1. What is Standard Cubic Feet?

Standard Cubic Feet per Minute (SCFM) is the volumetric flow rate of a gas corrected to standard conditions of temperature and pressure. It provides a consistent basis for comparing gas flow rates.

2. How Does the Calculator Work?

The calculator uses the SCFM conversion formula:

Where:

• \( CFM \) — Actual cubic feet per minute
• \( P \) — Absolute pressure (psia)
• \( T \) — Absolute temperature (°R = °F + 459.67)
• 14.7 — Standard pressure (psi at sea level)
• 528 — Standard temperature (°R = 68°F + 459.67)

Explanation: The equation converts actual flow rate to what it would be at standard conditions (68°F and 14.7 psi).

3. Importance of SCFM Calculation

Details: SCFM is crucial for comparing compressor performance, sizing pneumatic systems, and ensuring proper operation of air-powered tools across different environmental conditions.

4. Using the Calculator

Tips: Enter CFM (actual flow rate), absolute pressure (psig + 14.7), and temperature in °F. All values must be valid (CFM > 0, pressure > 0, temperature > absolute zero).

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between CFM and SCFM?
A: CFM is actual flow rate at current conditions, while SCFM is flow rate corrected to standard conditions for comparison.

Q2: Why use 14.7 psi and 68°F as standard?
A: These represent typical sea-level atmospheric conditions (1 atm at 20°C/68°F), providing a consistent reference point.

Q3: How does altitude affect SCFM?
A: Higher altitudes have lower atmospheric pressure, so actual CFM will be higher than SCFM for the same mass flow.

Q4: When should I use ACFM vs SCFM?
A: Use SCFM for equipment specifications and comparisons, ACFM for actual system performance at local conditions.

Q5: What about metric units?
A: The metric equivalent is Nm³/h (normal cubic meters per hour) at 1 atm and 0°C.