Restaurant Exhaust & Rangehood Cleaning — Fire Safety Compliance
Key Points
- Restaurant exhaust and rangehood cleaning is required under AS 1851 (Australian Standard for fire protection system maintenance) — grease accumulation in exhaust systems is one of the leading causes of commercial kitchen fires in Australia.
- The complete exhaust system consists of four components requiring regular cleaning: the rangehood canopy and filters, the ductwork interior, the plenum chamber, and the exhaust fan — weekly filter cleaning alone does not satisfy the AS 1851 requirement.
- Most Melbourne restaurants require quarterly (every 3 months) AS 1851 exhaust deep cleaning — high-heat operations such as charcoal, wood-fired, and wok cooking require monthly cleaning due to higher grease accumulation rates.
- An AS 1851 compliance certificate issued by a qualified technician after each clean is required by Melbourne councils, building owners, and commercial fire insurers. Operating without current certification can void your fire insurance.
- Weekly rangehood filter cleaning (removing and degreasing the grease filters) is a separate, more frequent task that should be performed by kitchen staff or a regular cleaning contractor — it does not replace the quarterly AS 1851 deep clean.
Understanding the Difference: Filter Cleaning vs Exhaust Deep Cleaning
The most important distinction in restaurant exhaust cleaning is between weekly rangehood filter cleaning and the quarterly AS 1851 exhaust system deep clean. These are two different tasks performed at different frequencies, by different people, for different reasons — and both are required.
Weekly rangehood filter cleaning involves removing the grease baffle or mesh filters from the rangehood canopy and degreasing them — either in a commercial dishwasher with a degreasing cycle or by hand-soaking in a hot degreaser solution. This prevents filter clogging and maintains extraction airflow. It is performed by kitchen staff or a regular cleaning contractor and takes 20–40 minutes. It does not involve accessing the ductwork, plenum, or fan.
Quarterly AS 1851 exhaust deep cleaning involves accessing and cleaning the entire exhaust pathway from the canopy interior through the ductwork, plenum chamber, and exhaust fan. It requires a trained technician with specialised equipment, high-concentration alkaline degreasers, and access to parts of the system that are inaccessible during routine cleaning. It concludes with the issue of an AS 1851 compliance certificate. Weekly filter cleaning does not replace this quarterly obligation.
Critical: Many Melbourne restaurant operators believe that weekly rangehood filter cleaning satisfies their fire safety obligations. It does not. Filter cleaning maintains airflow — it does not remove the grease that has migrated past the filters into the ductwork and plenum. A restaurant with immaculately clean filters can still have a ductwork fire if the quarterly AS 1851 deep clean is not performed.
The Four Components of a Restaurant Exhaust System
Rangehood Canopy & Filters
The visible hood above cooking equipment. Contains removable grease baffle filters that capture grease vapour. Canopy interior surfaces accumulate grease on walls, ceiling, and grease collection channels. Filters: weekly clean. Canopy interior: part of quarterly deep clean.
Ductwork
The metal duct that carries grease-laden air from the canopy to the exhaust fan and exterior. Internal duct walls accumulate grease deposits that are invisible during normal operation. The primary fire risk zone — a duct fire spreads rapidly through the entire building. Deep clean required quarterly.
Plenum Chamber
The collection chamber between the ductwork and the exhaust fan. One of the highest grease accumulation points in the system — grease migrates from throughout the ductwork and collects here. Often the deepest grease deposits are found in the plenum. Deep clean required quarterly.
Exhaust Fan
The mechanical fan that drives air through the entire system. Fan blades accumulate grease that causes imbalance, reducing efficiency and increasing motor wear. Fan housing and motor exterior require degreasing. Included in quarterly deep clean — blades inspected and tested post-clean.
What an AS 1851 Exhaust Deep Clean Involves
An AS 1851-compliant exhaust deep clean is a structured procedure that must be performed by a trained technician familiar with the standard's requirements. The following outlines the process for a typical Melbourne restaurant exhaust system clean.
Cleaning Frequency by Kitchen Type
AS 1851 provides guidance on inspection and cleaning frequency based on cooking method and volume. The standard's intent is that higher-risk kitchens — those producing more grease vapour per hour — are cleaned more frequently to maintain the same level of fire risk reduction.
| Kitchen Type | Frequency | Reason |
|---|---|---|
| Charcoal grill, wood-fired oven, open flame cooking | Monthly | Carbon and polymerised grease accumulate 3–4× faster than gas cooking — ductwork can reach fire-risk grease levels within 4–6 weeks |
| High-volume wok cooking (Chinese, Thai, Korean BBQ) | Monthly to 6-weekly | Wok cooking produces extremely high grease vapour volumes — wok hei cooking at high heat generates rapid duct contamination |
| High-volume deep frying operations | Monthly to quarterly | Deep frying produces high aerosol grease — volume determines frequency |
| Standard commercial kitchen — medium volume | Quarterly | AS 1851 recommended minimum for most gas-based commercial kitchens at standard volume |
| Low-volume cooking, primarily assembly/cold prep | Bi-annual | Minimal grease vapour generation — 6-monthly may be sufficient subject to AS 1851 assessment |
| Cafes — coffee, toast, sandwiches only | Annual minimum | Very low grease vapour — annual adequate if rangehood filters cleaned weekly |
What Melbourne Councils, Insurers & Building Owners Require
The AS 1851 compliance certificate is the document that three separate parties require from Melbourne restaurant operators — and each has different consequences for non-compliance.
Melbourne councils inspect commercial kitchens under both the Building Act 1993 (VIC) and local fire safety compliance frameworks. A council inspector finding an overdue or missing AS 1851 certificate can issue a fire safety defect notice requiring immediate remediation. For restaurants in multi-tenancy buildings, the building owner or body corporate may also hold the tenant responsible for maintaining current exhaust certification.
Commercial fire insurers include exhaust system maintenance compliance as a condition of cover for commercial kitchen policies. An insurer that discovers the AS 1851 certificate was expired at the time of a kitchen fire may deny the claim on the basis of policy non-compliance. The cost of an uncovered kitchen fire claim can be catastrophic for a restaurant business.
Building owners and landlords often include exhaust system maintenance obligations in commercial leases — the tenant is contractually required to maintain the system and provide current AS 1851 certification on request. A lease breach for non-compliance can result in breach notices and repair cost recovery proceedings.
Golden Star AS 1851 exhaust cleaning for Melbourne restaurants covers all components — canopy, ductwork, plenum, and fan — with certificates accepted by all Melbourne councils and commercial insurers. Programs available on pre-booked quarterly or monthly schedules so you never need to track compliance dates yourself. Call 0484 042 336 to set up your program.
How to Maintain Your Rangehood Between Deep Cleans
Between quarterly AS 1851 deep cleans, regular maintenance of the rangehood canopy and filters reduces grease accumulation rates and extends the effectiveness of each deep clean. The following weekly and monthly tasks should be incorporated into your kitchen cleaning schedule.
Weekly — Filter cleaning: Remove all grease baffle or mesh filters. Soak in a hot degreaser solution or run through a commercial dishwasher with a degreasing cycle. Rinse and reinstall. This is the single most effective weekly maintenance task for controlling grease buildup in the broader system — clean filters allow more grease vapour to be captured at the filter stage rather than migrating into the ductwork.
Weekly — Canopy exterior wipe: Wipe the exterior and visible interior surfaces of the canopy with a kitchen-safe degreaser. This doesn't access the ductwork but reduces surface grease on the canopy walls that would otherwise migrate into the system during operation.
Monthly — Grease collection channel inspection: Check the grease collection troughs or channels at the base of the rangehood canopy. If grease levels are high, drain and clean the channels. Full grease channels overflow into the cooking area — a separate fire and food safety hazard.
Action Steps
1. Check your current AS 1851 certificate. Find your most recent AS 1851 exhaust cleaning certificate. Check the date — if it is more than 3 months old (or more than 1 month for charcoal/wok operations), your system is overdue. Book immediately.
2. Book your next four quarterly cleans at once. The most efficient approach is to pre-book all four quarterly cleans at the start of the year on a fixed schedule. Golden Star issues a reminder 2 weeks before each scheduled clean and delivers the AS 1851 certificate on the day of the clean. Call 0484 042 336 to arrange.
3. Add weekly filter cleaning to your kitchen close checklist. If filter cleaning is not already on your kitchen closing checklist, add it now. Assign it to a specific staff member — not "the closing team." Clean filters are the most cost-effective maintenance step between professional deep cleans.
4. Store all AS 1851 certificates in the kitchen. Keep a folder in the kitchen — not the office — with your last four AS 1851 certificates, your grease trap pump-out records, and your food safety cleaning records. When a council inspector or insurer assessor visits, you need to produce these immediately.
Frequently Asked Questions
Rangehood filter cleaning removes and degreasess the removable filter panels in the canopy — typically a weekly task taking 20–40 minutes that maintains airflow efficiency. An AS 1851 exhaust deep clean accesses and cleans the entire exhaust pathway — canopy interior, ductwork, plenum chamber, and exhaust fan — using specialist equipment and high-concentration chemicals. It is performed quarterly by a qualified technician and concludes with an AS 1851 compliance certificate. Filter cleaning does not replace the quarterly deep clean and does not satisfy the AS 1851 requirement.
An expired AS 1851 certificate creates three concurrent risks: council fire safety compliance exposure (a council inspector finding an expired certificate can issue a fire safety defect notice), insurance risk (a kitchen fire occurring while certification is expired may result in a denied insurance claim), and lease compliance exposure (many commercial leases require current AS 1851 certification as an ongoing tenant obligation). The immediate action is to book an AS 1851 exhaust deep clean as soon as possible and file the new certificate upon receipt. Call Golden Star on 0484 042 336 for urgent exhaust cleaning bookings across Melbourne.
No. AS 1851 exhaust cleaning must be performed by a trained and qualified technician — the certificate is only valid when issued by someone with the appropriate qualifications and training to assess the system against the AS 1851 standard. Kitchen staff cleaning the filters weekly is maintenance, not compliance. A general cleaning contractor without specialist exhaust cleaning training cannot produce a valid AS 1851 certificate. Using an unqualified cleaner and issuing an informal "clean completed" document is not an AS 1851 certificate and provides no protection for council, insurance, or lease compliance purposes.
The cost of AS 1851 exhaust cleaning depends primarily on the size and configuration of the exhaust system — a single-canopy cafe kitchen costs significantly less than a multi-canopy restaurant with long duct runs. For most standard Melbourne restaurant exhaust systems, quarterly AS 1851 deep cleaning ranges from $350–$900 per clean including the compliance certificate. Multi-canopy systems, long duct runs, and systems with limited access panels cost more. The most accurate pricing requires a site assessment — request a free quote from Golden Star for your Melbourne restaurant.
Related Guides
Need AS 1851 exhaust & rangehood deep cleaning for your Melbourne restaurant? Golden Star provides certified quarterly programs — certificates issued same day, accepted by all Melbourne councils and insurers.
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