A filter choice made at canopy level can affect cleaning bills, duct hygiene and how well a kitchen performs during a busy service. When comparing ESP versus mesh filters, the key question is not simply which one captures more grease. It is where each filter sits in the extraction system, what type of cooking the kitchen does, and how reliably the equipment will be maintained.
Mesh filters are a familiar, low-cost option for commercial canopies. Electrostatic precipitators, usually called ESP units, are a more specialised filtration stage designed to remove much finer airborne grease and smoke particles. They can work well together, but they do not perform the same job and one is not automatically a substitute for the other.
ESP versus mesh filters: the practical difference
A mesh filter captures grease as contaminated air passes through layers of knitted metal mesh. Larger grease droplets strike the mesh, lose momentum and collect on the filter material. It is a simple mechanical process with no electrical connection, controls or high-voltage cell to maintain.
An ESP works differently. Air passes through an ionising section where fine particles receive an electrical charge. Those particles are then drawn towards collecting plates inside the unit. This enables an ESP to capture much smaller grease aerosols and smoke particles than a basic mesh filter can typically retain.
That distinction matters in kitchens producing sustained frying, griddling, chargrilling or wok cooking. Much of the contamination created by this equipment is not heavy, visible grease. It is fine airborne aerosol that can travel further into the ductwork if it is not controlled at source.
Mesh filtration is therefore primarily an initial grease barrier. ESP filtration is a higher-efficiency treatment stage for finer airborne contamination. In a properly considered commercial extraction layout, a primary canopy filter protects the system from larger grease deposits, while an ESP unit provides additional filtration downstream where required.
Mesh filters: simple, accessible and maintenance-dependent
For lower-duty cooking operations, mesh filters can be a practical choice. They are relatively straightforward to remove, wash and refit, and replacement filters are generally economical. A kitchen with light cooking, predictable hours and a disciplined cleaning routine may find they meet its operational needs.
Their weakness is also their simplicity. Fine grease particles can pass through the mesh and enter the plenum, fan and ductwork. Once grease reaches these areas, it becomes harder and more expensive to remove. Duct cleaning intervals may shorten, fan performance can deteriorate, and accumulated grease increases the fire load within the extraction system.
Mesh filters need frequent cleaning. Leaving them in place until airflow noticeably drops is not a maintenance plan. A loaded filter restricts airflow, making the fan work harder and reducing capture at the canopy. It can also allow grease to build up within the filter itself.
There is a further practical point for operators: not all washable filters are cleaned properly. A quick rinse does not remove baked-on grease from within the mesh. Commercial washing equipment, suitable degreasing chemicals and sufficient drying time are needed if filters are to be returned to service in good condition.
Where ESP units earn their place
ESP units are typically chosen where a kitchen needs a higher level of grease and smoke filtration than primary filters alone can provide. They are particularly relevant where the cooking load is high, where duct runs are substantial, or where discharge arrangements demand more control of visible smoke and airborne grease.
By collecting fine particles that would otherwise pass into the ductwork, an ESP can help keep downstream components cleaner. This may support better long-term system hygiene, provided the rest of the installation is correctly designed and maintained. It does not remove the need for duct cleaning, but it can reduce the volume of fine grease reaching the duct system.
An ESP installation requires more than selecting a unit that physically fits the duct. Airflow must match the unit specification, and access must be allowed for safe removal and cleaning of the cells. The electrical supply, isolator arrangement, duct transitions and service clearance all need considering before installation begins.
The collecting cells also require regular cleaning. If grease is allowed to build up on them, performance falls and electrical arcing can occur. This is why ESP filtration suits operators who are prepared to follow a defined maintenance schedule rather than those looking for a fit-and-forget solution.
Fire risk and grease management
No filter type removes the need for sensible fire-risk management. Grease is fuel, and extraction systems handling greasy cooking vapours must be designed, used and cleaned with that fact in mind.
Mesh filters can retain significant quantities of grease, especially when cooking volume is high. If cleaning is missed, that grease remains directly above the cooking line. ESP units collect grease internally on plates and cells, so they too must be cleaned thoroughly and at appropriate intervals.
The sensible approach is to think in stages. Capture grease effectively at the canopy. Prevent excessive contamination from entering the ductwork. Provide access for cleaning and inspection. Then set a routine that matches the actual cooking operation, rather than relying on a generic calendar reminder.
For commercial kitchen projects, the canopy, filter arrangement, fan selection and ductwork should be considered as one system. DW172 sets out recognised guidance for kitchen ventilation, while ductwork construction and installation must also be suitable for the duty involved. A premium-quality ESP will not correct poor canopy capture, undersized ductwork or an incorrectly selected fan.
Installation considerations that are often missed
A common mistake is treating filtration as a late addition after the canopy and duct route have already been fixed. An ESP unit takes up space, needs service access and creates resistance that the fan must overcome. If these points are ignored, the final system may fail to deliver the intended airflow at the canopy.
Filter layout should also account for kitchen operations. Staff must be able to remove canopy filters safely, without climbing, stretching across cooking appliances or disrupting service. ESP access panels and cells must be reachable for cleaning. If routine maintenance is awkward, it is far more likely to be delayed.
The material and fabrication quality of the canopy matter too. A well-built stainless steel canopy with properly formed filter housings helps filters sit correctly and prevents unwanted air bypass. Standard 430-grade stainless steel is suitable for many commercial applications, while 304-grade stainless steel can be specified where the environment or client requirement calls for increased corrosion resistance.
For bespoke schemes, a made-to-measure canopy can allow the filter bank, spigot positions and duct connections to work around the actual cooking equipment rather than forcing the kitchen into standard dimensions. CanopyMan manufactures commercial canopies in Birmingham and can build to project-specific sizes where a standard unit is not the right fit.
Which option is right for your kitchen?
Mesh filters may be sufficient where cooking is light, grease production is limited and the operator can clean filters regularly. They offer a straightforward first-line solution and are easy to replace when damaged or worn.
An ESP is worth considering where the kitchen produces substantial fine grease and smoke, where maintaining cleaner downstream ductwork is a priority, or where the extraction system needs a more advanced filtration stage. It requires a higher initial investment and more considered servicing, but it can be the more appropriate engineering choice for demanding cooking loads.
In many commercial installations, the best answer is not ESP or mesh. It is a properly designed primary filtration stage followed by ESP treatment where the cooking duty and site conditions justify it. Start with the appliances, expected hours of use, canopy dimensions, duct route and maintenance capability. That gives you a filtration specification built for the kitchen you actually operate, not just the lowest-cost item that fits the opening.
Before placing an order, map out who will clean each component, how often they will do it, and whether they can reach it safely. The right filter is the one that will still be clean, accessible and working properly six months after the kitchen opens.