Gas information sheet 62: Clearances to overhead filters and acceptable means to comply
This gas information sheet provides information about how to measure and achieve compliant clearances between commercial catering appliances and grease filters installed in extraction canopies. It also provides guidance about acceptable means to comply.
Clearances provide a safe buffer between open flame cooking appliances that can flare up during the cooking process and ignite grease-laden filters. In order to achieve compliance industry needs to understand how a measurement is to be taken between commercial catering appliances and grease filters.
It has been common Industry practice for the measurement to be taken vertically from the top of the cooking surface area to the bottom of the grease filter when measuring for the above clearances.
It has not been industry practice to protect grease filters which are not located directly above the appliance.
Industry has adopted solutions when faced with a lack of clearance between overhead grease filters and appliances, but these solutions may adversely affect the overhead canopy’s operation.
Industry adopted solutions
Industry has adopted solutions when faced with a lack of clearance between overhead grease filters and appliances. The solutions ESV will consider may involve one of the following options:
- Consult with the appliance manufacturer for optional components that may lower the appliance height and provide the required clearance between any part of the grease filter and the appliance’s cooking surface. (The optional components must be certified for use with that appliance.)
- Re-position the canopy to provide the required clearance between any part of the grease filter and the cooking surface of the appliance.
- If re-positioning of the canopy is not possible, then modify or relocate the grease filter to achieve the minimum clearance, or cover a section of the grease filter/s in the exclusion area with a permanent deflector / metal blanking plate (or shield) fixed to the canopy.
There are several important points to remember:
- Canopy modifications can only be carried out by a person authorised by the canopy manufacturer or by the installer (which may be the licensed plumber).
- Any modification must be permanent. This means the canopy cannot be returned to its original non-compliant state by cleaning or exchanging filters.
- If a new canopy is being installed and compliance option 3 (above) is being implemented, then the applicant must provide a letter specific to the installation address from the canopy manufacturer or a suitably qualified person (for example, a person authorised by the canopy manufacturer to install, commission, or modify the canopy to the manufacturer’s design).
The letter must:
- declare that the modification has not affected the canopy’s compliance with the Australian standard (AS 1668) for the approval of extraction canopies in commercial kitchens
- be on the canopy manufacturer’s or suitably qualified person’s letterhead
- be submitted as part of a new gas application, or as supporting documentation to resolve a non-compliant installation.
No letter is required for existing canopies however any modifications from existing should be done with consideration to the required performance of the canopy.
The specific wording in AS/NZS 5601.1 Clause 22.214.171.124 is not limited to grease filters located directly above the commercial catering appliance but rather incorporates any part of any grease filter which is within the minimum required exclusion area.
Therefore the measurement is to be taken on a radius measured from the cooking surface to the grease filter above and incorporating any grease filters located to each side (in an arc).
In the example provided we have a chargriller located beneath grease filters which also service other commercial catering equipment. The measurement from the chargriller to the grease filter is taken from directly above to ensure the minimum clearance of 1350 mm is met, but in addition the measurement is taken both to the left and right of the appliance to ensure the minimum clearance is not breached by adjacent grease filters. The area of grease filters within the red arc drawn in this example fails to meet the required minimum clearances.
Note: The installation of a Salamander appliance within the measurement zone is deemed compliant, unless the manufacturers’ installation instructions state otherwise.
Diagram 1: Measurement of clearances
For further information contact Gas Safety Technical Information on 1800 652 563 and select option 3 or email firstname.lastname@example.org.