KITCHEN EXHAUST – PRIMARY DISPOSABLE WOOL GREASE PRE-FILTERS – Draft Specification

 

1.GREAS PRE-FILTERS

1.1 Scope

Provide and install primary disposable natural wool grease filtration to commercial kitchen exhaust in front of baffle filters to reduce grease carryover into exhaust ductwork, exhaust fans, inter-tenancy dampers, and base-building exhaust risers.

1.2 Performance intent

The grease pre-filtration system shall:

• Act as the sole grease filtration device at the kitchen exhaust hood

• Capture grease aerosols across a broad particle size range

• Reduce grease accumulation within ductwork and exhaust fans

• Reduce fire risk associated with grease fuel load

• Reduce base-building and landlord costs associated with AS 1851 grease cleaning

• Protect shared exhaust systems and damper operation in multi-tenancy buildings

2. STANDARDS AND REFERENCES

Comply with the following, as applicable:

• AS 1668.1 – Fire and smoke control in buildings

• AS 1668.2 – The use of ventilation and airconditioning in buildings

• AS 1851 – Routine service of fire protection systems and equipment

• NCC 2022 – Section C and Section E

• Local authority and fire brigade requirements

3. PRODUCTS

3.1 Grease filtration system

Provide primary disposable natural wool grease filters, such as those manufactured by Shepherd Filters, or approved equivalent.

Filters shall be specifically designed to operate as the primary grease filtration device in commercial kitchen exhaust hoods.

3.2 Construction

• Natural wool fibre filtration media

• Multi-layer depth filtration configuration

• Media supported within a rigid frame suitable for hood installation

• Designed for single-use replacement

• Non-washable and non-reusable

• No stainless steel baffle or cartridge filters required upstream

4. PERFORMANCE REQUIREMENTS

4.1 Grease removal efficiency

As a primary filtration device, disposable wool grease filters shall achieve:

• Up to 98% grease removal efficiency by mass, based on manufacturer test data

• High efficiency capture of both coarse grease droplets and fine grease aerosols

• Significantly higher grease capture than conventional baffle filters alone

(Typical stainless steel baffle filters remove approximately 40–60% of grease by mass and are ineffective at capturing fine aerosols.)

4.2 Temperature performance

• Suitable for continuous exposure to commercial cooking exhaust air

• Wool media to exhibit self-extinguishing characteristics

• No melting, dripping, or structural collapse under normal operating conditions

4.3 Pressure drop

• Initial clean filter pressure drop typically 75–150 Pa at design airflow

• Predictable increase in pressure drop as grease loading occurs

• Filters to be replaced prior to excessive airflow restriction or fan performance degradation

5. SYSTEM CONFIGURATION

5.1 Filter arrangement

Disposable wool grease filters shall:

• Be installed directly within the exhaust hood filter tracks

• Replace conventional stainless steel baffle or cartridge filters

• Be installed to ensure full exhaust airflow passes through the wool media

• Be sealed to prevent bypass air leakage

No additional upstream grease filtration devices are required.

5.2 Multi-tenancy and base-building exhaust systems

Where kitchen exhaust systems:

• Serve multiple tenancies, or

• Discharge into shared duct risers incorporating balancing or motorised dampers

Provide primary disposable wool grease filtration to:

• Minimise grease deposition within shared ductwork

• Prevent fouling and restriction of dampers

• Maintain exhaust system airflow and fire mode operation

• Reduce landlord exposure to non-recoverable grease cleaning costs

6. INSTALLATION

6.1 General

• Install filters strictly in accordance with manufacturer’s instructions

• Ensure correct airflow orientation through the wool media

• Ensure filters are securely seated and sealed within hood assemblies

6.2 Access

• Provide safe and convenient access for routine filter replacement

• Filters shall be removable without specialist tools

7. OPERATION AND MAINTENANCE

7.1 Replacement regime

In addition to As1851 compliance, Disposable wool grease filters shall be replaced at intervals determined by cooking load, typically:

• Monthly for heavy grease-producing kitchens

• Every 2–3 months for moderate grease applications

Filters shall not be cleaned, washed, or reused.

7.2 Asset protection

Primary disposable wool grease filtration shall be recognised as:

• A preventative asset protection strategy

• A method of reducing grease accumulation subject to AS 1851 cleaning

• A mechanism to shift grease management responsibility to the tenant rather than the landlord

8. SUBMITTALS

Provide:

• Product data sheets

• Grease removal performance data

• Recommended replacement intervals

• Disposal and waste management guidance

9. WARRANTY

• Manufacturer’s warranty covering defects in materials and manufacture

• Warranty excludes misuse or operation beyond recommended replacement intervals

 

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