Annual station electricity, air volume, operating hours, electricity price and station specific energy.
Compressed air audit report example
See how a compressed air diagnosis report should be structured
A useful compressed air audit report should not start and end with leakage. It should separate station efficiency, pressure mismatch, equipment selection, control waste, distribution loss, dryer purge and heat recovery before presenting the total saving.
- Report structure follows five engineering modules: baseline, equipment, station control, distribution/end-use and heat recovery.
- Only found optimization points should be shown in the final report, with calculation basis and overlap note.
- Manual field data is enough for screening; time-series data improves pressure, load and control diagnosis.
Report modules
The compressed air report should separate five types of findings
These modules reduce double counting. Pressure reduction can affect compressor energy, leakage and end-use demand; equipment replacement can overlap with control waste; heat recovery should not be mixed into compressed air electricity savings.
Compressor type, rated power, rated flow, rated pressure, pressure class, specific power and replacement or retrofit candidates.
Average pressure, pressure band, sequencing, unload hours, VFD low-load operation, IGV/BOV behavior and mixed-fleet dispatch.
Pressure drop, leakage, dryer purge, drain losses, inappropriate end-use demand and air-quality requirement.
Cooling method, useful heat demand, required temperature, coincidence hours and value against another energy source.
Priority order, measurement plan, supplier questions and which items should be verified before investment.
Example output
What a report-ready compressed air finding looks like
The example below shows the level of structure a buyer should expect. It shows only optimization points that are meaningful enough to discuss, not every possible rule in the diagnostic engine.
Finding
Report conclusion
Calculation / evidence basis
Pressure class mismatch
Rated pressure is higher than the actual end-use requirement. Review low-pressure compressor replacement or impeller/stage retrofit where applicable.
Compare required end-use pressure, supply pressure and compressor rated pressure; estimate pressure-related power reduction with the overlap rule for leakage and end-use demand.
Fixed-speed unload waste
Fixed-speed screw units show unloaded running during the measurement period. Improve sequencing or replace the trim role with a better matched unit.
Use controller run hours and loaded hours over a recent period; calculate unloaded hours and apply no-load power ratio by compressor type.
Centrifugal blow-off risk
IGV position and BOV/blow-off evidence indicate possible air bypass or operation outside the efficient turndown range.
Use IGV opening, BOV status or blow-off hours when available; estimate flow and power waste with conservative compressor-specific assumptions.
Dryer purge and pressure drop
Desiccant dryer regeneration loss and aftertreatment pressure drop should be evaluated against air-quality requirement and dew point control.
Use dryer type, purge ratio or target purge benchmark, inlet/outlet pressure and required dew point or oil/water quality class.
Useful heat recovery
Recoverable compressor heat can offset hot water, make-up water, space heating or process heat when demand and temperature match.
Use compressor cooling method, operating hours, recoverable heat factor, useful heat demand and alternative energy price.
Equipment selection
A compressed air report should say what can be changed, not only what is wrong.
When the data supports it, the report should translate the diagnosis into specific engineering options: reduce pressure class, replace a low-efficiency unit, change the trim compressor role, review centrifugal impeller or stage configuration, or avoid operating a large machine at a poor load point.
The report should still be careful. Final replacement selection requires supplier curves, site constraints and investment review. The pre-audit report should identify the likely opportunity and quantify a defensible screening value.
Manual and trend data
What users should enter before generating the report
The tool should stay practical for field engineers. Manual data is used for screening; one combined trend table can be imported when deeper pressure and control diagnosis is available.
- Annual station electricity, annual air volume or average air flow.
- Operating hours, electricity price and minimum end-use pressure requirement.
- Average supply pressure and pressure upper / lower band.
- Compressor type, rated power, rated flow and rated pressure for each unit.
- Controller counters: run hours, load hours, average load ratio, IGV or BOV when available.
- Dryer type, purge ratio if known, pressure drop, leakage or night-baseline observation.
- Timestamp, station power, main air flow and header pressure.
- Aftertreatment inlet/outlet pressure and critical end-use pressure when available.
- Per-compressor power, load status, loading ratio, IGV or BOV status when available.
- Production or operating boundary tags only when they change interpretation of load variation.
Related report paths
Use the compressed air example inside the full integrated-energy flow
Compressed air is often one part of a larger plant energy opportunity. The full sample report shows how compressed air findings remain separate from chiller plant, steam, heat pump, electrical and multi-energy measures.
FAQ
Compressed air audit report questions
What should a compressed air audit report include?
It should include station baseline, air volume, electricity cost, pressure requirement, compressor equipment data, control loss, distribution loss, leakage, dryer purge, heat recovery and calculation trace.
Is leakage the main part of a compressed air saving estimate?
Leakage can be important, but pressure, unload loss, centrifugal blow-off, dryer purge and equipment selection can also drive material savings. The report should separate these mechanisms before totals are shown.
Can controller readings replace a full data logger?
For screening, yes. Run hours, load hours, average load ratio, IGV position and BOV information can support a first diagnosis. Time-series data improves confidence and control analysis.
Can the report recommend compressor replacement?
It can flag replacement or retrofit candidates based on rated pressure, specific power, capacity mix and operating pattern. Final selection still requires supplier validation and site constraints.
Run the compressed air diagnosis with your own station data.
Start with field-readable values, then import trend data when it helps validate pressure, load and control behavior.