Calculator Inputs
Example Data Table
| Project area | Volume | Generator output | Target ppm | Typical use note |
|---|---|---|---|---|
| Small finished room | 1,200 ft³ | 5,000 mg/hour | 2 ppm | Light odor after repair work |
| Vacant apartment | 6,500 ft³ | 10,000 mg/hour | 3 ppm | Moderate odor in open rooms |
| Basement cleanup | 9,000 ft³ | 15,000 mg/hour | 4 ppm | Moisture odor after drying |
| Construction punch area | 14,000 ft³ | 20,000 mg/hour | 3 ppm | Vacant site before final airing |
Formula Used
The calculator uses a room mass balance method. It converts ppm to mg/m³ with this planning factor:
Target mg/m³ = Target ppm × 1.96
It then adjusts treatment demand:
Demand mg/m³ = Target mg/m³ × Odor load multiplier × Safety factor
The loss rate is:
k = Air changes per hour + Natural decay per hour
When loss exists, estimated run time is:
Run time hours = -ln(1 - Demand × Volume × k / Effective output) / k
When loss is zero, the calculator uses:
Run time hours = Demand × Volume / Effective output
Effective output equals equipment output multiplied by efficiency percent.
How to Use This Calculator
- Enter the project name and choose the area type.
- Select feet or meters for the room dimensions.
- Enter length, width, and height, or use manual volume.
- Add the generator output from the equipment label.
- Set output efficiency for site conditions and machine age.
- Enter the target ppm for your planning estimate.
- Adjust leakage, decay, odor load, and safety factor.
- Press the calculate button and review the notes.
- Use the CSV or PDF buttons to save the result.
Use ozone only in unoccupied areas. Block access during treatment. Ventilate and test before reentry.
Ozone Run Time Planning for Construction
Ozone treatment is sometimes used after construction work. It may reduce stubborn odors from smoke, moisture, coatings, waste, or hidden contamination. A run time estimate helps teams size the job before using equipment. It also supports better scheduling, safer isolation, and clearer client communication.
Why Accurate Time Matters
Too little run time may leave odor sources active. Too much run time can create unnecessary risk and delay. Ozone is a strong oxidizer. It should never be used in occupied spaces. People, pets, plants, and sensitive materials should be removed before treatment begins. A written plan should define access control, ventilation, and final clearance steps.
What This Calculator Measures
This calculator estimates generator run time from room volume, generator output, target concentration, leakage, decay, and odor load. Volume sets the air mass that must be treated. Generator output sets how fast ozone is produced. Leakage and natural decay reduce the available ozone. Load and safety factors adjust for porous surfaces, furnishings, debris, or heavy contamination.
How to Read the Result
The recommended run time is an estimate, not a clearance approval. The result assumes the generator performs near the entered efficiency. It also assumes air mixes reasonably well. Poor airflow can leave pockets with lower treatment levels. Fans may help circulation, but they should be placed safely and used according to site rules.
Practical Site Guidance
Start with conservative settings for severe odor, damp materials, or large cavities. Use lower targets when materials are delicate. Seal obvious leaks before starting. Place warning notices at access points. Keep a log of start time, stop time, output setting, and reentry checks. After treatment, allow the clearance period to finish. Then ventilate and test before anyone returns.
Safety and Limitations
Ozone can irritate lungs and damage materials. It can react with chemicals and create secondary byproducts. The calculator does not replace an industrial hygienist, safety officer, equipment manual, or local regulations. Use measured ozone levels when possible. Treat the result as a planning estimate. Final reentry decisions should follow approved instruments and applicable exposure rules.
For complex projects, review multiple zones and calculate each space separately before work begins. Document assumptions, operator notes, and final readings for records.
FAQs
What does this ozone run time calculator estimate?
It estimates how long an ozone generator may need to run in a vacant project area. It uses volume, output, target concentration, leakage, decay, odor load, and safety settings.
Can people stay inside during ozone treatment?
No. Ozone treatment areas should be empty. People, pets, plants, and sensitive items should be removed. Access should stay blocked until ventilation, clearance time, and testing are complete.
What is generator output?
Generator output is the ozone production rate listed by the equipment maker. It is usually shown in milligrams per hour or grams per hour. Convert grams to milligrams before entering values.
Why does leakage change the result?
Leaks bring in fresh air and remove treated air. That lowers the ozone available in the space. Higher leakage usually requires longer run time or stronger equipment.
What does odor load multiplier mean?
It adjusts the estimate for porous materials, debris, smoke residue, moisture odor, or heavy contamination. A higher multiplier gives a more conservative planning result.
Why can a target be unreachable?
A target may be unreachable when generator output is too low for the room volume, leakage, and decay rate. Reduce leaks, lower the target, use more output, or divide the space.
Does the result approve safe reentry?
No. The result is only a planning estimate. Reentry should follow equipment instructions, site safety rules, proper ventilation, and measured ozone readings from approved instruments.
Can this calculator be used for every construction site?
It can help with planning, but it cannot cover every site condition. Chemical residues, airflow, temperature, humidity, and materials can change results. Use professional judgment and local rules.