User:BrianAsh/Grease Filter

The term grease filter often refers to filters found in air exhaust systems from extractor hoods. These are commonly simple aluminum mesh filters in home extractor hood use where little oil is used in cooking. However, commercial kitchens and households that often fry in oil, may be required by Code to install baffle filters to prevent grease fire in the duct system. Other systems available include

Filter Materials: Aluminum Galvanized Steel Stainless Steel ( can be NSF certified )

"Industry standard baffle filter, suited for light duty grease applications, removing 28% of particles at 8 microns. Exhaust air passes through the aluminum/stainless steel baffles and as it is turned, the principle of inertial impaction (The principle of the particle's momentum throwing the particle out of the airflow as it changes direction, to remove grease from the airflow) goes to work. As the air turns, the particulates impact upon the baffles. The grease then runs down the baffle into the grease trough which drains into a removable grease container Tested to ASTM F2519-2005 standard method of test." • UL 1046 Listed; NSF Certified --http://www.greenheck.com/products/detail/41

Key Attributes of Grease Filters:

Face velocity (often rated in FPM feet per minute)
Gage Pressure drop (inch of water gauge (in wg or "wg)= inch of water column (in WC) traditional unit of gage pressure, used in plumbing to describe both water and gas pressures. 1 in w.g.= 249.0889 Pa, 0.036 127 PSI.)

When discussing exhaust systems efficiency can refer to either the Efficiency of exhaust system or the Efficiency of grease capture. Thus a clogging mesh filter becomes an increasingly efficient sieve of the air passing through, while it results in a decreased efficiency of the exhaust system (either requiring more fan power to maintain a flow rate, or reducing the velocity of air intake such that the plume of grease etc. is less completely drawn into the extractor hood.).

See Also: grease duct, duct (HVAC), passive fire protection (PFP), smoke exhaust ductwork, kitchen exhaust cleaning, extractor hood, fume hood, ventilation, heating, ventilation, and air conditioning (HVAC),

Relevant Standards: --Local to the USA American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) research project, 1033-RP, addressing the relationship between grease deposition and exhaust velocity

NFPA96 3-1 Grease Removal Devices in Hoods UL 1046 Grease Filters for Exhaust Ducts UL 900 Restaurant Filters

Nfpa.com (national fire protection association)

--Local to United Kingdom DW172, The HVCA specification for Kitchen Ventilation Systems http://www.hvcapublications.co.uk/Ecommerce/ID/35/Product/SpecificationforKitchenVentilationSystems/Details.aspx

--International International Mechanical Code, the International Fire Code, and the Uniform Mechanical Code.

References: PETER C. D’ANTONIO, PE. Grease Removal and Kitchen Exhaust Systems. HPAC Engineering . May 2004. Found online at http://bryanexhaust.com/blog3/2008/02/11/grease-removal-and-kitchen-exhaust-systems-2/ and at The History of Kitchen Appliances http://www.rangehoodsstore.com/articles/2010/04/grease-removal-and-kitchen-exhaust-systems/ and at http://hpac.com/ventilation-iaq/grease_removal_kitchen_exhaust/index1.html