1. What is an Air Hose CFM Calculator?

Definition: This calculator determines the air flow rate in cubic feet per minute (CFM) through a hose based on air velocity and hose cross-sectional area.

Purpose: It helps pneumatic system designers, HVAC technicians, and industrial professionals properly size air hoses and understand system requirements.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q_{cfm} \) — Air flow rate (cubic feet per minute)
• \( V \) — Air velocity (feet per second)
• \( A \) — Cross-sectional area of hose (square feet)
• 60 — Conversion factor (seconds to minutes)

Explanation: The formula converts velocity in feet per second to volume flow in cubic feet per minute by multiplying by the hose area and time conversion.

3. Importance of CFM Calculation

Details: Proper CFM calculation ensures adequate air supply for tools, prevents pressure drops, and helps select properly sized compressors and hoses.

4. Using the Calculator

Tips: Enter the air velocity in ft/s and hose area in ft². For circular hoses, area = π × (diameter/2)². All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical air velocity for pneumatic systems?
A: Most systems operate between 20-30 ft/s, with 25 ft/s being a common design velocity.

Q2: How do I calculate hose area for a circular hose?
A: Area = π × r² where r is the radius in feet (diameter/2 converted to feet).

Q3: Why multiply by 60 in the formula?
A: This converts seconds to minutes since CFM is cubic feet per minute while velocity is in feet per second.

Q4: What CFM do common air tools require?
A: Small tools need 2-5 CFM, medium tools 5-10 CFM, and large tools may require 10-20+ CFM.

Q5: How does hose length affect CFM?
A: Longer hoses increase friction loss, reducing effective CFM at the tool end - consider pressure drop calculations for long runs.