 1.20 kg/m³, 99% of standard air. Pressure developed and power drawn fall in the same ratio, so the selection is made at this density and the motor is checked at cold start. |
Moves air through a plant or building for fresh air supply, heat removal and fume dilution where the system is ducted. Low pressure, long hours, so efficiency and noise set the selection. Client-stated blade types for the Ventilation Fan in general: Backward inclined and forward curved.
Industries
Other fans in data centres and equipment rooms
Ventilation Fan in other processes
Services on this fan
Information needed to select or quote
- Duty point. Volume flow and static pressure at the fan inlet, with the gas density and temperature or the conditions to derive it.
- Operating conditions. Site altitude, normal operating temperature and continuous or intermittent duty.
- Gas stream. Dust loading and particle size, corrosive species, moisture, upset temperature and any tendency of the material to deposit on the impeller.
- Mechanical. Rotation viewed from the drive end, discharge orientation and motor power.
