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Commercial Kitchen Mechanical Ventilation Code (Code 2) (D&E) Adopted: Amended: * Ord 17/10/94 Responsible Division: Development & Environment Services Contents 1 2 3 4 5 6 7 8 9 10 General Kitchen Exhaust Systems Exhaust System Design - Objective Exhaust hood Design Specifications Canopy Exhaust Air Extrac5tion Rates Exhaust Canopy Make-up Air Comfort Considerations Combination of Exhaust Systems Kitchen Hood/Canopy Exhaust Ducts Kitchen Exhaust Hood Discharge Points 1. General 1.1 This standard shall apply to all new and existing commercial kitchens within the Hastings Local Government area. 1.2 All plans and specifications relating to commercial kitchen mechanical ventilation are to be approved by Council prior to installation. 1.3 This standard shall be read in conjunction with Australian Standard 1668, Part 2 1980, Mechanical Ventilation and Air Conditioning Code and Part F4 of the Building Code of Australia. 2. Kitchen Exhaust Systems 2.1 Kitchen exhaust systems are required for applications likely to generate grease vapour and also single heating devices which have a total maximum power input of 8kw, or more than one (1) item of equipment within a room having a total maximum power input exceeding 0.5kw/m3. Examples of commercial equipment power inputs are provided in Table 1. 2.2 Notwithstanding clause 2.1 above, a mechanical exhaust system may be required where Council is of the opinion that such system is necessary. 3. Exhaust System Design - Objective 3.1 Effective designing should provide effective extraction of grease, moisture and heat laden air from the surface of cooking appliances, in a nuisance free and safe manner. 4. Exhaust Hood Design Specifications 4.1 General Requirements 4.1.1 Kitchen exhaust hoods are to be manufactured from rigid impervious hard faced and non-combustible material, eg. steel, stainless steel, aluminium, with liquid-tight seams and joints made by: - butt-welding; or lapping, riveting and soldering; or any other approved method. 4.1.2 The distance between the lowest edge of a grease filter and the heat source shall be not less than: 1. For charcoal and similar types of open fires: mm 1350 2. Where the heat source is provided by a naked fire (eg. gas operated equipment): 1050 Where the heat is provided by electrically operated equipment: 600 mm 3. mm 4.1.3 All internal surfaces of hoods shall be vertical or sloped at an angle not greater than 40 degrees from vertical, unless specific approval is obtained from Council; the faces of filters shall be vertical or sloped at an angle not greater than 30 degrees from vertical. 4.1.4 Grease gutters shall be provided/located beneath any protruding surfaces or edges. Grease gutters shall be provided around the lower edges of hoods and shall include plugged drainage holes, as specified by Council. 4.1.5 All hoods shall be fitted with approved grease filters, mounted in frames in positions that enable convenient removal and replacement and be installed so as to prevent significant leakage of air around the filters. 4.1.6 A label engraved "Clean Filters at Least Monthly" is to be displayed in a prominent location/position. 4.1.7 All filters shall be located in positions of easy access and shall be so fitted as to be easily detached by hand, without tools, for cleaning and maintenance purposes. 4.2 Canopy-Type Hoods 4.2.1 The lower edge of a canopy-type exhaust hood shall be not less than 2000 mm above floor level. 4.2.2 The inside edge of the grease gutter shall be not less than 150 mm beyond the plan perimeter of the appliance over which the hood is installed, except on sides adjoining a wall. 5. Canopy Exhaust Air Extraction Rates 5.1 The following minimum standards for air extraction velocities apply: Wall Canopy Velocity m/s .5 Island Canopy .5 Flare Cooking 1 Heat Only Appliances .3 5.2 Notwithstanding clause 5.1 above, where appropriate design considerations and calculations (in accordance with Appendix C - Australian Standard 1668, Part 2 Mechanical Ventilation & Air Conditioning Code) can be demonstrated, the minimum air extraction velocities acceptable may be varied by Council. 6. Exhaust Canopy Make-up Air 6.1 The air exhausted from kitchen enclosures shall be continuously replenished by make-up air of an approved quality from an adjacent enclosure or outside the building. Where desired, or where make-up air is not available or of an approved quality, a supply air ventilation system shall be provided. 6.2 The volume of air supply is to be calculated to achieve between 85% and 90% replenishment of the exhausted volume. 6.3 Where it is proposed to obtain make-up air from an adjacent enclosure which is serviced by a supply ventilation system, the fresh air flow-rate to this supply system shall be increased by the amount of make-up air required to replenish the exhaust ventilation system. 6.4 Where the make-up air is drawn from outside the building, the intakes shall be so located and arranged that under all conditions of normal operation: (a) Contamination from air exhausts, work processes or other adjacent sources of pollution does not reduce the quality of outdoor air entering the fresh air intake to a quality below that of outdoor air in the locality, except where the outdoor air entering the fresh air intake is treated to achieve the same effect. (b) The effects of wind, adjacent structures and other factors do not cause the volumetric flow-rate of fresh air to be reduced below the minimum requirements, as specified by Clause 3.4 AS 1668, Part 2 - Mechanical Ventilation and Air Conditioning Code. Note: Treatment of the outside air supply may need to be considered so as to avoid discomfort to the inhabitants of the kitchen. 7. Comfort Considerations 7.1 Kitchen areas which do not have separate air conditioning systems or inadequate provisions for natural ventilation, must be serviced by an exhaust air system (minimum extraction rate of 5L/m2). This system must be operational during all times which the kitchen is occupied, regardless of whether cooking is occurring. 7.2 Where an exhaust air system is required to be installed as a result of Clause 7.1, a make-up air supply system complying with Part (6) is to be provided. 7.3 The extended use of exhaust canopies, during times other then when cooking is occurring, in order to satisfy the requirements of Clause 7.1, may be considered by Council. 8. Combination of Exhaust Systems 8.1 Exhaust air systems which serve different types of enclosures shall be kept separate, except where otherwise approved. 9. Kitchen Hood/Canopy Exhaust Ducts 9.1 Design and Construction 9.1.1 The design and construction of kitchen exhaust ducts is to be in accordance with Section 4, AS 1668 - Part 1, Mechanical Ventilation and Air Conditioning Code. 9.2 Installation 9.2.1 Kitchen hood/canopy exhaust ducts shall normally be installed vertically, however where this is not possible, horizontal ducts may be used, however their length should be kept to a minimum and they shall be installed with a rise in the direction of airflow of not less than 0.5%. 9.2.2. Approved access devices, large enough to enable cleaning of ducts, shall be provided at each change in direction of ducting and in horizontal duct runs at intervals not greater than 3000 mm. 9.2.3 A grease drain shall be provided at the lowest point of each run of ducting. 9.2.4 The fire protection/integrity of ducting is to be in accordance with Section 4, AS 1668 - Part 1, Mechanical Ventilation and the Building Code of Australia. 9.2.5 All exhaust ducting is to be located within the building. External ducting is not permitted, unlessapproved specifically by the Director of Development & Environment. 10. Kitchen Exhasut Hood Discharge Points 10.1 Discharge points shall be at least six (6) metres from the property boundaries, unless otherwise approved by Council. 10.2 Exhaust air shall be discharged vertically upwards from above the highest roof level at a minimum velocity of 5m/sec. 10.3 The point of discharge shall be at least 1 metre above the ridge of a pitched roof or 3 metres above a flat roof. 10.4 Notwithstanding Clause 10.3 above, Council may approve a discharge at a lower level, provided that it is located not closer than 15 metres from any adjacent higher structure located on the site and Council is satisfied that the lowering of the discharge will not create any nuisances. 10.5 Discharge points shall be at least 6 metres from any fresh air intake points of adjoining ventilation apparatus to prevent short-circuiting of air. 10.6 Council will not allow the discharge of obnoxious effluents where noise or odour nuisances may be experienced. TABLE 1 APPLIANCE Deep Fryer (counter top) Griddle Commercial Oven Half size convection oven Bake Ovens (Bakery) HEAT INPUT (KW) 12-16 3-24 28 6-10 6-22 per oven Steamers 1-18 Char Broiler Hot Dog Machine Stock Pots Tilting Kettles 2-9 1-2 5-12 12-27 APPLIANCE Deep Fryer (floor mounted) Sandwich Grill Food Warmer Pizza Ovens Electric Range (heavy duty) Vegetable Steamers (counter) Heavy Duty Electric Broiler Bratt Pans Cyclone Steamers - HEAT INPUT (KW) 14-21 8 1 8.5 - 15 per oven 6-27 1-8 12-40 18 18-50 Note: Table 1 represents the range of power inputs that may be encountered and is only a generalised guide. The power input requirement for individual appliances should be clarified prior to purchase.