Case Study

Bespoke Bag Filters for a Professional Finish

The Requirement

The client approached Bob Martin for a solution at a site which needed a clean air feed.  The requirement was for an air feed into the manufacturing process, to eliminate atmospheric dirt and particles.

Plans were in place for the fan, and a clean air intake housing was required.  The requirement was for two units to handle 7500 m3/hr each.


Approach A

For this application, G4 Pleated Panels would provide reasonable efficiency and dust-collecting at a low cost.  

Approach B

M5 bag filters, however, provide better dust holding and a higher efficiency, with a longer life.

We agreed with the client that bag filters would be the better choice, affording more surface area – trapping more particles without compromising the pressure loss.

The Solution

Bag filter for fine filtration in heating & ventilating and air conditioning systems, with Corrosion-resistant galvanized metal header frame, standard size with 492 x 492mm face.

The solution was for a side access housing, to be bolted on to a 50mm drilled flange on the inlet silencer, presenting a neat face of four 4 equally sized bag filters of 492 x 492mm face. Air quality to M5 efficiency was agreed, so we specified M5 synthetic bag filters. Consideration was given to the final appearance, and detail for marrying up to existing equipment. The flange was predrilled to match the drill pattern on the intake flange on the fresh air intake silencer.


We designed and costed the housing, with the final modification of replacing the flange on the front air inlet with an air intake finger grill. The housings were supplied and fitted to schedule, providing a bespoke solution with a professional finish, allowing the site to avoid contamination of the product in the manufacturing process.

Our customer said

This is an application where we needed to maximise the bag filter surface area. The application restricted us to a specific inlet face dimension of 1m x 1m. We considered using 1 full size and two half size bags but this would mean having a blanking plate of 50mm on each side.

With their bespoke manufacturing service Southern Filters were able to fully utilise the 1mx1m area and completely fill the space with 4 filter bags that require no blanking plates. This in our opinion gives a far more professional look to the installation and a made to measure appearance. The installation was completed on time and to specification.”

(Steve, MD)