How To Get the Right Air to Cloth Ratio for Your Dust Collector

Dust collector air to cloth ratio is a critical measure to ensure your system is performing efficiently.

How to get the right air to cloth ratio

What is Air-to-Cloth Ratio?

Air-to-Cloth ratio (a.k.a. Air-to-Media) is defined as a measurement of the amount of air passing through one square foot of filter media.

Which is better, Lower or Higher Air-to-Cloth Ratio?

Generally the lower your air-to-cloth ratio, the more effective your system is at removing dust from your work environment.

If you operate on a higher air-to-cloth ratio, one of the common issues you will encounter is a decrease in suction. This happens because there is too much dust to capture with an insufficient amount of filter media. The filter cake on your bag eventually builds up too quickly. As a result, your air velocity and suction decreases. From there it’s a domino effect and your plant air quality decreases, filters clog quicker, and valve life expectancy is impacted. So, you’ll be performing change-outs more frequently which will cost both time and money.

How to Calculate Air-to-Cloth Ratio

To calculate air-to-cloth ratio, take the amount of airflow (CFM) and divide that by the amount of filter area within your dust collector. 

For example, if you’re calculating for a cartridge collector, a typical range would be a 4:1 air to cloth ratio.  Keep in mind that environments with a large ventilation area and more pick up points require a system with a higher CFM to provide adequate suction.  Would you like to know which air to cloth ratio may be right for your project? If so, download our air to cloth guide which provides the recommended ratio for a wide variety of applications.

Why is right Air-to-Cloth ratio important?

What are the negative effects of improper Air-to-Cloth ratio?

  • Poor venting, therefore causing damage to equipment
  • Incur high pressure drops 
  • Impacts your air velocity
  • Excessive use of compressed air

Related Resources:

Filter Bag Media Quiz

How to Get the Right Dust Collector for your Application

What Volume Dust Collector do I need?

4 Comments

  1. Om mishra

    I would like to know , if in one of cement plant , packing plant area our air to cloth ratio is 2.1 m3 / m2/ min . for normal cylindrical polyester bag of size 149*3.6 meter long . can we switch into Cartridrige bags ??? In the same bag filter . Air volume is 40000 m3 / hrs

    • Joyce Nagy

      Short answer is yes, you can switch to a pleated cartridge filter in place of any top or bottom load filter bags in a pulse jet baghouse. However, we need to make sure the pleated filters will work in your specific application. Dusts with moisture or that easily compact are not usually good candidates for a pleated cartridge filter as the dust will be difficult to pulse out of the pleats which can cause the filter to plug. We also need to consider the air to cloth ratio and interstitial velocity to ensure the dust can drop out of the air stream once pulsed off the filter.

      Lets make sure I didn’t make any mistakes when converting units. Your air volume is 666.7 m3/min and you have 188 filters measuring 149mm diameter x 3600mm long, correct? This gets us the 2.1 m3/m2/min air to cloth ratio.

      If you are looking to change all 188 filters to pleated cartridge filters your air to cloth ratio would drop to 0.77 m3/m2/min which should work provided the material is dry and does not compact in the pleats of the filter. If the goal is to reduce the overall number of filters you need to take into account not only the air to cloth ratio but also the interstitial velocity.

    • Joyce Nagy

      Hello Chad,

      Thank you for reaching out to us. An account manager will be in touch with you shortly to get you the information you are looking for.

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