NAADUK


VENTILATION SYSTEMS INSIDE NAAD-21: AIR & GREASE - 2nd


EDITION The National Association for Air


Duct Specialists (NAADUK) will release an updated edition of its widely used guidance document, NAAD-21: Air & Grease — Version 2 (2025) in late September. The revision brings practical, evidence- based improvements to maintenance,


ventilation grease control and


duct hygiene designed for facilities managers, contractors, fire safety professionals and building owners working across commercial kitchens and other grease-bearing systems.


Why this update matters


Ventilation systems — especially those serving kitchens,


catering


facilities and food production — are complex, safety-critical assets. Poorly maintained systems create hygiene risks, reduce energy efficiency and significantly increase the risk of grease fires. NAAD-21 (2025) consolidates contemporary best practice into a concise technical guide, reflecting recent industry experience and the drive for clearer maintenance regimes and demonstrable compliance. Key updates at a glance


Clearer inspection and cleaning intervals


Offers more prescriptive guidance on inspection frequency and cleaning triggers, moving beyond one-size-fits- all schedules. It recommends risk-


A key addition to NAAD-21 (2025) is a dedicated section on phenolic ductwork,


which is increasingly


common in modern HVAC installations. Enhanced duct hygiene and access guidanceThis new section brings much-needed clarity to an area where inconsistent cleaning practices have historically led to damaged ductwork and costly remedial works.


By


setting out best practice on cleaning and access the systems can be safely maintained to the same high hygiene and fire-safety standards as traditional ductwork.


Enhanced duct hygiene and access guidance


Recognising that access is a major barrier to effective cleaning, NAAD-21 (2025) provides guidance on designing and retrofitting safe access points and inspection ports. The document also recommends hygiene-focused cleaning methods that balance effectiveness with preservation of duct integrity and coatings.


Digital record keeping and verification


based intervals tailored to cooking intensity, fuel type and system design, and includes checklists to help duty holders justify decisions and evidence due diligence.


Phenolic Ductwork


To support auditability, Version 2 encourages standardised digital records for inspections,


cleaning


activities and photographic evidence. The guide proposes a model log format for contractors and owners to demonstrate ongoing compliance and to speed up risk assessments.


Training, competency and contractor management


New guidance clarifies minimum competency expectations for persons carrying out inspection and cleaning work, and sets out practical approaches for client organisations to verify contractor qualifications, insurance and method statements.


NAAD-21: Air & Grease (Version 2 — 2025) is positioned as a pragmatic tool: it helps organisations move from ad-hoc cleaning to a documented, risk-based maintenance programme that improves safety,


downtime and supports regulatory compliance.


For contractors,


reduces it


provides standardized expectations that simplify tendering and quality assurance.


As awareness of duct hygiene and grease management grows, NAADUK’s refreshed guidance arrives at a timely moment for the sector and completely free to the industry from www.naaduk.co.uk.


www.aeme.co.uk | 01404 890 088 | info@aeme.co.uk


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