Fire Rated Duct Systems

Fenland Fire Rated Duct System

Approximately 85% of deaths in fire situations are caused by smoke inhalation. Non-fire-resistant ductwork systems can be responsible for allowing the initial spread of fire between compartments, and the rapid spread of smoke and decomposition products. The correct use of fire-resistant ductwork will ensure fire compartmentation and assist in the safe dispersal of smoke and hazardous fumes.
The Fenland Fire Duct System is an augmented ductwork construction utilizing the latest manufacturing techniques to which an intumescent coating is factory applied. As the coating is spray applied, this allows the ductwork system to be manufactured in any cross-sectional shape to suit the application. Thus, producing a flanged single skin Fire Rated Ductwork system that ensures stability and integrity of up to 4 hours.

Leminar Air Conditioning Industries, a fire rated duct manufacturer in India is the sole manufacturing licensee for Fenland Fire Duct System-UK for the geographical market covering UAE, Oman, Bahrain, and Kuwait. All Leminar personnel are trained by Fenland Fire Contracts Ltd. UK (FFC-UK) for its applications and constructional requirements.

The Fenland Fire Duct System complies with the requirements of Method 3 of BS 5588 Part 9: 1989 & Method 3 (clause: of BS 9999:2008; has been fully tested in accordance with BS 476 Part 24: 1987 (ISO 6944: 1985) up to 4 hours stability and integrity for Type A ducts (Fire outside) and up to 3 hours stability, integrity and 2 hours insulation for Type B ducts (fire inside).

The Fenland Fire Duct System has been tested and assessed by the BRE Centre for Fire Resistance (formerly the Loss Prevention Council Board - LPCB) to be suitable for use as, "a Fire Rated Ventilation Duct, a Smoke Extract/Outlet Duct or a Kitchen Extract Duct. The same is assessed by LPCB (UK), Warringtonfire Exova (UK) and listed in their Mideast scheme.

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Type A Duct (Fire Outside)

- Up to 4 hours- stability, integrity and insulation.
- Typical for escape lobby ventilation and staircase pressurization systems.

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Type B Duct (Fire Inside)

- Up to 3 hours- stability, integrity and 2 hours insulation.
- Typical for kitchen extract, smoke extract, and other re-rated systems.

in accordance with bs 476 part 24:

1987 for the fire resistance of ventilation ductwork which is expressed as the duration of heating in accordance with the ISO 834: 1985 (Cellulosic - Standard Time/Temperature Curve) until failure occurs due to one or more criteria :



Stability failure shall be deemed to have occurred in duct ’A’ within the furnace and in ducts ‘A’ and ‘B’ outside the furnace when the duct no longer fulfills its intended function. (For smoke outlet duct stability failure will also be deemed to have occurred when there is any restriction of the cross-sectional area of the duct to 75% or less of its original area).


The presence and formation of any cracks, holes, or other openings outside the furnace through which flames or hot gases can pass


Insulation failure shall be deemed to have occurred when the initial ambient temperature on the unexposed surface of the duct outside the furnace exceeds either:

  • 140°C as an average value above ambient
  • 180°C as a maximum value above ambient. For a Kitchen extract duct (Type A), these temperature limits also apply to the inside surface of the duct within the furnace.

Reasons to choose Leminar

  • The FFC-UK fire rated duct system is tested to the most stringent international standards and certified by independent laboratories.
  • FFC-UK Duct System has been approved by the local Fire and Safety authorities such as Dubai Civil Defence, Abu Dhabi Civil Defence, Royal Oman Police, EHS Dept. of JAFZA, ADNOC, MOPW, Royal Court of Affairs-Muscat-Oman on their various projects.
  • All raw materials like the FFC 250 coating, FFC Intumescent gaskets and FFC Intumescent Acrylic sealant are manufactured and imported from the UK.
  • Leminar shall assist with any technical issues or concerns that may arise during Installation at the site.
  • FFC-UK Duct System has been approved by all the major MEP consultants / clients and used for various prestigious projects.
  • Leminar is the only company in the region, with facilities like duct fabrication and fire rated coating application, all under one roof. This ensures stringent quality control, easy coordination due to single point responsibility and faster deliveries.
  • Leminar strictly follows the method statement for fabrication of the ducts as defined by FFC-UK for duct fabrication to ensure compliance with test standards.
  • FFC fire rated duct system will be provided with 2 hours and 4 hours fire rating for insulation criteria for smoke extract ducts experiencing rise in temperatures of up to 600°C. FFC 250 fire rating itself will provide 2 hours and 4 hours insulation resistance and hence no external insulation is required in such cases. This will assist in keeping the expensive insulation cost to a minimum and this works very well for places with acute space constraint

Example Specification

The Smoke Extract ductwork should be constructed in accordance with the Fenland Fire Duct specification for Fire Resistant ductwork, to provide 120 Minutes Stability, 120 Minutes Integrity and 120 Minutes Insulation (or 120 Minutes fire Insulation to suit a smoke temperature of 300 °C) when tested to the requirements of BS476 part 24: 1987 by a recognised NAMAS/UKAS Accredited laboratory.
The ductwork systems should be manufactured and installed in accordance with BS5588 part 9 : 1999, and be capable of providing type ‘B’ fire containment. Under normal non-fire operating conditions the ductwork should conform to the class C pressure/leakage classification of the current HVCA DW/144 specification for sheet.

Major Projects

  • Deloitte Ecoworld Bangalore, India
  • Chirst University Bangalore, India
  • MMTH Bangalore International Airport Limited (BIAL), India
  • Micron Aquila Hyderabad, India
  • ZF India Technology Center Hyderabad, India
  • Rajapushpa Paradigm Hyderabad, India
  • Arete Hospital Hyderabad, India
  • Goldman Sachs, Salapuria Sattva Knowledge City, Hyderabad, India
  • My Home Mangala Hyderabad, India
  • KRC Hetero B2 Hyderabad, India
  • Anjani Cement Factory, Hyderabad, India
  • AI Sufoh Transit System – Dubai Tram
  • Bright Star Beach Resort
  • Fairmont Residence, Palm Jumeirah, Dubai
  • Royal Opera House – Cultural Souk & Park, Muscat, Oman
  • Finance House Headquarters, Abu Dhabi
  • H.H. The Rulers Court Office Building, Dubai
  • National Reference Laboratory, Abu Dhabi
  • Al Fatan Hotel & Residences, Palm Jumeirah, Dubai
  • Emirates Flight Catering Expansion, Dubai
  • Petroleum Institute Staff Accommodation, Abu Dhabi
  • Male and Female Health Clubs, Ruwais, Abu Dhabi
  • Habib Bank Zurich Headquarters, Dubai
  • Abu Dhabi Shooting Club
  • Fujairah City Center
  • Zabeel Ladies Club, Dubai
  • Holiday Inn Hotel, Muscat
  • Zuleka Hospital, Sharjah
  • Petrofac Office Tower II, Sharjah
  • Dream Tower, Dubai Marina
  • Bawadi Mall, Al Ain
  • Al Ain Mall & Resort, Al Ain
  • Abu Dhabi Future Schools, Abu Dhabi
  • Al Nasser Headquarters Building, Abu Dhabi
  • Meydan Hotel & Granstand, Dubai, UAE
  • Al Ghandi Auto New Car Showroom, Dubai
  • Al·Reef Down Town, Abu Dhabi
  • SCA Building 4B+G+10+HC On Plot no. 214·741, AI Garhoud, Dubai
  • Home Center Store at Mirdif City Center, Dubai
  • PPM Conrad Hotel, Dubai
  • Central Park At DIFC, Dubai
  • Palazo Hotel, Dubai
  • Mercury Grand Hotel/Pullman Hotel, Dubai
  • Home Decor at Mirdif City Center, Dubai
  • Center Point & E·Max at Mirdif City Centre, Dubai
  • Ministry of Defence, Seeb, Oman
  • City of Lights, Al Rheem Island, Abu Dhabi
  • RTA Bus Depot, Al Khawneej, Dubai
  • East Hotel, Mall of Emirates, Dubai
  • Kidzania, Cinemas, Entertainment Centre, Dubai Mall, Dubai
  • Jimmi Mall, AI Ain
  • Medical Center, Dubai Mall, Dubai
  • Marina Hotel, Yas Island, Abu Dhabi
  • M1 Tower, Jumeirah lake Towers, Dubai
  • G+4,(Bldgs)+G+15(1 Bldg) Offices, Dubai Studio City, Dubai
  • Laguna Hotel Jumeirah Lake Tower, Dubai
  • Concord Tower Jumeirah Lake Tower, Dubai
  • Bonnington Tower, Jumeirah Lake Tower, Dubai
  • Hotel H-01 Jumeirah Beach Residences, Dubai
  • Raffles Hotel Wafi Mall, Dubai, UAE