CFM to kW Conversion Calculator

This cfm to kw conversion calculator is created to convert Cubic Feet per Minute (CFM) to Kilowatts (kW).

CFM measures the volumetric flow rate of air, while kW quantifies electrical power. The relationship between these units is not straightforward, as it depends on several factors, including air pressure and temperature.

Consider a large industrial fan moving 10,000 CFM of air. To determine the electrical power required to operate this fan, you’d need to convert CFM to kW. This is where the CFM to kW calculator comes in handy, taking into account the specific system parameters to provide an accurate conversion.

CFM to kW Calculator

CFM	Pressure (psi)	Efficiency	kW (calculated)
100	100	0.80	40.6
200	100	0.80	81.2
300	100	0.80	121.8
400	100	0.80	162.4
500	100	0.80	203.0
600	100	0.80	243.6
700	100	0.80	284.2
800	100	0.80	324.8
900	100	0.80	365.4
1000	100	0.80	406.0
100	125	0.85	47.1
200	125	0.85	94.2
300	125	0.85	141.3
400	125	0.85	188.4
500	125	0.85	235.5
600	125	0.85	282.6
700	125	0.85	329.7
800	125	0.85	376.8
900	125	0.85	423.9
1000	125	0.85	471.0
100	150	0.90	52.4
200	150	0.90	104.8
300	150	0.90	157.2
400	150	0.90	209.6
500	150	0.90	262.0
600	150	0.90	314.4
700	150	0.90	366.8
800	150	0.90	419.2
900	150	0.90	471.6
1000	150	0.90	524.0

CFM to kW Conversion Formula

kW = (CFM × Pressure (psi) × 0.746) / (229 × Efficiency)

Where:

• CFM is the air flow rate
• Pressure is in pounds per square inch (psi)
• 0.746 is the conversion factor from horsepower to kilowatts
• 229 is a constant derived from thermodynamic principles
• Efficiency is the overall system efficiency (typically 0.7 to 0.9)

Let’s convert 500 CFM at 100 psi with 80% efficiency:

kW = (500 × 100 × 0.746) / (229 × 0.8) ≈ 203.3

500 CFM of air at 100 psi with 80% efficiency requires approximately 203.3 kW of power.

How do I convert CFM to kW?

To convert CFM to kW, follow these steps:

• Determine the air flow rate in CFM
• Measure the air pressure in psi
• Estimate the system efficiency
• Apply the conversion formula
• Calculate the result

Suppose you have an air compressor with the following specifications:

• Air flow rate: 750 CFM
• Pressure: 125 psi
• System efficiency: 85%

Step 1: Air flow rate is given as 750 CFM
Step 2: Pressure is 125 psi
Step 3: Efficiency is 0.85 (85%)
Step 4: Apply the formula
kW = (750 × 125 × 0.746) / (229 × 0.85)
Step 5: Calculate
kW ≈ 452.5

The 750 CFM air compressor operating at 125 psi with 85% efficiency requires approximately 452.5 kW of power.

How many CFM per kW?

To find CFM per kW, we rearrange the conversion formula:

CFM/kW = (229 × Efficiency) / (Pressure (psi) × 0.746)

Let’s calculate CFM per kW for a system operating at 90 psi with 75% efficiency:

CFM/kW = (229 × 0.75) / (90 × 0.746) ≈ 2.57

This means that under these conditions, you get approximately 2.57 CFM for every kW of power input.

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