Calculator
Example data table
| Scenario | Material used | VOC content | Capture | Control | Controlled per operation |
|---|---|---|---|---|---|
| Solvent wipe | 10 L @ 0.78 kg/L | 95% wt | 0% | 0% | 7.410 kg |
| Coating line | 50 L @ 0.90 kg/L | 45% wt | 70% | 90% | 10.575 kg |
| Fuel transfer | 1200 kg @ 0.74 kg/L | 420 g/L | 60% | 98% | 209.741 kg |
Formula used
- If weight percent is used: VOC = Mass × (VOC% / 100)
- If g/L is used: VOC = (g/L × Liters) / 1000
- When needed: Mass = Liters × Density, Liters = Mass / Density
- Captured = VOC × CaptureEff
- Fugitive = VOC − Captured
- Destroyed = Captured × ControlEff
- Stack = Captured − Destroyed
- Controlled total = Fugitive + Stack
- Daily = PerOperation × OperationsPerDay
- Annual = Daily × DaysPerYear
- Rate (g/s) = (Daily kg × 1000) / (HoursPerDay × 3600)
How to use this calculator
- Enter material used per operation and pick the unit.
- Provide density to convert between mass and volume.
- Select VOC basis, then enter the matching content value.
- Set capture and control efficiencies for your system.
- Enter operations, hours, and days to scale outputs.
- Press calculate, then export results if needed.
VOC sources and activity data
Volatile organic compounds are emitted when solvents, coatings, fuels, and cleaners evaporate during use, transfer, mixing, and drying. A sound inventory starts with activity per operation: material used, unit, and density, then repeats that operation across shifts and the year. This calculator translates those drivers into uncontrolled mass, controlled mass, and reduction percent, helping connect purchasing records to emission totals for internal tracking and external reporting.
Selecting a VOC content basis
VOC content may be provided as weight percent or as grams per liter. Weight percent pairs naturally with mass-based usage and is common on safety data sheets. Grams per liter is convenient for coatings and liquids and aligns with volume metering. When inputs mix mass and volume, density bridges the gap so that VOC mass is calculated consistently in kilograms.
Capture efficiency and control efficiency
Capture efficiency represents the fraction of vapors routed to a control device, while control efficiency represents the fraction removed or destroyed once captured. The model divides emissions into fugitives that escape collection and stack releases that pass through controls. This split supports scenario testing: improving hoods and ducting raises capture, while tuning oxidizers, adsorbers, or condensers raises control.
Scaling, rates, and conversions
Per-operation VOC mass is scaled to daily totals using operations per day, then annual totals using days per year. For rate-based limits, the calculator estimates an average grams-per-second rate by spreading daily kilograms across operating hours. It also converts annual controlled kilograms to short tons per year using 2.2046 pounds per kilogram and 2,000 pounds per short ton.
Data checks and uncertainty management
Use density and VOC content from supplier specifications at the same temperature and formulation. If efficiencies are uncertain, start with uncontrolled emissions, then apply conservative capture and control values and document your assumptions. Compare annual totals against purchase logs, production counts, and waste manifests to confirm reasonableness. Update scenarios when materials, throughput, or control performance changes.
For screening, run a zero-control case and a controlled case to bracket results. When VOC is reported as exempt plus non-exempt, enter only the regulated fraction. Keep units consistent, and store exported CSV/PDF with calculation date. for audits.
FAQs
What does the calculator consider “uncontrolled” VOC emissions?
Uncontrolled emissions are the VOC mass per operation before any capture or control is applied. They represent potential releases if vapors are not routed to a control device.
How do I choose a density value?
Use the product technical sheet or safety data sheet when available. If the material is a blend, use a measured density at operating temperature because density affects the mass–volume conversion.
What is the difference between capture efficiency and control efficiency?
Capture efficiency is how much vapor reaches the control device. Control efficiency is how much of that captured vapor is removed or destroyed. Both factors multiply to determine controlled stack emissions.
How can I model multiple products or batches?
Run the calculator once per product or batch, export each CSV, then sum annual controlled totals in a spreadsheet. This keeps density and VOC content aligned with the correct material.
My VOC content is in g/gal. What should I do?
Convert to g/L before entry. Use 1 US gallon = 3.78541 liters, then divide g/gal by 3.78541 to get g/L. Keep the same basis across scenarios.
Why does the grams-per-second rate look small or large?
The rate is an average over the operating hours you enter. Shorter hours concentrate the same daily mass into a higher rate, while longer hours spread it into a lower rate.