Fan Velocity Calculator:
Enter the value of flow rate, CFM(ft3/min) and diameter, D(in) to determine the value of fan velocity, V(ft/min).
Fan Velocity Formula:
Fan Velocity refers to the speed at which air moves through a fan system and is a crucial aspect in designing and operating HVAC (Heating, Ventilating, and Air Conditioning) systems, ventilation systems, and various types of industrial exhaust systems.
It determines how effectively a fan can ventilate a space or cool equipment by influencing the volume of air it can move within a given time frame.
Understanding fan velocity is key to achieving optimal airflow and system efficiency, affecting everything from air quality to temperature control. It helps in sizing fans and ducts correctly to ensure that they meet the operational demands of residential, commercial, and industrial environments without overloading the system.
Fan velocity, V(ft/min) in feets per min is computed by taking the flow rate, CFM(ft3/min) in cubic metres per second dividing it by pi, the square of one twelfth of the diameter, D(in) in inches and four and then dividing this quotient by 60 to convert the measure from feet per hour to feet per minute.
Fan velocity, V(ft/m) = CFM(ft3/min) / (pi * (D(in)/12)2/4) / 60
V(ft/min) = fan velocity in feet per minute, ft/min.
CFM(ft3/min) = flow rate in cubic metres per minute, ft3/min.
D(in) = diameter in inches, in.
Fan Velocity Calculation:
1.Calculate the fan velocity for a fan with a CFM of 1200 and a diameter of 18 inches.
Given: CFM(ft3/min) = 1200, D(in) = 18 inches
Fan velocity, V(ft/m) = CFM(ft3/min) / (pi * (D(in)/12)2/4) / 60
V(ft/min) = 1200 /(3.14 * (18/12)2/4)/60
V(ft/min) = 1200/(1.77*60)
V(ft/min) = 11.32ft/min.
2.Determine the CFM required to achieve a fan velocity of 100 ft/min using a fan with a diameter of 24 inches.
Given: V(ft/min) = 100 ft/min, D(in) = 24 inches.
Fan velocity, V(ft/m) = CFM(ft3/min) / (pi * (D(in)/12)2/4) / 60
CFM(ft3/min) = V(ft/m) * (pi * (D(in)/12)2/4) * 60
CFM(ft3/min) = 100 * (3.14 * (24/12)2 /4) * 60
CFM(ft3/min) = 100 * 3.14 * 60
CFM(ft3/min) = 18840ft3/min.
Applications and Considerations:
- Ventilation Effectiveness: Proper calculation of fan velocity helps in maintaining effective ventilation, crucial for air quality and comfort in enclosed spaces.
- Cooling Efficiency: In industrial settings, correct fan velocity ensures efficient cooling of machinery and processes.
- Energy Consumption: Optimizing fan velocity can lead to significant energy savings by reducing the need for excessive fan speeds and frequent cycling.
- Noise Reduction: Lower velocities can minimize noise, an important consideration in residential and commercial HVAC design.
- System Durability: Ensuring that fan velocities are within design specifications can prolong system life by reducing wear and tear on fan components.