By sector / Takeaways
A takeaway can have a wiped-down, tidy-looking counter and still be carrying a serious fire load out of sight. Continuous frying puts far more grease into the extraction than the daily clean ever reaches.
Small unit, heavy load
A takeaway is often a small floor area doing a disproportionate amount of frying. That combination is exactly what fills an extraction system faster than anywhere else.
Different cooking styles leave different grease. Deep frying lays down a translucent, creosote-like film; chargrilled and solid-fuel meats throw off large quantities; and an average burger sheds around nine grams of fat as it cooks. That grease bonds to the metal of the duct, then builds carbon layers on top. None of it is visible at the counter, which is the trap: the front can look spotless while the fire load sits in the ductwork above the fryers.
This is why heavy-use kitchens sit at the top of the cleaning matrix, at roughly a three-month extraction interval. The scale of the risk is not abstract: in London a commercial kitchen extraction system catches fire on average once every nine days, and kitchen ductwork fires cost UK insurers around sixty-five million pounds a year in claims.
Looks clean versus is clean
Daily cleaning by the team is essential and does real work on the surfaces and filters you can see. What it cannot do is reach the inside of the duct run and the fan, which is precisely where the heavy frying sends its grease. That gap between looking clean and being clean is the whole case for a professional deep clean in a takeaway.
Filters deserve a mention of their own. On heavy frying they clog fast, and a clogged filter drops airflow, which pushes more grease past into the duct and speeds the whole cycle up. Some operators keep a spare set to rotate through service, which buys real day-to-day control between professional cleans. It is a small habit that slows the rate at which the system loads.
A deep clean is necessary, but it is not sufficient. It removes the built grease and resets the fire load, but it does not slow the rate at which heavy frying refills the system. On this kind of use the interval is the real control: the clean buys you a safe baseline, and cleaning again before the grease climbs back is what actually keeps the risk down. A certificate on the wall is only current until the next build-up.
Questions
Heavy-use kitchens with frequent deep-frying or chargrilling sit at roughly a three-month interval. It is set by cooking intensity and hours, confirmed by grease readings, not by a fixed date.
Because the grease that matters is inside the duct run and fan, out of sight. Frying loads the extraction far faster than surfaces, so a tidy counter tells you nothing about the fire load above it.
Different styles leave different grease. Deep frying lays down a creosote-like film and solid-fuel or chargrilled meats throw off large amounts, all of which bonds to the duct and builds up quickly.
Very likely. Most food-business policies now carry an express warranty that the extraction is cleaned to standard at a stated frequency, and a claim after a fire can be refused without a valid, dated certificate.
Yes. We clean out of hours so trade is not disrupted, and leave the system and the paperwork ready for the next service.
Phoenix Duct Clean · by the numbers
We clean the full run from canopy to fan, measure the grease and leave a certificate your insurer and the EHO will want to see.