SCFH ↔ SCFM Converter
Convert Standard Cubic Feet per Hour (SCFH) to Standard Cubic Feet per Minute (SCFM) and vice-versa.
Note: “Standard” conditions typically assume 14.7 psia (1 atm) and 60°F. This may vary slightly depending on your specific industry standard (e.g., ASME vs CAGI).
SCFH to SCFM Conversion
If you are sizing an air compressor, designing a gas delivery system, or tuning HVAC equipment, you regularly encounter standard flow rate measurements. Converting between Standard Cubic Feet per Hour (SCFH) and Standard Cubic Feet per Minute (SCFM) is a routine necessity for engineers, technicians, and facility managers.
Because both units measure the exact same physical property volumetric flow rate under standardized conditions the conversion is purely a matter of time.
What Are SCFH and SCFM?
Before converting the numbers, it helps to know exactly what the acronyms stand for:
- SCFH (Standard Cubic Feet per Hour): This represents the volume of a gas (like air, nitrogen, or natural gas) that flows past a specific point in exactly one hour, assuming standardized environmental conditions.
- SCFM (Standard Cubic Feet per Minute): This is the exact same measurement, but tracked over a single minute instead of an hour.
Because an hour contains 60 minutes, the relationship between the two is fixed. An SCFH value will always be 60 times larger than its SCFM counterpart for the same flow system.
The Importance of “Standard” Conditions
You might wonder why the word “Standard” is necessary. Why not just use Cubic Feet per Minute (CFM)?
Gases are highly compressible. The volume of a gas changes drastically depending on the surrounding temperature and pressure. If you measure a cubic foot of air at the top of a mountain on a freezing day, it contains a completely different amount of air molecules than a cubic foot measured in a hot, pressurized valley.
To solve this, industries use Standard Conditions to create a level playing field. While different organizations (like ASME, NIST, or CAGI) have slightly different baselines, standard conditions typically assume:
- Pressure: 14.7 psia (1 atmosphere / sea level)
- Temperature: 60°F (15.6°C) or 68°F (20°C)
- Relative Humidity: 0% (dry gas)
By adding the “S” to CFM or CFH, you are stating: “This is the volume this gas would occupy if we brought it back to sea level at room temperature.” Since this calculator handles a time-based conversion, it assumes the standard conditions remain constant throughout your calculation.
Common Industry Applications
1. Sizing Air Compressors and Pneumatic Tools Industrial air compressors and the pneumatic tools they run (like impact wrenches, paint sprayers, or sandblasters) almost exclusively use SCFM. It tells the operator exactly how much air is available right now. However, the overall facility air consumption over a shift might be calculated in SCFH to monitor daily energy costs.
2. Gas Appliances and Burners Natural gas lines, residential furnaces, and commercial boilers usually rate their fuel consumption in SCFH. If a technician needs to troubleshoot the gas flow in real-time using a digital meter, they often convert that rating to SCFM to get a faster, minute-by-minute reading.
3. Nitrogen Generation and Medical Gases Facilities that generate their own nitrogen or supply medical oxygen look at the big picture. A generator’s output is often listed in SCFH or SCFD (Standard Cubic Feet per Day) to show total production capacity, but the piping and regulators are sized based on the peak SCFM demand of the hospital or factory floor.
How to Calculate the Conversion Manually
If you don’t have this calculator handy, the math is straightforward. Because you are only converting the unit of time, the density and pressure of the gas do not require complex gas law equations.
To find your minute flow rate, divide your hourly flow rate by 60. To find your hourly flow rate, multiply your minute flow rate by 60.
Conversion Formulas
Convert SCFH to SCFM:
Convert SCFM to SCFH:
FAQs
Q1. What is the difference between ACFM and SCFM?
A: Actual Cubic Feet per Minute (ACFM) measures the volume of gas flowing at the exact, real-world temperature and pressure of the system it is currently in. SCFM takes that exact same gas and calculates what its volume would be if it were at standard, sea-level conditions.
Q2. Can I use this calculator for liquids like water?
A: No. SCFH and SCFM are used exclusively for gases because gases are compressible. For liquids, you would standard units like Gallons per Minute (GPM) or Liters per Hour (LPH), which do not require “standardized” environmental baseline adjustments.
Q3. How many SCFM are in 1 SCFH?
A: 1 SCFH is equal to 0.01666… SCFM. (Calculated as 1 divided by 60).
Sources: XConvert, Proportion-Air, ConvertUnits, Kyle’s Converter, CalculatorsHub (via LinkedIn), PRM Filtration, Airpack, Mass Flow Converter, Instrumentation & Control, The Lee Company.