Check for any open pores or gaps and air leaks in the system. If there are any leaks in the positive pressure side then it may bring in the pollutants and contaminated air inside which can also result in poor absorption of exhaust air. The air transport acceleration must be adequate to ensure that all air pollutants are captured and returned to the filter.
The ducts should ideally be straight with few or no twists to reduce air resistance and ensure adequate circulation of air. Ensure that you have high-quality equipment, such as strong wiring, non-combustible and zinc coated duct construction, and adequate wire grounding.
Keep in mind the hood is at a convenient height for clean up and filter replacement. The air filters should not be used as an ignition source. It must be impervious to contamination, corrosion and abrasion damage. The release area, or the region whereby airflow reaches and exits the kitchen, must be given top priority in terms of both design and location.
Kitchen design, roof enclosure, and the size of adjacent structures must all be considered because they can have a direct impact on negative air pressure.
Centrifugal Collectors: a centrifugal collector separates impurities from the exhaust stream and transfers them outdoors using a quick spin action similar to that of a cyclone.
Electrostatic Precipitators: Electrostatic precipitators are used to remove tiny airborne particles by passing an electric current charge to them. Unlike centrifugal collectors, it effectively eliminates impurities from air or vapours in the kitchen.
With a regular preventive maintenance and self service of some of the parts you can ensure that the efficiency of the system does not degrade and can provide you with fresh and filtered air.