- Pick a calculation mode: time check, airflow sizing, or efficiency sizing.
- Enter oxygen demand as a total, or as a rate and duration.
- Provide airflow and efficiency inputs, or set a target time for sizing.
- Optionally enter initial and target dissolved oxygen for a DO raise check.
- Press Calculate. Results appear above the form.
- Use CSV/PDF buttons to download a clean record for teams.
| Scenario | Tank (m³) | Demand basis | Airflow | OTE | Efficiency | Safety | Estimated time |
|---|---|---|---|---|---|---|---|
| Baseline check | 50 | 12 kg O₂ total | 120 m³/hr | 15% | 80% | 10% | Calculated by tool |
| Conservative plan | 50 | 3 kg O₂/hr × 5 hr | 140 m³/hr | 12% | 75% | 15% | Calculated by tool |
| Target runtime sizing | 80 | 18 kg O₂ total | — | 18% | 80% | 10% | Size airflow for 3 hours |
Purpose in construction aeration planning
Aeration is often required during commissioning of basins, temporary treatment trains, and odor-control holding tanks. This calculator turns site airflow and transfer assumptions into a practical runtime estimate, helping teams plan shifts, power needs, and monitoring windows without guesswork. It also supports scenario checks when equipment availability or access hours change.
Inputs that drive realistic runtime
Oxygen demand can be entered as a total requirement or as a rate across a defined operating period. Tank volume and dissolved oxygen targets add a separate allowance for initial DO lift, which is useful when startup water is low in oxygen. Airflow unit conversion keeps field readings consistent across meters. Air density and oxygen percentage can be adjusted for altitude, temperature, or enriched air systems.
Interpreting results for crews and supervisors
The output lists oxygen available in the air stream, the transferred oxygen rate, and the final aeration time in hours and minutes. When sizing airflow or efficiency, the calculator back-solves the needed capacity to hit a target duration. Use these values to compare blower settings, diffuser choices, and schedule constraints. Pair results with site readings to verify that dissolved oxygen increases at the expected rate.
Quality checks and conservative allowances
Transfer efficiency and system efficiency represent diffuser performance, fouling, mixing losses, and installation quality. A safety factor adds contingency for temperature swings, variable demand, or reduced oxygen transfer at depth changes. If required efficiency exceeds practical limits, the tool signals that airflow or time should be increased before execution. Review assumptions after cleaning diffusers, replacing hoses, or changing basin depth.
Documentation and handover benefits
Construction teams often need traceable calculations for method statements, QA records, and client reporting. The built-in CSV export supports spreadsheet reviews, while the PDF report provides a clean attachment for submittals. Re-running scenarios during site changes keeps the plan aligned with actual conditions and reduces rework risk. Capturing inputs alongside results helps future operators understand the commissioning basis and maintain consistent aeration practices.
What does aeration time represent in this tool?
It is the estimated runtime needed to supply the safety-adjusted oxygen requirement, based on airflow, oxygen content, transfer efficiency, and system efficiency. Results are shown in hours and minutes.
When should I use total demand instead of a demand rate?
Use total demand when you already have a project oxygen requirement from design notes or commissioning tests. Use a rate and duration when demand varies by operating hours or when planning staged startup periods.
How should I select oxygen transfer efficiency, OTE?
OTE depends on diffuser type, water depth, and fouling. Start with manufacturer or project values, then apply a conservative reduction for field conditions. If measured DO rise is slower than expected, lower OTE and recalculate.
Why is system efficiency separate from OTE?
System efficiency captures losses outside diffuser transfer, such as leaks, uneven distribution, mixing limitations, and aging equipment. Keeping it separate lets you refine estimates as installation quality and maintenance conditions change.
What if the required OTE is higher than practical?
A required OTE above typical field ranges indicates the target time is too short for the chosen airflow. Increase airflow, extend the target time, or improve diffuser performance and mixing, then run the calculation again.
Can I model enriched air or oxygen-assisted systems?
Yes. Adjust oxygen percentage and air density to match the supplied gas and conditions. Keep units consistent, and confirm that transfer efficiency assumptions reflect the equipment and water depth used on site.