How can air compressor efficiency be measured by using a electrical power meter and a compressed air flow meter?

Air compressor efficiency can be assessed by measuring the power input and the compressed air output, and calculating a value called specific power.

• An electrical power meter measures the actual power consumed by the compressor, typically in kilowatts (kW) or horsepower (HP).
• A compressed air flow meter measures the volume of air delivered by the compressor, usually in cubic meters per hour (m³/h) or cubic feet per minute (CFM).

To determine efficiency, divide the power input by the airflow output:

Specific Power = Power Input / Air Flow Output
Example: kW per m³/h or HP per CFM

This specific power value represents how much energy is needed to produce a given amount of compressed air. Lower values indicate higher efficiency, meaning less energy is required to generate the same volume of air.

Different units are used depending on the region:

• In Europe and many other countries, kW per m³/h is common.
• In the USA, HP per CFM is more frequently used.

By continuously monitoring both power and flow, you can track the compressor’s efficiency over time, identify energy losses, and improve system performance.