Fire suppression & interlocks
A drop test is the check that a fire damper still does its one job - fully closing and sealing when its trigger releases. You release the link, watch the blades drop shut, confirm the seal, then reset and record it. In a kitchen environment it is needed more often than in most buildings.
The short answer
A drop test is the check that a fire damper still does its one job - fully closing and sealing when its trigger releases. You release the link, watch the blades drop shut, confirm the seal, then reset and record it. In a kitchen environment it is needed more often than in most buildings.
The detail
A fire damper spends its life held open, so the only way to know it still works is to make it close. The engineer accesses the damper through the access panels either side, releases the fusible link or trips the motorised actuator, and watches whether the blades travel fully shut and seal against the frame.
Closing part-way is a fail. A damper that sticks, binds or only partly closes will not hold fire back, so the result is pass or fail on full closure and seal, not on movement alone. The engineer then re-sets the blades, replaces the link if it was cut, re-secures the assembly and confirms it is back in its normal open state.
Every test is logged: the damper location and reference, its condition, the result, and any remedial action needed. That record is what demonstrates the dampers are being kept in efficient working order, as the Regulatory Reform (Fire Safety) Order requires of the responsible person.
Access is the practical make-or-break. TR19 and DW/145 call for quick-release access panels either side of the damper; without them a proper drop test is not possible. On a new installation, the first commissioning drop test should be done within a year.
What it means for you
BS 9999 sets at least annual testing by a competent person as the baseline, stepping up to more frequent - typically six-monthly - testing in dust or grease-laden environments. A commercial kitchen area is exactly that kind of environment, so the higher frequency usually applies to any dampers serving it.
Grease is why. A damper in or near greasy air can gum up between tests, and a grease-jammed damper simply fails the drop - the blades cannot close against the deposit. Cleaning and drop testing therefore dovetail: the cleaner the environment, the more likely the damper passes.
After any alteration to the ductwork, building layout or fire strategy, the affected dampers should be re-tested rather than left on the annual cycle. The test is cheap; a damper that silently stopped working is not.
The service behind the guide
Sibling guides
Why nozzles need a clean canopy · Filter condition and fire spread · Pub kitchen extraction cleaning
Questions
It is releasing the damper's trigger to confirm the blades fully close and seal, then resetting and logging it. Full closure and seal is the pass; partial closure is a fail, because a damper that does not seal cannot hold fire back.
BS 9999 sets at least annual testing, rising to typically six-monthly in dust or grease-laden areas such as a commercial kitchen. The commissioning drop test should be within a year of installation, and re-tests follow any alteration.
Commonly because it has jammed - and in a kitchen area, grease is a frequent cause. A damper gummed with deposit cannot close fully, so it fails. Keeping the environment clean is part of keeping dampers testable.
Yes. TR19 and DW/145 call for quick-release access panels either side so the engineer can reach, release, reset and inspect the damper. Without proper access a valid drop test cannot be carried out.
The building's responsible person, to show the dampers are kept in efficient working order under the fire safety order. Each record notes the damper reference, condition, result and any remedial work.
Phoenix Duct Clean · by the numbers
Phoenix Duct Clean degreases the kitchen extract and surrounds so dampers and their access panels stay serviceable and pass their drop tests.