Ventilation Compliance Knowledge Centre
Plain guidance on the standards, duties and evidence behind ventilation hygiene — written for facilities managers, estates teams and responsible persons.
- TR19
- Standards explained
- Marine
- Offshore & drydock
- Evidence
- What auditors expect
- Sector
- Specific guidance
Start with the essentials
The questions we are asked most often, answered in detail on the pages below.
TR19 ventilation hygiene explained
What TR19 and TR19 Grease actually require, how cleanliness is measured, and what a defensible evidence pack contains.
Marine & offshoreVentilation hygiene on vessels and offshore installations
How galley, laundry and accommodation HVAC cleaning is planned around drydock and planned maintenance windows.
ReportingWhat a compliant ductwork cleaning report looks like
The structure auditors and insurers expect: asset references, measured verification, schematics and declared limitations.
KitchensHow often should kitchen extract be cleaned?
Setting grease cleaning frequency by usage, and the evidence insurers typically ask for at renewal.
IndustryWhen extraction failure stops production
Diagnosing degraded capture velocity, locating blockages and restoring LEV performance without stripping whole systems.
HealthcareVentilation works inside live clinical environments
How duct cleaning is planned with estates and infection prevention and control teams.
Guidance library
Plain-English answers on standards, frequency, method and evidence.
Ductwork vs duct work: is there a difference?
It is a small question that comes up surprisingly often on tender documents and specifications. Here is the straightforward answer, and why it occasionally matters.
Deduct Ltd technical team · Published · Last updated
FundamentalsHow do air ducts work?
Ductwork is one of the least visible and most consequential systems in a commercial building. This is how it actually works, and where performance is usually lost.
Deduct Ltd technical team · Published · Last updated
StandardsTR19 explained: what the guidance actually covers
TR19 is referenced constantly and understood inconsistently. Here is what it is, what it is not, and what it asks of you.
Deduct Ltd technical team · Published · Last updated
ComplianceWhat are the legal requirements for duct cleaning?
There is no single law that says "clean your ducts every twelve months". There are several duties that, taken together, make inspection, cleaning and documentation unavoidable.
Deduct Ltd technical team · Published · Last updated
ComplianceCompliance in commercial duct cleaning: what evidence is worth
Most buildings that fail a ventilation compliance check have been cleaned. The problem is almost always the evidence, not the cleaning.
Deduct Ltd technical team · Published · Last updated
Fire safetyGrease build-up and kitchen fire safety
Grease deposits inside extract ductwork are combustible, concealed and cumulative. That combination is why kitchen extract cleaning is a fire safety duty rather than a housekeeping task.
Deduct Ltd technical team · Published · Last updated
KitchensThe importance of kitchen extract cleaning
Kitchen extract cleaning is usually justified on fire safety alone, but there are four separate reasons it earns its place in the maintenance budget.
Deduct Ltd technical team · Published · Last updated
KitchensKitchen extraction cleaning: health and safety considerations
Kitchen extract cleaning involves electrical isolation, working at height, confined spaces, chemicals and a food production environment. The controls matter as much as the result.
Deduct Ltd technical team · Published · Last updated
LEVLEV cleaning and testing: how the two duties fit together
LEV thorough examination and testing is a statutory duty. LEV cleaning is not the same thing — but neglecting it is the most common reason systems fail examination.
Deduct Ltd technical team · Published · Last updated
PlanningHow often is duct cleaning required?
The honest answer is that it depends on the system, and any contractor who quotes a frequency before surveying is guessing.
Deduct Ltd technical team · Published · Last updated
MethodHow are ducts professionally cleaned?
Done properly, commercial duct cleaning is a controlled engineering process with measurement at both ends of it. Here is what actually happens on site.
Deduct Ltd technical team · Published · Last updated
BuyingQuestions to ask before appointing a duct cleaning contractor
Quotations for ductwork cleaning vary enormously, and the cheapest is frequently the one that cleans least and evidences nothing. These questions expose the difference.
Deduct Ltd technical team · Published · Last updated
FundamentalsCommon contaminants found inside commercial ductwork
Every ventilation system collects material. What it collects depends on the building, and it tells you a great deal about how the system is performing.
Deduct Ltd technical team · Published · Last updated
Guidance for your environment
Standards and constraints differ by sector. These pages cover what applies where you operate.
Healthcare & NHS
HTM-aware delivery around live clinical activity.
Care Homes
Kitchen, laundry and ventilation risk in residential care.
Commercial & FM
Portfolio scheduling and service charge evidence.
Industrial
Process extraction, shutdown planning and COSHH support.
Marine & Offshore
Drydock programmes and onboard HVAC systems.
Leisure & Public Sector
Pool halls, schools and closure-window delivery.
Have a question the guides do not answer?
Our technical team will give you a straight answer on standards, frequency and evidence — no obligation.