How often does a commercial kitchen exhaust need cleaning?
There is no honest single number. What sets the interval for your kitchen, and how it is checked.
AS 1851-2012. Section 13.
AS 1851-2012 is the maintenance standard for fire protection systems and equipment. Its Section 13 sets out the requirements for routine service of the fire and smoke control features of mechanical services in buildings covered by AS 1668.1, AS 1668.2, AS 1682.1, AS 1682.2 and AS 2665. A commercial kitchen’s exhaust system sits there: canopy, filters, plenum, ductwork, riser, fan and discharge.
This page does not quote the standard’s tables, and it does not state a number of cleans a year on the standard’s behalf. Read the standard itself, or ask your provider to show you the clause, before relying on any figure you are given.
Hours and grease, not the calendar.
AIRAH’s Best Practice Guide for Commercial Kitchen Exhaust Management is written to go beyond the minimum inspection and routine service requirements of AS 1851. Its approach is risk-based. It relates the minimum frequency of inspection and cleaning to the hours and style of cooking, and to evidence of grease building up in the system.
Two kitchens on the same street can need very different intervals. A café that cooks for a few hours a day and a restaurant running two long services on solid fuel do not load a duct in the same way.
An estimate, then a check.
Where there is no history to go on, such as a new system, AIRAH suggests estimating the starting interval from how much grease the cooking is expected to produce and how many hours the system runs each day. That is a starting point, not a conclusion.
Cleaning your own team does, such as wiping hoods and washing filters, is treated as additional to professional cleaning. It does not lengthen the professional interval. Your insurer may also set its own requirement, particularly for the hood and plenum. Ask, and keep the answer on file.
The reading decides.
After the first service, measured grease depth at the access points is the evidence. A reading that shows less build-up than expected can justify a longer interval. One that shows more calls for a shorter one. The interval is a professional recommendation from what was measured. It is not a figure the standard hands you.
Measured, written down.
Summit measures grease depth at every access point opened, photographs each position, records anything it could not reach and why, and writes the recommended interval on the certificate. The next service is set before the team leaves. A site survey is the first step: it sets the interval from your measured system.
Four questions
worth asking anyone.
What do you measure, and where?
Ask for the readings, position by position, not a statement that the system is clean.
Can I see before and after photographs?
From the same positions, so the two can be compared.
Was the whole system serviced?
The report should say whether it was the whole system or only part, and what was not reached.
How was my interval set?
And what evidence would change it, in either direction.
Get your interval set and documented.
A site survey sets the interval from the measured system and puts the evidence chain in place from the first visit.
enquiries@summitam.au