Specifications Guide

Kitchen Extraction Ductwork

 


For Kitchen Extraction ductwork, the suggested specification can be written as follows.

All Thor Duct® Kitchen Extract will be to the standard prEN15871 and tested to EN1366-1. Insulated to the same period of time as the compartment through which it passes as required in DW172:2018 2nd Edition. Insulation to be used must be as tested in the manufacturers test. Alternatives are not acceptable. The performance of the kitchen extract rating, is taken from thermocouples inside the ductwork inside the furnace, declared in a classification report EN13501-3.

All kitchen extract ducting must be accessible for cleaning and inspection purpose and have a Thor Duct® cleaning door (to the same fire rating, and tested in the proposed system) installed every 2 linear meters as stated in DW172:2018 2nd Edition. The cleaning doors must be as tested in the system.

All ductwork must have classification for testing outside (A) and inside (B) in both a horizontal and vertical position. All ductwork rated “S” for low leakage. A Classification report to EN13501-3 must be provided. Insulation ratings must be both type B and Type A. All kitchen extract ductwork will be tested in a flexible wall and be suitable for installation in stud partition, block wall and concrete floor.

All Kitchen Extract is to be installed under a third-party certifier such as Firas as identified in ASFP TGD 18.

Smoke Extraction Ductwork

 


For Smoke Extraction ductwork, the suggested specification can be written as follows.

All Thor Duct® Smoke Extract ductwork will be to standard EN12101-7 and tested to EN1366-8 for multi compartment or EN1366-9 for single compartment.

Where multi compartment ductwork is required it must be insulated to the same period of time as the compartment through which it passes as required in DW172. Insulation to be used must be included in the manufacturers EN1366-8 test. Alternatives are not acceptable, combinations not accepted.

Evidence of a Factory Production Control (FPC) being in place must be provided.

All Smoke Extract will carry CE Marking or UKCA as appropriate, complying with EU regulation 305. All ductwork must have classification for testing outside (A), inside (B) and smoke extract (C) in both a horizontal and vertical position.

All ductwork rated “S” for smoke leakage and have been tested to high pressure 1500 PA. All smoke extract will be tested in a flexible wall and be suitable for installation in stud partition, block wall and concrete floor.

All Smoke Extract is to be installed under a third-party certifier such as Firas as identified in ASFP TGD 18.

Fire Rated Ductwork 

 


For Fire Rated ductwork, the suggested specification can be written as follows.

All fire rated and pressurisation ductwork will be to standard prEN15871 and tested to EN1366‑1 vertically and horizontally for type A (fire outside) and type B (fire inside).

All ductwork rated “S” for low leakage. All fire rated ductwork will be tested in a flexible wall and be suitable for installation in stud partition, block wall and concrete floor. The performance of the ductwork, Integrity (E) and or Insulation (I) must be determined based on the compartment requirements, giving consideration to the performance required of the wall being crossed.

A Classification report to EN13501-3 must be provided.

All Fire Rated Ductwork is to be installed under a third-party certifier such as Firas as identified in the ASFP TGD 18.

How To Write A Perfect Spec

✓ Written with clarity, and includes all relevant details.

✓ Identification of the correct standards for the project

 Guide the user as to how to identify product suitability

 Incorporate product quality controls

 Validation of installation

✓ Sign off on completion

To this end, we have a suggested wording for specifiers to use for fire ductwork applications, that allow you reflect all the above elements.

For smoke extraction ductwork

 


the suggested specification can be written as follows:

All Thor Duct® Smoke Extract ductwork will be to standard EN12101-7 and tested to EN1366-8 for multi compartment or EN1366-9 for single compartment.

Where multi compartment ductwork is required it must be insulated to the same period of time as the compartment through which it passes as required in DW172. Insulation to be used must be included in the manufacturers EN 1366-8 test. Alternatives are not acceptable, combinations not accepted.

Evidence of a Factory Production Control (FPC) being in place must be provided.

All Smoke Extract will carry CE Marking or UKCA as appropriate, complying with EU regulation 305. All ductwork must have classification for testing outside (A), inside (B) and smoke extract (C) in both a horizontal and vertical position.

All ductwork rated “S” for smoke leakage and have been tested to high pressure 1500 PA. All smoke extract will be tested in a flexible wall and be suitable for installation in stud partition, block wall and concrete floor.

All Smoke Extract is to be installed under a third-party certifier such as Firas as identified in ASFP TGD 18.

For Kitchen Extract

 


the suggested specification can be written as follows:

All Thor Duct® Kitchen Extract will be to the standard prEN15871 and tested to EN1366-1. Insulated to the same period of time as the compartment through which it passes as required in DW172:2018 2nd Edition. Insulation to be used must be as tested in the manufacturers test. Alternatives are not acceptable. The performance of the kitchen extract rating, is taken from thermocouples inside the ductwork inside the furnace, declared in a classification report EN13501-3.

All kitchen extract ducting must be accessible for cleaning and inspection purpose and have a Thor Duct® cleaning door (to the same fire rating, and tested in the proposed system) installed every 2 linear meters as stated in DW172:2018 2nd Edition. The cleaning doors must be as tested in the system.

All ductwork must have classification for testing outside (A) and inside (B) in both a horizontal and vertical position. All ductwork rated “S” for low leakage. A Classification report to EN13501-3 must be provided. Insulation ratings must be both type B and Type A. All kitchen extract ductwork will be tested in a flexible wall and be suitable for installation in stud partition, block wall and concrete floor.

All Kitchen Extract is to be installed under a third-party certifier such as Firas as identified in ASFP TGD 18.

For Fire Rated Duct 

 


for applications other than kitchen and smoke, the suggested specification can be written as follows:

All fire rated and pressurisation ductwork will be to standard prEN15871 and tested to EN1366‑1 vertically and horizontally for type A (fire outside) and type B (fire inside).

All ductwork rated “S” for low leakage. All fire rated ductwork will be tested in a flexible wall and be suitable for installation in stud partition, block wall and concrete floor. The performance of the ductwork, Integrity (E) and or Insulation (I) must be determined based on the compartment requirements, giving consideration to the performance required of the wall being crossed.

A Classification report to EN13501-3 must be provided.

All Fire Rated Ductwork is to be installed under a third-party certifier such as Firas as identified in the ASFP TGD 18.

Understanding EN Regulations

European Standards automatically become national standards in each of the 34 CEN-CENELEC member countries. What this means is when an EN standard is approved (harmonised) the local standard must be withdrawn.

Ductwork is split between smoke control ducts and fire resisting ducts.

Smoke Control Ducts are subject to an EN standard. Since July 2013 all smoke extract systems must comply with the standard EN12101-7, and be classified to EN standard 13501-4. The test standards are, multi-compartment EN1366-8 and single-compartment EN1366-9. In keeping with the requirements of the Construction Products Directive, Regulation 305, all smoke extract ducts must carry the CE symbol, or in the UK, the UKCA symbol. Factory production control must be in place with the manufacturer, and a manufacturer must demonstrate this.

Smoke Control Ducts are ventilation ducts used to exhaust smoke or heat during a fire. Make up air systems are also considered part of the smoke control system. Smoke Control Ducts in multi-compartment applications must prevent flashover from occurring.

The test standard EN1366-8 states


Top 5 Questions About Smoke Extract

Part of the Thor Duct® service for licensed manufacturers, is that we will engage with consultant engineers on any technical issues relating to the fire and smoke ductwork. Here are some of the most frequently asked questions that we get asked by M&E Contractors, installers and fire authorities about smoke extract, flashover, thermal insulation, and fire dampers. 


Is smoke extract in multi-compartments always insulated?

 
 
  • Can I use any thermal or fire insulation I choose on a smoke duct?
 
  • Does smoke extract ductwork need to be insulated on the roof?
 
  • What is the difference between EN1366-8 and EN1366-9?
 
  • Are EN1366-2 Fire Dampers suitable for EN1366-8 smoke ducts?
 

Here are some of the most frequently asked questions asked by HVAC fire duct workers about commercial kitchen smoke and fire ducting.


  • How is a commercial kitchen fire duct rating measured?
 
  • Do I need to insulate inside the kitchen?
 
  • Can I put a fire damper in a kitchen extract?
 
  • What is the standard for commercial kitchen extract ductwork?
 
  • Do cleaning doors need to be fire tested?
 

Thor Duct® is one of the world’s leaders in design and manufacture of fire duct and compliance with EN safety standards. Our Chief Technical Officer, Michael Renaghan, is a thought leader in the industry and regularly advises Consultants, Specifiers, and M&E Contractors on general and specific issues in relation to fire ducting.

Here are the top questions on fire duct and issues relating to insulation, large duct, BS and EN. 


  • Why can’t I just use insulation?
 
  • What should I do with duct that is bigger than 1250mm?
 
  • I’m OK to use BS. Can I still specify BS476 fire ducts?
 
  • Can I hang other services from my fire ductwork?
 
  • Why is my ductwork only E60?
 
  • What must we consider for fire rating of protected stairways, lobbies and corridors?

Who benefits?

 


✓ Specifiers

✓ Fire engineers and mechanical engineers

 Local authorities, building control officers

✓ Fire departments

 Ductwork installers

You will learn

 


✓ Testing methods

✓ Understanding of EN standards for fire ducts

✓ CE marking and quality standards

✓ Risk assessment for smoke and kitchen ducts

✓ Understanding a classification report

The course is delivered in person with certified CPD units. Participants will have access to our online video tutorials.

 

Find Out About Our CPD’s