---
title: "Mass loading"
description: "Mass loading is the particulate mass concentration in flue gas, typically expressed in g/Nm³ (boiler inlet) or mg/Nm³ (cleaned outlet). Mass loading at the inlet of an ESP or baghouse is the basis for sizing the equipment — higher inlet loading demands greater collecting area or more bag area to meet the same outlet target."
canonical_url: "https://sylio.co/glossary/mass-loading"
last_updated: "2026-06-28T02:29:34.601Z"
---

**Mass loading** is the particulate mass concentration in flue gas, typically expressed in g/Nm³ (boiler inlet) or mg/Nm³ (cleaned outlet). Mass loading at the inlet of an [ESP](/glossary/electrostatic-precipitator) or [baghouse](/glossary/baghouse) is the basis for sizing the equipment — higher inlet loading demands greater [collecting area](/glossary/specific-collection-area) or more bag area to meet the same outlet target.

## Typical inlet mass loadings

<table>
<thead>
  <tr>
    <th>
      Source
    </th>
    
    <th>
      Approximate inlet loading
    </th>
  </tr>
</thead>

<tbody>
  <tr>
    <td>
      Coal-fired utility boiler
    </td>
    
    <td>
      10–40 g/Nm³
    </td>
  </tr>
  
  <tr>
    <td>
      Cement kiln
    </td>
    
    <td>
      15–80 g/Nm³
    </td>
  </tr>
  
  <tr>
    <td>
      Iron-ore sintering
    </td>
    
    <td>
      5–15 g/Nm³
    </td>
  </tr>
  
  <tr>
    <td>
      WtE boiler
    </td>
    
    <td>
      4–10 g/Nm³
    </td>
  </tr>
  
  <tr>
    <td>
      Biomass boiler
    </td>
    
    <td>
      3–8 g/Nm³
    </td>
  </tr>
  
  <tr>
    <td>
      Gas-fired combined cycle
    </td>
    
    <td>
      < 0.05 g/Nm³
    </td>
  </tr>
</tbody>
</table>

Outlet loadings after particulate control are typically 5–30 mg/Nm³ (ESP) or 1–10 mg/Nm³ (baghouse), often with sub-1 mg/Nm³ achievable on tight-emission applications using [PTFE membrane bags](/glossary/ptfe-membrane-filter-bag).

## Related terms

- [Particulate matter](/glossary/particulate-matter)
- [Electrostatic precipitator](/glossary/electrostatic-precipitator)
- [Baghouse](/glossary/baghouse)
- [Collection efficiency](/glossary/collection-efficiency)