Your Questions Answered

Customers bring up all sorts of interesting questions via the LiveChat feature on our website. So, we’ve decided to publish a quarterly blog that captures a few hot topics and the answers provided by our knowledgeable team. In this one, we cover some of the most frequently asked questions about filters.

  • How long do BOFA filters last?

There are a lot of factors governing filter life, for example, the process, frequency, and duration of operation, and the materials being worked.

Rather than thinking about filter life in terms of time, a more accurate measure might be to think about units of product, because a 24/7 high-speed laser line will require a very different filter exchange schedule to, say, a dental laboratory.

Our engineers work closely with customers to configure filtration systems by taking all these factors into account. They look at the manufacturing process (such as lasering, electronics, and additive manufacturing), the material being worked, and the volume of airborne particulate likely to be generated. In the case of certain laser applications, this can include accounting for the “kerf” – the width of material removed by a cutting process, or the depth and area of the ablation for laser engraving or marking processes.

And remember, BOFA systems incorporate filtration saturation sensors and many of our units offer remote diagnostics, so monitoring filter performance and lifecycle can be undertaken in real-time. This enables exchanges to be scheduled as part of maintenance routines to minimize downtime.

One point worth emphasizing is never to be tempted to replace BOFA-approved filters with what might be considered alternatives. BOFA filters have been purpose-designed to work with the extractor they reside in and take account of many factors, such as face velocity, pressure drop, residency time, and structural integrity.

Installing non-genuine replacements will risk impaired filter efficiency or even filter rupture, leading potentially to downtime and a negative impact on product quality.


  • Why does the process smell?

Although BOFA systems offer filter capacity monitoring, we know that sometimes this information can get overlooked in busy workshop environments. So remember, if you can smell a process then the chances are the emissions are not being captured effectively by the filter and the carbon could be saturated. Check whether the extractor filter light is illuminated and then change the pre-filter. If it is still illuminated, change the combined filter. BOFA units with our iQ technology offer independent filter monitoring to report on the status of both the pre-filter and combined (main) filter…and will enable the timely exchange of filters.


  • Where can I buy new filters?

New filters should be purchased from the distributor who provided the BOFA equipment because they will hold precise details of your system configuration. Also, think ahead and make sure you hold sufficient stock for maintenance purposes and to avoid the possibility of unplanned downtime.


  • Why is my pre-filter blocking so quickly?

Some processes can generate large amounts of solid particulate and dust or can produce ’sticky’ particulate, which can sometimes apparently block filters ahead of their projected service lifetime. In these instances, BOFA can provide application assistance from over 30 years of experience to offer additional inline pre-filters, cyclones, or the unique Dust-Checker multi-layer bag filters to improve service life and system availability.

To find out more about filters, go to the FAQs section on our website: