Industrial Ventilation Fan Chart
Helpful information from the ICAN Information Center: comparing the features of fans used in various types of industrial ventilation systems.
| Centrifugal | Axial | |||||
|---|---|---|---|---|---|---|
| Radial Blade | Forward Curved | Backward Type | Tube | |||
| Backward Inclined (BI) | Backward Curved (BC) | Backward Airfoil (BA) | ||||
| Equipment Cost | $$$ | $$ | $$$ | $$$$ | $$$$$ | $$ |
| Efficiency | <50% | 40-50% | 50-70% | 60-70% | 60-80% | <50% |
| Noise Level | High | Medium | Low | Low | Very Low | Very High |
| Susceptibility to Imbalance* | Very Low | High | Medium | Medium | Medium | High |
| Abrasion Resistance* | High | Low | Medium | Medium | Low | Medium |
| Non-Overloading?* | No | No | Yes | Yes | Yes | No |
| Typical Pressure Ranges WC | 10-30 | 0-3 | 3-30 | 0-0.5 | ||
| Typical Flow Ranges CFM | 500-5000 | 3000-20,000 | 2000-50,000 | 2000-30,000 | ||
| Cost of Operation (per CFM) | $$$$ | $$$$ | $$$ | $$$ | $$ | $$$$ |
| Common Uses for Industrial Ventilation |
Low Flow / High Pressure Example:Cyclone Inlet Fans |
High Flow / Low Pressure Examples:HVAC; Ambient Air Cleaners |
Medium to High Flow / High to Medium Pressure Examples:Central Ducted Systems; Cartridge Dust Collectors; Mist Collectors; Wet Dust Collectors; Bag Collectors |
Very Low Pressure Examples:Roof Exhausters; Kitchen Fans; Paint Booths |
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*Notes:
Susceptibility to Imbalance. When do fans become imbalanced, and why does it matter? Imbalance can occur when there is any kind of sticky material even in fairly clean air streams. The sticky material will stick to the fan blades and can cause the fan to become imbalanced. The result is that bearings can be damaged, mounting plates cracked, and bolts loosened, and the fan becomes very noisy. In addition, if the shaking collector is connected to precision manufacturing equipment, the equipment itself may begin to operate out of tolerance.
Abrasion Resistance. When and why does it matter? Whether a fan is abrasion resistant doesn't matter in a dust collector on the clean side, but if the fan is ever located on the dirty side, such as on the inlet of cyclone dust collectors, even small abrasive particles will wear fans out. So for material handling, radial blade fans are generally used because they have the highest abrasion resistance.
Overloading / Non-Overloading. When can fans overload the motor? Fans will tend to overload the motor when air cleaners do not have normal or expected restrictions in the airflow, except for backward inclined fans that do not overload whether the air flow is restricted or not. Air cleaners that have forward curved fans can actually fail if the air cleaner is operated without a filter, or while the cabinet is open, or when disconnected from its ducting. Thus fans that are overloading have to be carefully sized for the pressure range in which the air cleaner operates, or, on the one hand, the motor may be susceptible to becoming overloaded and failing, or, on the other hand, the motor may be oversized and use far more energy than necessary. Non-overloading, backward type fans, on the other hand, provide reliable performance over a broad range of pressures and flows.