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Fan Affinity Laws Calculator (RPM, Airflow, Pressure, Power)

Easily calculate and compute fan affinity laws calculator (rpm, airflow, pressure, power) with accurate equations, live formulas, and expert guidance.

Calculated Result
4,000 CFM

New Airflow Q2 (CFM)

New Airflow Q2 (CFM)

4,000 CFM

New Flow Cfm

4000

New Pressure In Wg

1.28

New Bhp

1.54

Speed Ratio

0.8

4,000 — CFM

Calculation Breakdown

  1. Applied FormulaApplies the three fundamental fan affinity laws to project new volumetric airflow, static pressure, and motor shaft brake horsepower (BHP) when changing fan impeller RPM.\frac{Q_2}{Q_1} = \frac{N_2}{N_1}, \quad \frac{P_2}{P_1} = \left(\frac{N_2}{N_1}\right)^2, \quad \frac{\text{BHP}_2}{\text{BHP}_1} = \left(\frac{N_2}{N_1}\right)^3

Fan Affinity Laws Metric Output

Interactive visualization based on your current inputs

Calculated Value
0.01.0k2.0k3.0k4.0kNew Airflow Q2 (CFM)

What Is the Fan Affinity Laws Calculator (RPM, Airflow, Pressure, Power)?

This tool computes fan affinity laws calculator (rpm, airflow, pressure, power) with high precision arithmetic.

How Does the Fan Affinity Laws Calculator (RPM, Airflow, Pressure, Power) Work?

Applies the three fundamental fan affinity laws to project new volumetric airflow, static pressure, and motor shaft brake horsepower (BHP) when changing fan impeller RPM.

Fan Affinity Laws Calculator (RPM, Airflow, Pressure, Power) Formula & Variables

The core mathematical equation utilized by this calculator is expressed as:

Q2Q1=N2N1,P2P1=(N2N1)2,BHP2BHP1=(N2N1)3\frac{Q_2}{Q_1} = \frac{N_2}{N_1}, \quad \frac{P_2}{P_1} = \left(\frac{N_2}{N_1}\right)^2, \quad \frac{\text{BHP}_2}{\text{BHP}_1} = \left(\frac{N_2}{N_1}\right)^3

Applies the three fundamental fan affinity laws to project new volumetric airflow, static pressure, and motor shaft brake horsepower (BHP) when changing fan impeller RPM.

How to Use the Fan Affinity Laws Calculator (RPM, Airflow, Pressure, Power)

  1. Enter your parameters into the designated input fields to calculate the result immediately.

Step-by-Step Example Calculation

Fan Affinity Laws Calculator (RPM, Airflow, Pressure, Power) Example

Input Values:

initialRpmN1:1200
newRpmN2:960
initialFlowCfm:5000
initialStaticPressureInWg:2
initialBhp:3
Worked Steps: Sample evaluation based on standard reference conditions.

Understanding Your Result

The calculated primary figure indicates the optimal or required CFM.

Factors That Affect the Result

  • Measurement tolerances, operational variance, and real-world conditions.

When Should You Use This Calculator?

  • Everyday budgeting, technical homework, professional estimation, and household projects.

Assumptions & Limitations

  • Assumes standard atmospheric or environmental parameters unless specified.

Frequently Asked Questions

Calculation Accuracy & Reference Note

Double-precision IEEE 754 arithmetic with validated empirical constants.

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