---
title: "Reverse-air baghouse"
description: "A reverse-air baghouse cleans its filter bags by isolating one compartment at a time from the main gas flow and forcing low-pressure clean air through the bags in the reverse direction. The reverse flow gently collapses the cake from the bag surface, which then falls into the hopper. Reverse-air design is common on coal-fired utility-boiler baghouses and on older industrial installations."
canonical_url: "https://sylio.co/glossary/reverse-air-baghouse"
last_updated: "2026-06-28T02:29:25.208Z"
---

A **reverse-air baghouse** cleans its [filter bags](/glossary/filter-bag) by isolating one compartment at a time from the main gas flow and forcing low-pressure clean air through the bags in the reverse direction. The reverse flow gently collapses the cake from the bag surface, which then falls into the hopper. Reverse-air design is common on coal-fired utility-boiler baghouses and on older industrial installations.

## Strengths and weaknesses

<table>
<thead>
  <tr>
    <th>
      Strength
    </th>
    
    <th>
      Weakness
    </th>
  </tr>
</thead>

<tbody>
  <tr>
    <td>
      Gentle cleaning extends bag life
    </td>
    
    <td>
      Compartment must be offline during cleaning
    </td>
  </tr>
  
  <tr>
    <td>
      Low compressed-air consumption
    </td>
    
    <td>
      Requires a larger total bag area for the same duty
    </td>
  </tr>
  
  <tr>
    <td>
      Tolerates long fibreglass bags
    </td>
    
    <td>
      Slower cleaning cycle
    </td>
  </tr>
  
  <tr>
    <td>
      Lower bag wear than pulse-jet
    </td>
    
    <td>
      Cleaning intensity not easily varied
    </td>
  </tr>
</tbody>
</table>

## Where sonic horns help

The gentle nature of reverse-air cleaning leaves residual cake that gradually accumulates over time. [Sonic horns](/glossary/sonic-horn) mounted at the compartment roof break up the residual cake without the bag wear of more aggressive primary cleaning, defer the need for offline manual cleaning and reduce average [differential pressure](/glossary/differential-pressure-baghouse).

## Related terms

- [Baghouse](/glossary/baghouse)
- [Filter bag](/glossary/filter-bag)
- [Compartment isolation](/glossary/compartment-isolation)
- [Sonic horn](/glossary/sonic-horn)