Process & access
There is no single answer - a small single-canopy system can be a few hours, while a tall multi-storey riser run is a full shift. Five things decide which end you are at.
The short answer
The honest answer to how long a full duct clean takes is: it depends, and a good contractor tells you why rather than quoting a flat number. A compact single-canopy system with good access can be cleaned in a few hours. A large system with long horizontal runs, tall risers and heavy grease can take a full day or an overnight shift. What sets the duration is the system itself, and it is measured properly during the survey - which is one more reason the survey comes first.
What decides the time
The biggest factor is the size and shape of the system. A short run from canopy to fan is quick; many metres of horizontal ductwork, plus vertical risers passing through several floors, take far longer because every metre has to be reached and cleaned. Roof-mounted fans and rooftop discharge add time too, because working at height has to be set up safely before anyone starts.
The second factor is the grease load. A system cleaned regularly and sitting near the fifty-micron mark clears quickly; one that has been left until the grease is heavy and baked hard needs more scraping, more chemical dwell time and more passes with the brush machine. The third is access: where compliant panels already exist at the two-metre spacing TR19 calls for, the crew moves along the run efficiently; where access has to be cut and fitted first, that work is added to the day.
Roof to canopy, and around your service
A genuine full clean covers the entire route - canopy and filters, the horizontal and vertical ductwork, and the fan and discharge at the roof. That end-to-end scope is what takes the time, and it is also what separates a full clean from a quick canopy wipe that is over in an hour but leaves most of the system untouched. When someone quotes a suspiciously short time for a large system, it usually means only the easy, visible parts are being cleaned.
Timing also has to work around your kitchen. Because the system has to be off and cool for safe access, cleans are often scheduled out of hours - overnight or early morning - so the work happens while you are closed and you open on a clean, compliant system. On a very large site the clean may be phased across more than one visit. The survey is what lets a contractor give you a realistic window rather than an optimistic guess.
Time follows the system, and the survey reveals it
Because duration is driven by size, grease load and access, it can only be judged once the system has been surveyed. A contractor who has measured the grease and mapped the runs can give you a realistic window and schedule it around your trading. One who quotes a flat time sight-unseen is guessing - and usually only planning to clean the parts they can see.
Questions
Anywhere from a few hours for a small single-canopy system to a full day or overnight shift for a large system with long runs, risers and heavy grease. The survey is what pins down a realistic figure.
System size and shape, the grease load, and the amount of access. Long runs, tall risers, heavy baked grease and missing access panels all add time; a compact, well-accessed, regularly cleaned system is quick.
Yes - a full clean covers the canopy and filters, the horizontal and vertical ductwork, and the fan and discharge at the roof. That end-to-end scope is what takes the time.
A large system cannot be fully cleaned in an hour. A suspiciously short time usually means only the visible canopy is being cleaned, leaving the concealed runs untouched.
Often, yes. Because the system must be off and cool for safe access, cleans are frequently scheduled overnight or early morning so trading is not disrupted.
Phoenix Duct Clean · by the numbers
We survey first, so we can tell you honestly how long your clean will take - and schedule it around your service rather than across it.