Features and Benefits:
- Home
- 150mm (220mm x 90mm) RytDuct Flat Channel Duct
- Rigid Ducting and Components 220mm x 90mm – 150mm Dia.
- Rytons A1® Fire-rated Retrofit Round Ducting Kits
Rytons A1® Fire-rated Retrofit Round Ducting Kits
- General Details
- Pressure Loss Data
- Golden Thread
- Related Products
- Custom-made metal refurbishment ducting kits compatible with HVAC supply and extract ducting in 100mm, 125mm, and 150mm diameters.
- Installed externally with no access to apartments needed.
- Oversized metal ducting encases in-situ plastic ductwork and terminates with a 50mm wide flange, ensuring secure fixing to the cavity board.
- Made from A1 classified galvanised steel for fire safety, strength and durability.
- Non-combustible, suitable for multi-storey and higher-risk buildings.
- Choice of grille styles to suit different airflow and design requirements.
- Grilles offer low resistance and high airflow, many exceeding 90% of the duct free area.
- Grilles supplied custom powder coated to Class A2-s1, d0, with options from the RAL Classic colour chart in matt, semi-gloss or gloss finishes. Signature architectural finishes available on request.
- Integrated weather protection includes discreet drainage holes and angled louvres to promote water runoff and reduce the risk of transfer into the duct.
- Suitable for:
- The external walls of relevant buildings 11m+ in height or more than 5 storeys, undergoing unsafe cladding remediation work (Building Safety Act 2022).
- The external walls of high-rise relevant buildings over 18m high (11m high in Scotland).
- The external walls of higher-risk buildings at least 18m high or with at least 7 storeys (Building Safety Act 2022).
- The external surfaces of residential purpose group buildings more than 11m high.
- The external surfaces of residential purpose group buildings 11m high or less where an external wall is within 1m of the relevant boundary.
- Bespoke design service available. For further information contact our Technical Sales Office on 01536 511874 or email admin@rytons.com.
- Telescopic fitting grille allows the overall length of the kit to be extended during installation giving the flexibility to handle minor variations in the external façade.
- Image illustrates telescopic feature only.
- Supplied ready to install with no on-site assembly required.
- No screw fixing or sealing needed, saving time and labour and ensuring correct alignment and airtight joints.

A1 Fire Classification Explained:
- Rytons A1® Fire-rated Retrofit Round Ducting Kits are made from galvanised steel. Galvanised steel is considered fire class A1 without testing, as per European Commission paper 96/603/EC referred to in BS EN 13501-1:2018.
- Classification: A1. Definition: Non-combustible. Description: No contribution to fire.
Reference Material:
- England & Wales: view extracts >>
- Approved Document B: Fire safety (Volume 1) (2019 edition incorporating 2020 and 2022 amendments) for England.
- Approved Document B: Fire safety (Volume 2) (2006 edition incorporating 2010, 2013, 2016, 2017 and 2020 amendments) for Wales.
- The Building Safety Act.
- Scotland: view extracts >>
- Building Standards Scotland Domestic Technical Handbook.
- Northern Ireland: view extracts >>
- Technical Booklet B (Materials and workmanship) July 2013.
- Technical Booklet E (Fire safety) 2012.
- Amendments Booklet – 2022 (AMD 7).
Rytons A1® Fire-rated Retrofit Round Ducting Kits:
Rytons A1® Fire-rated Retrofit Ducting Kit 100mm Dia. with Round FlowRyt® Grille
Round FlowRyt® Grille (150mm dia. overall inc. flange with screw holes): 4,990mm² free area.
Custom RAL colour grille in matt, semi-gloss or gloss finish achieving Class A2-s1, d0.
108mm dia. sheet rolled tube to encase in situ ducting 100mm dia.
50mm flange (with eight screw holes) at the end of the tube for fixing.
Custom overall length (refer to drawing).
Properties: Class A1 fire-rated 0.9mm galvanised steel. Class A2-s1, d0 fire-rated RAL colour powder coating. Spot welded. Everbuild Fire Mate intumescent and acoustic sealant used on all gaps.
Registered Design 6235652.
Patent Approved.
Product Code: A1RFDK100.
Download Drawing. | Download Golden Thread.
Rytons A1® Fire-rated Retrofit Ducting Kit 125mm Dia. with Round FlowRyt® Grille
Round FlowRyt® Grille (175mm dia. overall inc. flange with screw holes): 6,912mm² free area.
Custom RAL colour grille in matt, semi-gloss or gloss finish achieving Class A2-s1, d0.
133mm dia. sheet rolled tube to encase in situ ducting 125mm dia.
50mm flange (with eight screw holes) at the end of the tube for fixing.
Custom overall length (refer to drawing).
Properties: Class A1 fire-rated 0.9mm galvanised steel. Class A2-s1, d0 fire-rated RAL colour powder coating. Spot welded. Everbuild Fire Mate intumescent and acoustic sealant used on all gaps.
Registered Design 6235653.
Patent Approved.
Product Code: A1RFDK125.
Download Drawing. | Download Golden Thread.
Rytons A1® Fire-rated Retrofit Ducting Kit 150mm Dia. with Round FlowRyt® Grille
Round FlowRyt® Grille (200mm dia. overall inc. flange with screw holes): 10,680mm² free area.
Custom RAL colour grille in matt, semi-gloss or gloss finish achieving Class A2-s1, d0.
159mm dia. sheet rolled tube to encase in situ ducting 150mm dia.
50mm flange (with eight screw holes) at the end of the tube for fixing.
Custom overall length (refer to drawing).
Properties: Class A1 fire-rated 0.9mm galvanised steel. Class A2-s1, d0 fire-rated RAL colour powder coating. Spot welded. Everbuild Fire Mate intumescent and acoustic sealant used on all gaps.
Registered Design 6235654.
Patent Approved.
Product Code: A1RFDK150.
Download Drawing. | Download Golden Thread.
NBS Source Specifications:
