BS EN 1716 Calorific Value Test - Article Example

Note: THIS IS WHAT YOU ARE GOING TO SAY DURING THE PRESENTATION. The questions requested are in page 8. The references include links of the books. The presentation file is ISO1716.ppt (Check your email for the link) BS EN (ISO) 1716 Calorific Value Test and how it compares with the Cone Calorimeter Test; and how could the 1716 test assist in classifying hazard and/or risk of fire in a typical university lecture room, such as Mb41? Also, trace the history of the test and express a logically derived opinion of its usefulness and its limitations for fire safety conscious building designers. 1. Introduction Fire presents hazards to life and property because of toxic gases, suffocating smoke, and too much heat. These hazards are primarily generated by products made of combustible materials which unfortunately are being used in residential, private, government, industrial, and transportation. For this reason, a number of fire scenarios need to be considered for testing of products and there are methods required to comply with specific regulations or legislations. The following section discusses two known test method, the BS EN ISO 1716 Calorific Value Test and the Cone Calorimeter Test. 2. BS EN(ISO) 1716 Calorific Value Test The ISO 1716 for calorific value of materials is types of test widely used in relation with flammability test methods in order to know and classify materials for building regulations. For instance, materials with a calorific value of less than 2500 kJ/kg in France are considered for M0 or given the highest classification. Moreover, to measure the calorific potential of materials, a bomb calorimetric method is used (Murphy 1998, p.429). This method determines the calorific value of non-metal containing building material by using a high-pressure bomb in a water jacket immersed in a calorimeter vessel containing water. The selected sample is contained in a crucible in the bomb, which pressurized with oxygen then ignited electrically to determine the peak temperature of the water jacket. Using particular formulae, the net calorific potential is calculated. This method determines the heat of total combustion rather than the heat release rate which were common in previous methods (Brown 1999, p.682). The BS EN ISO 1716 can be applied mainly along with other test methods such EN 13823 or the Single Burning Item test, EN ISO 9239-1 or the Radiant Panel test, EN ISO 1182 or the Non-Combustibility test, etc, for classification required by Euroclass for non-combustible building products. Some of the materials that can be tested with BS EN ISO 1716 are insulation products of mineral wool, fibre reinforced cement, silicate boards, sealing compound, and others. The specimen used in this type of test measures at 250 mm x 250 mm and weighing 50 grams (SP Technical Research Institute of Sweden 2009, p.1). Some examples of calorific values determined by this method are below: Material Calorific Value (MJ/kg) Stone wool 0.8-1.8 Wood 19 Rubber 32 Phenolformaldehyde 29 Polyester 31 Polystyrene 40 Polyurethane foam 26 Polyisocyanurate foam 24 Ureaformaldehyde foam 14 3. Cone Calorimeter Test The Cone Calorimeter test is known as ISO 5660 and its bench-scale test to determine the reaction to fire for surface lining materials that is being use in building construction. A typical set up of apparatus for this test is below: In this test, specimen usually measures 100mm x 100mm with a thickness of about 6mm to 50 mm (Hume 1992, p.4). The specimen is mounted in low heat loss insulating ceramic material horizontally and being exposed to a heat flux from an electric heater ranging from 25 to 75 kW/m2. The mixture of gases above the specimen is then ignited by an electric spark source when it reaches a level above the lower flammability limit. The test usually ends after 10 minutes but may be longer in some cases depending on the material being tested. The main results of this test are time to ignition or TTI, Mass loss rate or MLR, and Heat Release rate or HRR (Horrocks & Price 2001, p.360). 4. Comparison Between BS EN (ISO) 1716 Calorific Value Test and Cone Calorimeter Test As mentioned earlier with BS EN (ISO) 1716 Calorific Value Test, the method measures the heat of total combustion rather than the heat release rate. In the Cone Calorimeter test, the time to ignition, mass loss rate, and heat release are generally included in the recording of data and presentation of results. In other words, in ISO 1716 the complete heat of combustion of building materials is assessed with a bomb calorimetric method as opposed to the effective heat of combustion in a particular fire scenario measured by the cone calorimeter. In determining the calorific value of non-metal containing material used in building construction, the BS EN (ISO) 1716 employs a high-pressure bomb in a water jacket inside a calorimeter vessel with water. The sample is then placed in a crucible in the bomb where it is ignited electrically. In contrast, the cone calorimeter test is mounting the specimen in a low heat loss ceramic material insulation which will then be subject to heat flux exposure generated by an electric heater. In BS EN (ISO) 1716, the peak temperature of the water jacket is measured and calculated to determine the net calorific potential. In Cone Calorimeter test on the other hand, ignite and burn the mixture of gases under a collecting hood where they can be measured continuously until the fire die out. 5. Classifying hazard or risk in typical university lecture room with BS EN (ISO) 1716 Classifying hazard or risk in a typical university lecture room with BS EN (ISO) 1716 is possible since the level of risk of a room depends on the construction products used in construction. For instance, with the exception of flooring, performance of building materials in terms of reaction to fire is being classified through BS EN 13501-1:2002 for Fire Classification of Construction Products and Building Elements. They are classified as A1, A2, B, C, D, E or F with A1 as the highest in terms of performance. However, these classifications depends on the data from reaction to fire tests which BS EN ISO 1716:2002 or Reaction to Fire Test for Building Products for determination of the gross calorific value is being recognised. Another is the recognition that test results from BS EN ISO 1716 can be use to determine materials with limited combustibility (Communities and Local Government 2007, p.121). 6. History, Usefulness, and Limitations of BS EN (ISO) 1716 in building’s fire safety designs. Before, the Euroclass system is adopted by the EU Members, a building product is required to pass the test and classification of the country in which they are being sold. In recent years, the member of the European Union started to adopt a harmonized Euroclass system of reaction to fire performance of materials used in building construction. The move was inspired by the Commission Decision 94/611/EC that had implemented Article 20 of Directive 89/106/EEC that requires construction products to satisfy one common requirement for fire safety. The purpose of the Euroclass system is to enable trade of building of materials between European Members without the difficulty of having to pass different test methods and classification system of each country. Consequently, national standards of each country regarding building products reaction to fire is gradually changing and being replaced by new common European standards. The new system now includes a classification system that would enable identification of products based on the reaction to fire and test methods that will be use to categorise them. However, testing and classification of building products does not include those that are use for floor finishing or surface linings. All construction products or building materials are being classified into one of six Euroclasses from A to F which are arranged according to their reaction to fire in a fire test. One of these tests is a furnace test for non-combustibility based on ISO 1182 and the other is oxygen bomb calorimeter test based on the ISO 1716 with few modifications in order to further enhance consistency of operation (Dinwoodie 2000, p.218). The BS EN ISO 1716 is the UK version of the ISO 1716 and it is exclusively for measuring the gross calorific potential of a building product or the potential maximum total heat release when a product is completely burned. This test method is not intended for measuring or identifying products that are not likely to contribute to fire which EN ISO 1182 is intended for. It is also not for testing the ignitability of building products since EN ISO 11925-2 is the test method more suitable for this purpose. Similarly, it cannot be use to test floor coverings because along with Radian Panel test, EN ISO 9239-2 is more likely to produce credible results (VTT 2009, p.1). However, BS EN ISO 1716 is very useful in building’s fire safety design when it is use to test the gross calorific potential (PCS) of homogenous products and substantial components of non-homogenous products. It is also useful in determining the PCS of any external non-substantial component of non-homogenous products and the product as a whole. According to Davies (2001, p.100), other products that is not included in the commission’s list of products that may be given the highest performance in reaction to fire without testing, may be granted class A1 or A2 on the basis of test done using ISO 1182 and ISO 1716 (VTT 2009, p.1). 7. Possible Questions from Audience 1. What is the main difference between BS EN ISO 1716 and Cone Calorimeter Test? 2. What is the difference in the size of specimen? Why? 3. What are the building products that can be tested with ISO 1716? 4. What are other test methods that can help in ensuring fire safety in building? 5. Why BS EN ISO 1716 is not being test floor coverings? 6. What is Euroclass System? Why it is being adopted? 8. Reference List Communities and Local Government, 2007, The Building Regulations 2000: Fire Safety- Approved Document B, Volume 2 – Building other than DwellingHouses, Office of Public Section Information, UK Brown R. 1999. Handbook of polymer testing: physical methods. CRC Press, US Link for this book: http://books.google.com/books?id=44ilOV1F3HwC&pg=PA682&dq=heat+of+total+combustion++brown&lr=&as_brr=3&cd=1#v=onepage&q=&f=false Davies J. 2001. Lightweight sandwich construction, Wiley-Blackwell, UK Link for this book: http://books.google.com/books?id=WExD7PEvJ4QC&pg=PA100&dq=EUROCLASS+System+1716&lr=&as_brr=3&cd=1#v=onepage&q=EUROCLASS%20System%201716&f=false Dimwoodie J. 2000. Timber, its Nature and Behaviour, Taylor & Francis, UK Link for this book: http://books.google.com/books?id=gpxVSGWWfL4C&pg=PA218&dq=BS+EN+ISO+1716&lr=&as_brr=3&cd=8#v=onepage&q=BS%20EN%20ISO%201716&f=false Horrocks A. & Price D. 2001, Fire retardant materials. Woodhead Publishing, UK Link for this book: http://books.google.com/books?id=bUqpYyg4__kC&pg=PA357&dq=EUROCLASS+System+1716&lr=&as_brr=3&cd=3#v=onepage&q=&f=false Hume B, 1992, The Cone Calorimeter: A Small Scale Test Method for Fire Growth, Home Office Fire Research and Development Group, London, UK Murphy J. 2001, Additives for Plastics Handbook, Elsevier, UK Link for this book: http://books.google.com/books?id=D0mWq591WnwC&pg=PA286&dq=bomb+calorimetric+method++murphy&lr=&as_brr=3&cd=1#v=onepage&q=&f=false SP Technical Research Institute of Sweden, 2009, Information Sheet EN ISO 1716, available online at http://www.sp.se/en/index/services/reaction_to_fire/ENISO1716/Sidor/default.aspx VTT, 2009, Euroclass System, available at http://virtual.vtt.fi/virtual/innofirewood/stateoftheart/database/euroclass/euroclass.html Read More