Rectangular Stack Port Checker

EPA Method 1 – Rectangular Stack Port Checker

Stack Width:

Stack Height:

Unit:
Inches Feet Meters Centimeters Upstream Distance:

Downstream Distance:

🟫 Rectangular Stack – EPA Method 1

✅ Key Points:

For non-circular stacks, the hydraulic diameter is used instead of direct width/height.

The hydraulic diameter approximates the flow characteristics of a round duct.

✅ Formulas:

Let:

$W$ = width of the duct

$H$ = height of the duct

Dh​ = hydraulic diameter
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📐 Hydraulic Diameter:

$$D_h=\frac{2\times W\times H}{W+H}$$

📌 Required Distances:

• Upstream distance:

  $$L_{up}\ge 8\times D_h$$

• Downstream distance:

  $$L_{down}\ge 2\times D_h$$

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✅ Additional Notes:

1. These requirements help ensure fully developed flow profiles, critical for accurate sampling.
2. If required distances cannot be met, consult EPA Method 1 for alternative locations and documentation requirements.
3. Unit consistency is important: use the same units (e.g., inches, meters) for all dimensions.