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
| Construction | Axial fans in weatherproof cowls, or supply and exhaust units with filters as the air quality requires |
| 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. |
A packaged unit with fan, filters, cooling or heating coil and mixing box that conditions and delivers supply air. Pre, fine and HEPA filters as the air quality requires. Client-stated blade types for the AHU in general: Backward curved and forward curved.
Industries
Other fans in data centres and equipment rooms
AHU in other processes
Pharmaceutical Clean RoomsFood and Dairy Spray DryersAutomotive Paint ShopsNuclear Facility VentilationHospitals and LaboratoriesSpinning MillsPharmaceutical Coating and Granulation
Information needed to select or quote
- Gas volume and temperature. Actual flow at the inlet, normal and upset temperature, moisture.
- Dust or pollutant. Inlet loading, particle size distribution, whether it is abrasive, sticky, hygroscopic or combustible; for gases, the species and concentration.
- Required outlet. The emission limit or clean gas concentration the unit must meet.
- Site. Available space and height, material of construction preferences, and how the collected material is to be discharged.