How to optimize BOFA LEV filtration performance

One of the most frequent questions posed to the BOFA help desk is how to optimize the performance, capacity, and longevity of filters in our local exhaust ventilation (LEV) systems.

The saturation point at which filters need to be exchanged will largely be determined by the volume, size, and composition of the fume emitted during any given process. The question for operations managers is how best to maintain their LEV system in optimal condition to optimize extraction performance, energy efficiency and filter capacity.

How to monitor LEV performance

BOFA tailors each system to deliver the required extraction performance – and tests and inspects every unit before despatch through its rigorous 8-stage SureCHECK program that verifies fabrication, electrical components and filtration effectiveness.

Once installed, we make it easy for operators to view their extraction system performance in real time, particularly for those units featuring the Intelligent Operating system (iQ).

BOFA’s visual read-outs convey instantaneous operating information covering temperature, motor status, airflow rates (actual vs target set point) and filter condition. This makes monitoring filter saturation levels simple and helps users schedule filter exchanges in step with maintenance plans. iQ also stores downloadable historical performance data that tracks filter lifecycles and shows the effect of any changes to production and maintenance regimes.

“Should filter life decline, the first check should be focused on the process,” says BOFA Product Support Engineer Connor Barnard. “Has this changed in any way since installation…for example are different materials being worked? This can impact both the volume and composition of emissions and can potentially saturate filters more quickly. So best to contact BOFA’s technical team if you are considering a process change.”

Simple tips to maximize filter life

Regular inspection and simple maintenance can also help keep units in optimal condition and safeguard filter performance by keeping inlets and outlets free from debris. Units should never be run with a blocked filter or obstructed inlets/outlets.

BOFA’s user manuals contain useful hints and tips for maximizing filter life, cleaning the unit and replacing filters, but we recommend the ‘good housekeeping’ steps below.


  1. Daily inspection

Inspect the process to ensure extraction devices/nozzles/enclosures/hoses are in place and correctly positioned. Examine the extractor to ensure it is running and there are no alarms.


  1. Weekly Inspection

This supervisor-led inspection should look at the physical condition of extraction devices/nozzles/enclosures/hoses and check the system for damage, changes (parts added or removed) and correct operation.


  1. Monthly Inspection

Disconnect hoses and check for blockages, and signs of dust or vapor/gas/odor carry over. Check the smooth operation of the fan. Appropriate PPE should be worn.


  1. Yearly Inspection

An annual service is recommended to include these regular checks plus inspection of filter condition, extractor motor and electrics. The cooling inlets and outlets should be cleaned to prevent the build-up of dust and possible overheating of the unit. Replace any filters not exchanged during the preceding 12 months (part numbers for replacement filters can be found on the filters fitted in your system). The capture and duct velocities should be measured to ensure they are correct and haven’t changed since installation.

Please note that only trained maintenance technicians are authorized to carry out component testing and replacement. Unauthorized work or the use of unauthorized replacement filters may result in damage to the extractor unit and will invalidate the manufacturer’s warranty.

Please also check whether local regulations require a period-based LEV system test. This needs to be completed by an approved competent engineer (like BOFA’s), who will check the effectiveness of LEV systems and assess airflow, pressure and control compared to the original commissioning report. This will include a filter condition and replacement record. A certificate of compliance will be issued for each LEV system and the test data stored for a minimum of five years.

For help and advice on your filtration performance, speak to a member of our team via our LiveChat service.