Why your canopy looks clean but isn't

Because the grease that matters is hidden - the visible canopy front gets wiped daily and looks clean, while the filters, plenum, ductwork and fan behind it build up grease that wiping never reaches. Your canopy can look clean but not be clean because the visible face and the hidden system are different things, cleaned separately. The visible canopy front (the surface you see and reach) gets wiped daily as part of routine cleaning, so it looks spotless. But the parts that matter - the filters (and behind them), the plenum (the space above the filters), the ductwork, and the fan - are hidden, and they build up grease as the grease-laden air passes through. Daily wiping cleans the visible surface but doesn't reach these hidden internal parts. So a clean-looking canopy front and a grease-laden hidden system can coexist. And because the fire-risk grease is in those hidden parts, a clean-looking canopy can hide a real fire risk. So 'looks clean' (the surface) isn't 'is clean' (the whole system). So because the hidden parts aren't cleaned by wiping the surface. So the grease is hidden behind the clean face. This is general guidance.

It keeps the visible canopy surface clean (good housekeeping), but it doesn't reach the hidden internal parts - filters' hidden side, plenum, ductwork and fan - where the grease and fire risk build up; only a proper clean does that. Daily cleaning keeps the visible canopy surface clean - which is good hygiene housekeeping and keeps the kitchen presentable - but it doesn't keep the whole extraction system clean. The wiping addresses the surface you can see and reach; it can't get to the hidden internal parts: the hidden side of the filters, the plenum (the space above the filters), the ductwork, and the fan. These build up grease as the grease-laden air passes through, out of sight and untouched by the daily wipe. So however diligent the daily cleaning, it keeps only the surface clean, not the hidden system. The hidden parts - where the fire-risk grease accumulates - are cleaned only by a proper, periodic extraction clean that reaches inside them. So daily cleaning and proper extraction cleaning do different jobs: the surface, and the hidden system. So no - daily cleaning does the surface, not the hidden parts. So no; only a proper clean reaches the grease. This is general guidance.

In the parts behind the visible face: the hidden side of the filters, the plenum (the space above the filters), the ductwork, and the fan - where the grease-laden air deposits grease as it passes through, out of sight. The hidden grease builds up in the internal parts of the extraction, behind and above the visible canopy face. As the grease-laden air from the cooking is drawn through the system, it deposits grease along the way in: the filters (including their hidden side); the plenum (the enclosed space above the filters, inside the canopy); the ductwork (the hidden ducts carrying the air away); and the fan. These are all out of sight from the kitchen, so the grease accumulating in them isn't visible - and isn't touched by wiping the canopy front. Crucially, this is where the fire-risk grease lives: the build-up in the plenum, ductwork and fan is what fuels duct fires. So the hidden grease is exactly in the parts that matter most for fire safety, and exactly the parts a clean-looking canopy gives no clue about. So it builds up in the filters, plenum, ductwork and fan. So in the hidden internal parts. This is general guidance.

Because the fire-risk grease is in the hidden parts - so a clean-looking canopy can mask a real, uncontrolled fire risk (and a system underperforming from grease you can't see); appearances hide the very thing that matters. A hidden grease build-up matters even when the canopy looks fine because the fire-risk grease is exactly in the hidden parts (the plenum, ductwork and fan). So a system that looks clean from the kitchen can still carry a serious, uncontrolled fire risk - the hidden grease building toward a duct fire, entirely masked by the clean-looking canopy. And the extraction can be underperforming (weak airflow, a hotter, smokier kitchen) from the hidden grease choking it, despite the clean surface. So the clean appearance hides two real problems - the fire risk and poor performance - that live where you can't see. The reassurance of a gleaming canopy is the false comfort that lets the hidden fire risk build unnoticed. So the appearance is exactly what masks the danger, which is why a clean-looking canopy can't be trusted as a sign of a safe system. So because the hidden grease is the fire risk, masked by the clean look. So the fire risk is hidden behind the clean face. This is general guidance.

Have it surveyed or inspected (which reveals the real state of the hidden parts, often surprisingly greasy) and properly cleaned to TR19 Grease - the daily canopy wipe tells you nothing about the hidden system. To know if your extraction is actually clean, you need to look at (or have someone look at) the hidden parts - not judge by the canopy's appearance. A survey or inspection by an extraction specialist reveals the real state of the hidden system (the filters' hidden side, the plenum, the ductwork and fan), which is often surprisingly greasy despite a clean-looking canopy. And a proper extraction clean (to the TR19 Grease standard, reaching the whole system) removes the hidden grease and confirms the real clean, with verification and before-and-after photographs of the internal parts. So the way to know is to have the hidden parts checked and cleaned - the daily surface wipe tells you nothing about them. This is especially worth doing if it's been a while since a proper clean, however clean the canopy looks day to day. So don't rely on appearances; have the hidden system surveyed and cleaned. So have it inspected and properly cleaned. This is general guidance.

It's good housekeeping and hygiene, but it's not evidence of a clean system - the visible surface and the hidden fire-risk parts are cleaned separately, so a clean face says nothing about the ductwork and fan behind it. A clean-looking canopy is a good sign for housekeeping and hygiene - it shows the visible kitchen surfaces are being kept clean, which matters for presentation and general cleanliness. But it's not evidence that the extraction system is clean, because the visible surface and the hidden internal parts are cleaned separately: the surface by daily wiping, the hidden parts (filters, plenum, ductwork, fan) only by a proper extraction clean. So a clean canopy face tells you the surface is clean, and nothing about the ductwork and fan behind it (where the fire-risk grease lives). So don't take a clean-looking canopy as reassurance about the system's real state or its fire safety - it's a clean surface, which is good, but not a clean system. To judge the system, look behind the face. So it's good for hygiene, but not a sign of a clean system. So it's a clean surface, not a clean system. This is general guidance.