Energy Efficiency Reference/Industrial/Compressed Air/Power & Energy

Analysis Tools & Methods


This section of the assessment guide presents analysis tools and methods that will be used later in the recommendation section. The recommendation section outlines data required, procedures, and ideas needed to analyze energy use in compressed air systems. Refer to equation in this chapter when directed by the recommendation section.

Standard Analysis Methods'

Calculate Existing Energy Use Profile Before analyzing potential recommendations you must be able to calculate compressor energy use under different operating conditions and control strategies.

Data Required

  • All Standard Air Compressor Data

Tools Required

  • Air Compressor Data Worksheets
  • Measured Operating Conditions worksheets
  • Air Compressor Savings Worksheets

The Measured Operating Conditions and the Air Compressor Savings Worksheets, found in the Data Collection Tools section, provide a convenient way to record data required to calculate energy use. Calculating energy use requires an understanding of the relationship between power and airflow for difference control strategies. These relationships are outlined in the Technology Primer section as well as the Appendix. Use this section as a guide to using these relationships to calculate air compressor energy use. Enter measured data into the Measured Operating Conditions Worksheet. The subsequent calculation procedure depends on whether you entered airflow (%C) or power (kW). examples of how to calculate energy use are provided for each case. apply this method to each operating condition you have identified.

Calculating Existing Energy Use(using measured power(kW)): Data Entry, Enter annual hours and power into the Existing Conditions table of the Air Compressor Savings Worksheet. Divide the compressor power of the selected operating condition by the power at full load. Calculated energy use by multiplying power by annual hours of operation for each operating condition. Calculate Percent Power from Power:

1. Percent Power = Operating Point Power / Full Load Power

2. Calculate Energy from Operating Point Power Energy = Power x Annual Operating Hours

Energy Calculations (using measured power (kW)):

3. Calculate Airflow The relationship between airflow and power depends on control strategy. Conversion formulas for typical controls follow