Guide - TR19 Grease - UK-Wide
Searing heat and oil-rich cooking put more grease into a duct, faster, than any other style. Here is why wok and tandoor kitchens load so quickly - and how the measured interval is set.
The short answer
Wok and tandoor cooking sit at the top of the grease scale. The combination of fierce heat, aerosolised oil and continuous output means these kitchens often need cleaning inside the standard heavy-use band - sometimes in weeks rather than months:
The three-month "heavy use" figure is a starting point for a busy kitchen. A genuine high-volume wok or tandoor operation frequently measures past the 200-micron mean well before that, which is why these systems are surveyed and set on their own tighter interval.
Why so fast
The physics of these cooking styles is what drives the grease load:
How to set it
Because these kitchens load so fast, guessing the interval is riskier than usual - a generic quarterly contract can leave a high-output wok line past the safe limit for a month or more. The reliable approach is the measured one: a survey reads the grease deposit in microns through the system, and from the daily accumulation rate we set an interval that keeps the mean below 200 microns between cleans. For a genuinely heavy wok or tandoor operation that can mean cleaning every four to eight weeks rather than every three months.
Filtration matters more here too. Good baffle filters strip a lot of grease at the canopy before it reaches the duct, and keeping them in good order - the right type, not warped or missing - slows the load on the system behind them. But filters are the first line, not the whole defence: the ductwork and fan still need cleaning on the measured interval, because the fine aerosol gets past every filter eventually.
Why it matters
The kitchens that load grease quickest are, by definition, the ones whose ducts reach a dangerous fuel level soonest. High heat is already present at the cookline; a heavily greased duct above it is the fuel path that turns a wok flare or a tandoor flame into something that travels. The reason wok and tandoor systems are cleaned more often is not fussiness - it is that the fire risk in them climbs faster than in any other kind of kitchen.
Cleaning to the measured interval keeps that risk inside safe limits, keeps the system pulling air properly so the kitchen stays workable, and gives you the dated certificate your insurer and fire risk assessor expect from a high-grease operation. For these kitchens, a tighter schedule is simply the cost of the cooking - and a fraction of the cost of getting it wrong.
Questions
Searing heat aerosolises oil into a fine mist that travels deep into the ductwork, the output is continuous, and tandoors bake hard carbonised deposits onto duct surfaces. Together that loads grease far faster than lower-heat cooking, so the system reaches the safe limit sooner.
Often inside the standard three-month heavy-use band - sometimes every four to eight weeks for a high-output line. The exact interval comes from a survey that measures the grease load and sets a frequency keeping the mean below 200 microns between cleans.
Filters help by stripping grease at the canopy, so keeping the right baffle filters in good order slows the load downstream. But fine aerosol gets past every filter eventually, so the ductwork and fan still have to be cleaned on the measured interval - filters are the first line, not the whole defence.
The radiant heat of a tandoor bakes grease and smoke residue into hard, carbon-like deposits that ordinary wiping will not shift, and they get tougher the longer they are left. Cleaning on a tighter interval stops deposits reaching that baked-on state.
Yes. We work overnight, early mornings or on closing days at no extra charge for out-of-hours work, so a high-grease kitchen can stay on a tight cleaning interval without losing a service.
Phoenix Duct Clean · by the numbers
Wok and tandoor systems load fast and need a measured schedule. We survey the grease, set the interval and degrease the whole system to TR19 Grease. No-obligation quote, UK-wide.