Kitchen exhaust air must be free from grease – Kitchen exhaust must be free from pollutants, and condensation in the exhaust duct must be avoided. That is what the new standard DIN EN 16282 (Equipment for commercial kitchens – Components for ventilation in commercial kitchens) requires. Compliance with these requirements cannot be achieved with conventional grease filters, however, because they let fine residual particles escape into the exhaust system. These particles may increase the risk of fire severely when accumulating in the exhaust duct and cause odour nuisance in the area.
In response to the stipulations of the new European standard, the ventilation sector developed highly efficient grease separators based on the cyclone principle. The Swabian manufacturer of air-purifying equipment Rentschler REVEN explains the difference to conventional filters as follows: Our X-CYCLONE® separators eject grease particles by repeatedly deflecting the air flow and, in doing so, clean themselves automatically. In contrast to separators, traditional filters collect and store grease. With increasing saturation, greasy aerosols seep into the exhaust duct.
A duct-mounted separator captures any grease residues that escape into the exhaust ductwork. It is particularly recommended for kitchens with many deep fryers where much grease is used in cooking, like in Asian restaurants or in system catering. It is also highly recommended for shopping malls, where often a dozen and more extractor hoods are connected to a single exhaust duct line.
In Bettembourg, a town in Luxembourg, the Cactus Group runs a shopping mall with a super market. Several extractor hoods are installed in the fast food and restaurant area. The exhaust air is collected in a manifold duct and flows to the heat reclaimer of the air-handling unit. This configuration is susceptible to grease deposits on the heat exchanger and the fans. Following the suggestions of SCHAKO, the REVEN agency in Luxembourg, the HVAC contractor AIO (All in One Technologies) installed a duct-mounted separator in the exhaust ductwork. It is designed for an airflow rate of 5.000 m3/h and fitted with X-CYCLONE® grease separators. An automatic washing system cleans periodically the separator on both sides as well as the exhaust air plenum. When inspecting the system one year after commissioning, the inspecting personnel were surprised by the cleanliness of the outgoing air duct and the central air-handling unit. The configuration prevents grease deposits on the equipment downstream of the separator and improves fire protection in addition.
Fundamentals of DIN EN 16282: Ventilation systems are to be installed in such a manner that foreign airborne particles and humidity are evacuated.The ventilation system must be able to separate odorous matter, grease particles and gaseous substances from the exhaust air.If the exhaust air is in direct contact with building structures, it must be made sure that any negative effects on the structures are avoided and that condensation effects do not occur permanently or regularly.