Presets and sharing
Inputs
Advanced settings
Results
Effective chimney height He
—
| Plume rise Δh | — |
|---|---|
| Modified chimney height hs' | — |
| Regime | — |
| Dominance | — |
| Formula used | — |
| Wind speed u_eff used for calculation | — |
Show intermediate value
| ΔT (K) | — |
|---|---|
| Fb (m^4/s^3) | — |
| Fm (m^4/s^2) | — |
| ΔTc (K) | — |
| s (1/s^2) | — |
| √s (1/s) | — |
Sensitivity graph (u sweep)
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Gaussian plume handoff
Pass the calculated effective stack height He to the Gaussian plume calculator to continue with downwind concentration estimates.
Assumptions & limits
- This is an approximation using a simple implementation of the Briggs formula. It does not handle building downwash (PRIME, etc.) or complex terrain.
- Results vary greatly depending on stability and temperature gradient settings. Please use the input assumptions clearly.
- Please do not use it for regulatory purposes, government submissions, or safety designs.
FAQ
What is the effective chimney height He?
He is the release height used by simple dispersion calculations: the physical stack height hs plus plume rise Δh. A larger He usually moves the plume centerline higher before it reaches downwind receptors.
How do you choose the stability (A to F)?
Use A to C for increasingly unstable daytime conditions, D for neutral cloudy or windy conditions, and E to F for stable night conditions with radiative cooling. Treat the class as an assumption to document, not as an automatic field measurement.
Can it be used for regulatory purposes?
No. This tool is for educational use only. Please use the official model in practice as it omits building downwash and terrain effects.
Related tools
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