What Happens During a Compressed Air Audit
A thorough compressed air audit typically involves three phases: data collection, analysis, and recommendations. Here is what each phase involves.
Data Collection. Auditors install data loggers on your compressed air system — typically for one to two weeks — to capture real operating data across all production conditions. Measured parameters include compressor power consumption (kW), system pressure at multiple points, flow rate (CFM), temperature, and compressor duty cycle. The logging period should capture your peak production days, off-shift periods, and weekend conditions to give a complete picture of demand variation.
Simultaneously, auditors perform an ultrasonic leak survey — walking the facility with an ultrasonic detector to identify and document every compressed air leak, noting its location, estimated leak rate, and estimated annual energy cost.
Analysis. The logged data is analyzed to determine actual versus nameplate compressor capacity, system pressure losses (the difference between compressor output pressure and point-of-use pressure), demand variation across shifts and days, estimated leak volume as a percentage of total output, and specific energy consumption (kW per CFM delivered) compared to industry benchmarks.
Recommendations. The audit report documents findings and provides a prioritized list of improvement opportunities with estimated implementation costs and energy savings for each. Good audit reports include payback period calculations so you can evaluate each recommendation as an investment decision.
What Compressed Air Audits Typically Find
After conducting audits across hundreds of Midwest manufacturing facilities, Brabazon's team has found a consistent set of issues that appear repeatedly:
- Leaks: In most facilities, 20–35% of compressed air output is lost to leaks. The average leak survey identifies 20–60+ individual leak points. Annual energy cost of total leakage commonly runs $5,000–$50,000 depending on facility size and electricity rate.
- Excessive system pressure: Many facilities run at higher pressure than their highest-demand application actually requires, typically because of pressure drop through poorly designed or undersized piping. Correcting the root cause and lowering system pressure by 10 PSI saves approximately 5% in compressor energy — every year, indefinitely.
- Compressor over-capacity: Facilities often find their installed compressor capacity significantly exceeds actual peak demand, sometimes by 50–100%. This happens because compressors were sized for theoretical future growth that never materialized, or because compressors were added over time without decommissioning older units.
- Inefficient compressor controls: Multiple compressor installations without proper sequencing controls result in compressors fighting each other — one running loaded while another runs unloaded — wasting energy continuously.