Phoenix Journal · Ductwork
Three quotes for the same kitchen extract system can differ by hundreds of pounds - because they are quietly pricing three different jobs. Here is how to line them up fairly.
Case postmortem
Three quotes for the same extract system landed in one morning - £480, £790 and £1,140 - and the manager did the sensible-looking thing and booked the cheapest.
The cleaner turned up, dropped the canopy filters, degreased the hood, wiped down the visible plenum and left a smart-looking certificate on the pass. Everyone was happy. The kitchen looked clean, the invoice was low, and the folder for the insurance file had a fresh bit of paper in it.
Six months later a small flare-up in the ductwork brought a loss adjuster on site. The first question was simple: can you show the whole system was cleaned and verified to the recognised standard? The certificate covered the canopy and filters. It said nothing about the horizontal duct run above the ceiling, nothing about the riser, nothing about the fan. There were no access panels to reach most of it, no grease readings, and no before-and-after photographs. The paperwork proved the easy 10 per cent had been done and the risky 90 per cent had been left alone.
That is the trap. The £480 quote was not cheaper for the same work - it was priced against a smaller job, and nobody spelled that out.
Nothing was dishonest, exactly. The problem was that the three quotes were never comparable in the first place, and the format hid it.
Grease fires do not start at the filters. They start and spread in the ductwork - the long, hidden horizontal and vertical runs where warm grease-laden air condenses and builds a film that behaves like fuel. The recognised UK specification for managing that risk is TR19 Grease, published by the Building Engineering Services Association (BESA). It is the document your insurer's wording almost certainly leans on, and it is explicit that the whole system, from canopy to fan discharge, is what needs to be cleaned and evidenced - not just the parts you can see from the kitchen floor.
The cheap quote quietly scoped itself down to the visible bits. It assumed the ceiling void was "not accessible" and left it, rather than pricing the access panels needed to reach it. It skipped the grease measurement, so there was no way to prove the surfaces were actually clean afterwards. And the certificate used confident language that read like full compliance while covering a fraction of the system.
When three quotes each describe their scope differently - or barely describe it at all - the only number you can compare is the price. So price wins, and the buyer ends up choosing the firm that promised to do the least. That is comparing apples to oranges and paying for the smaller fruit.
You do not need to become a ventilation engineer to compare fairly. You need to force every quote onto the same page by insisting each one answers an identical checklist. Send the same brief to everyone, and any firm that will not answer plainly has told you something useful.
With the checklist answered, the £480 quote and the £790 quote often turn out to be the same firm quoting two halves of one job - or two firms quoting two genuinely different jobs. That is the moment the comparison becomes real. A higher figure that includes fitting access panels, measuring grease deposits and issuing a full verification report can be far better value than a low figure that leaves the dangerous ductwork untouched and hands you a certificate that will not survive a claim.
Frequency is part of the sum too. A kitchen running twelve to sixteen hours a day is expected to be cleaned roughly every three months; moderate use every six; light use every twelve. If one quote assumes an annual visit and another builds in quarterly cleans, you are again looking at different products, not different prices. Nail down the interval that matches your hours before you weigh the cost, and if closing the kitchen for the work worries you, it is worth asking how firms handle deep cleans without shutting the room down so trade is not the deciding factor.
The reassuring part is that this checklist does the sorting for you. You are not judging who sounds most confident on the phone. You are judging who will put scope, access, measurement and evidence in writing - and who quietly will not.
Ask each firm one plain question: if a loss adjuster asked you tomorrow to prove this system was cleaned to standard, what exactly would I be able to hand them? A confident firm will describe the report, the grease readings and the photographs without hesitation, because producing that evidence is the job. A firm that talks only about how good the kitchen will look is telling you where its work stops.
Comparing quotes fairly is not about being suspicious of tradespeople. It is about making sure the three prices in front of you are three answers to the same question. Get the scope, access and verification onto every quote, and the apples-to-oranges problem simply disappears - along with the risk of paying a bargain price for a certificate that protects no one.
Questions
A low price usually reflects a smaller scope, not better value. Cheap quotes tend to cover only the canopy and filters and leave the hidden ductwork, where grease fires actually spread, untouched. If a fire or an insurance claim follows, a certificate that does not cover the whole system to TR19 Grease may be worthless, and you pay again to have the job done properly.
It should list the systems cleaned, the pre-clean and post-clean grease measurements, before-and-after photographs taken from the same positions, any additional works carried out, COSHH data on the chemicals used, and a recommended date for the next clean. Together with a dated certificate naming your site, this is the evidence your insurer will expect to see. A generic certificate with none of this detail is a warning sign.
Ask for the scope broken down into canopy and filters, plenum, the horizontal and vertical duct runs, any riser and the extract fan. Also check the quote addresses access, since TR19 Grease expects panels at roughly two-metre intervals so the full run can be reached and cleaned. If access is not mentioned, the hidden ductwork is probably being skipped.
Phoenix Duct Clean · by the numbers
Phoenix surveys and cleans kitchen and building ductwork to the TR19 standard - measured, cleaned and certificated, UK-wide.