Duct Cleanliness Testing and Condition Surveys
Independent ventilation hygiene assessors · No cleaning services
If you are not sure whether your ductwork needs cleaning, a duct cleanliness test gives you the answer before anyone sells you a cleaning programme. We inspect and test your systems, tell you what condition they are in and recommend only what the evidence supports.
Established 19992,500+ assessmentsSafeContractor approvedBOHS Affiliate MemberLondon & South East
Do I need duct cleanliness testing?
Testing is worth considering if any of these apply.
- Visible dust around grilles and diffusers
- Recurring odours when the system runs
- Staff or tenant complaints about air quality
- Construction or fit-out work nearby or inside the building
- Taking over a building or FM contract with an unknown maintenance history
- A lapse in planned maintenance or filter changes
- An insurer, landlord or auditor has asked for evidence
- Suspected poor filtration or contamination
Survey or cleaning?
Cleaning is only justified when the evidence shows it is needed. This is how we help you decide.
| Situation | Recommended first step |
|---|---|
| No recent inspection record | Condition survey with quantitative testing |
| Visible contamination or complaints | Targeted survey linked to the complaint, with IAQ testing if needed |
| Cleaning already quoted by a contractor | Independent pre-clean survey to confirm the need and scope |
| Cleaning just completed | Independent post-clean verification |
| Routine compliance evidence needed | Planned TR19 Air assessment |
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How we test
We combine inspection with the quantitative method that suits your ductwork.
- Visual inspection of accessible sections
- Photographic and, where useful, video inspection
- Deposit Thickness Testing (DTT) on suitable flat metal surfaces
- Vacuum testing (EVT) where a gravimetric result is needed or DTT is unsuitable
- Wet Film Thickness Testing (WFTT) for grease in kitchen extract systems
- Indoor air quality testing where the problem needs it
What you get
Every survey gives you a clear basis for decisions.
- Clear evidence of the condition of each system
- Defined boundaries of what was and was not surveyed
- A proportionate cleaning specification, only where needed
- An audit-ready report you can share with insurers, landlords or auditors
Limitations and what this assessment cannot tell you
Duct cleanliness testing describes surface condition at the time of the survey.
- It covers accessible sections only
- It does not by itself identify microbial contamination
- It does not measure ventilation performance
- It does not on its own diagnose an indoor air quality complaint — we combine it with IAQ testing where needed
What your report includes
- Systems surveyed and access points used
- Test method and results at each location
- Photographs linked to locations
- Condition classification against TR19 Air
- Inaccessible areas and limitations
- Recommended actions, if any, and re-test advice
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Frequently Asked Questions
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Need Indoor Air Quality Testing?
Get a no-obligation quote. We provide IAQ testing, ventilation assessment and environmental monitoring across London and the South East.