Process & access
A number given over the phone is a guess. Grease load, duct layout and access all change the job - and none of them can be judged without a look at the actual system.
The short answer
It is a fair question: why can a cleaner not just give a price over the phone? The answer is that almost everything that decides the cost of a kitchen duct clean is hidden until someone inspects it. How much grease is in the system, how long and complex the runs are, whether there are risers to climb, and whether there is any access at all - these are the things that set the scope, and none of them can be seen down a phone line. A survey is not a sales tactic; it is the only honest basis for a real quote.
What the survey actually establishes
The first unknown is the grease load. A technician measures it in microns using a Wet Film Thickness Test or a Deposit Thickness Test, which shows how heavy the build-up is and where it is worst. A lightly loaded system verified near the fifty-micron mark is a very different job from one sitting well above the 200-micron clean trigger with 500-micron hot spots. The reading turns guesswork into scope.
The second and third unknowns are layout and access. Kitchen ductwork can be a short single canopy run or many metres of horizontal duct and vertical risers threading through a building. And it can only be cleaned where there are panels to open - TR19 Grease calls for access at a minimum of every two metres. A survey reveals whether the panels exist, whether new ones must be cut, and how the runs are reached, all of which change the work involved.
Why a blind number costs you either way
A quote given without a survey is wrong in one of two directions, and both hurt you. Priced too low, it turns into extras once the panels come off and the true grease load and access problems appear - the classic mid-job surprise. Priced too high to be safe, you are paying a padded number to cover the unknown. Either way you are being charged for a system nobody has actually looked at.
A survey removes that. It converts the job from an estimate into a scope: this much duct, this grease load, these access points, this fan. The quote that follows reflects the real system, so the figure you are given is the figure the work is built on. It also flags anything that needs sorting first, such as missing access panels, before it becomes a surprise cost halfway through the clean.
A survey is the start of the clean, not a hurdle
Seeing the duct before quoting is the same first stage that a compliant clean needs anyway - the survey. It measures the grease, maps the runs and confirms the access, and that information is what a fair quote, and later a proper clean, are both built on. Far from slowing things down, it is what stops the job going wrong.
Questions
Because the things that set the price - grease load, duct layout and access - are hidden until someone inspects the system. A phone figure is a guess that usually turns into extras or a padded number to cover the unknown.
The grease thickness in microns using a Wet Film Thickness Test or Deposit Thickness Test, the length and complexity of the runs and risers, and whether there is enough access to clean the whole system.
It is part of doing the job properly and is what a genuine quote is built on. Treating it as an optional add-on is usually a sign the clean itself may not be scoped to the whole system.
The survey will find that, and fitting compliant panels becomes part of the scope. It is far better to know before the clean than to discover mid-job that stretches of duct cannot be reached.
It varies with the size of the system, but it is short compared with the clean. The point is to inspect and measure enough to scope the work accurately, not to clean at that visit.
Phoenix Duct Clean · by the numbers
We survey the system first - grease load, layout and access - so the quote reflects the real job, with no surprises once the panels come off.