This article's table of contents introduction:
- Scenario 1: You truly mean 7000 CFH (± 117 CFM)
- Scenario 2: You actually mean 7000 CFM
- To get a proper quote or specification, you must provide:
- Quick Sizing Rule (Centrifugal Fan)
- Example Manufacturer Sizing (7000 CFM)
There is not a single "7000 CFH centrifugal fan." CFH stands for Cubic Feet per Hour, which is unusual for fans. Fans are almost always rated in CFM (Cubic Feet per Minute) .
7000 CFH is equivalent to 7 CFM (since 7000 ÷ 60 = 116.7).
Let's look at both possibilities, as you likely mean one of these two scenarios:
Scenario 1: You truly mean 7000 CFH (± 117 CFM)
This is a very small air volume. A centrifugal fan at this airflow is likely a small blower wheel used for:
- Boiler inducer fans (exhausting combustion gases)
- Laboratory exhaust (fume hoods with small ductwork)
- Electronics cooling (rack-mounted blowers)
- Small dust collection (single machine pickup)
General Specs at 117 CFM:
- Motor: 1/15 HP to 1/4 HP (typically 115V or 230V single phase)
- Inlet/Outlet: 2" to 4" diameter
- Static Pressure: Up to 1"-3" w.g. (high pressure, low volume)
- Sound Level: Relatively quiet (40-55 dB)
Key features of a centrifugal fan at this size:
- Forward curved blades (for quiet, low speed operation) or backward inclined (for higher efficiency).
- Often a direct drive configuration.
Scenario 2: You actually mean 7000 CFM
This is a very large industrial centrifugal fan.
General Specs at 7000 CFM:
- Motor: 5 HP to 15 HP (3-phase, 208V-575V)
- Inlet/Outlet: 10" to 16" duct diameter
- Static Pressure: 2" to 10" w.g. (depends on ductwork resistance)
- Sound Level: Very loud (80-95 dB) - needs ear protection
- Weight: 150-400 lbs or more
Common applications:
- Large HVAC air handlers
- Industrial dust collection (baghouses, cyclones)
- Paint spray booths
- Mining or tunnel ventilation
- Kiln exhaust
To get a proper quote or specification, you must provide:
| Parameter | Your Value |
|---|---|
| Airflow | 7000 CFH (117 CFM) or 7000 CFM ? |
| Static Pressure | _____ inches w.g. |
| Duct Size / Inlet | _____ inches |
| Voltage / Phase | _____ V, Single or 3-phase |
| Application | (e.g., dust, fumes, clean air, hot air) |
| Mounting | (inline, roof, wall, floor) |
Quick Sizing Rule (Centrifugal Fan)
- Low pressure (0-2" w.g.): Forward curved blades (quiet, lower cost)
- Medium pressure (2-6" w.g.): Backward inclined blades (more efficient)
- High pressure (6"+ w.g.): Airfoil or radial blades (rugged, industrial)
Example Manufacturer Sizing (7000 CFM)
For a 7000 CFM centrifugal fan at 4" static pressure:
- Fan Size: 15" wheel diameter (approx.)
- Motor: 10 HP, 1800 RPM
- Drive: Belt drive (allows speed adjustment)
- Typical Model: Greenheck BIDW-15, Twin City VCB-15, New York Blower 15GI
Please clarify: Do you need 7000 CFH (small blower, 117 CFM) or 7000 CFM (large industrial fan)?
