Engineering Design Practice - Assignment Example

Surname: Presented to Institution Name, Location Date Engineering design practice What is fire resistance testing? There is a clear requirement in many buildings that products such as doors, partitions, ceilings and screens should resist any passage of fire into the building or within the building. These particular products are very important in making sure that they control the growth or spread of fire, they technically protect both the life of individuals and their properties by allowing the occupants of the building to escape and the fire fighters to enter. Resistance is therefore a legal requirement for such products as doors and screens for spread of fire. Both the location and the period of fire resistance is determined by the given relevant legislation, the accepting authority, or the codes of practice. In countries such as England and whales, the legislation with respect to the fire resistance are given in the Approved Document B both in parts 1 and 2(Great Britain. & Great Britain, 2007). Fire resistance can be gauged using the destructive fire testing that is designed to replicate the products that is intended to be used. The specimen that has to be tested is built into a more appropriate supporting construction, then it is built into a more resistant frame and mounted on the front side of the furnace. The temperature given out within the furnace is managed according to an internationally accepted temperature regime and duration of time (Great Britain. & Great Britain, 2007) What is reaction to fire testing? Reaction to fire refers to the measurement of how a material or a particular system will contribute to the development of fire and its distribution. This is done and focused particularly in the initial stages of fire when the need for evacuation is paramount. The terms that are used to describe this process include SBI, SFI, flammability, surface spread of fire, and ignitability. The reaction to fire testing is very important since it determines how easy it will be for the people inside the building to escape depending on the ease for the products to get ignited, produce energy and spread the fire (Great Britain. & Great Britain, 2007). The reaction to fire testing is required in order to comply with construction of building regulations. Within England and whales, these regulations are covered in the Approved Document B. The reaction to fire testing is needed for specific products that are destined for application in a railway and they should be produced in accordance with DD CEN TS 45545 standards (Department of the Environment, 1992). Under the building regulations, even when there is no reaction to fire testing needed, a relevant authority or insurer for that particular building may request for a batter and more enhanced reaction to fire performance which requires testing. Some of the manufacturers have a culture of testing their product to know more, or to show how superior their products are in the market (Great Britain. & Great Britain, 2007). The reaction to fire testing can be done for products with many different performance level. The products that do not easily combust will not give observable results for the test designed to challenge the product that will easily ignite. Hence, due to this reason, a range of the European tests that are used to cover the diverse classifications, since there is a range of tests used within the British standards. The classification of the standard used in the European fire reaction testing are as listed below (Department of the Environment, 1992). Classification Relevant test standard A1 BS EN ISO 1716 BS EN ISO 1182 A2 BS EN ISO 1716 BS EN ISO 1182 BS EN 13823 B, C, D BS EN ISO 11925-2 BS EN 13823 E BS EN ISO 11925-2 Flammability limits This refers to the range of compositions for either fixed pressure or temperature within which a particular explosive reaction is possible when ignition from an external source is availed. This can always take place even when the substance mixture is very cold (Department of the Environment, 1992). The flammability limits are always given in terms of concentration of the fuel mainly by volume at a specific level of either temperature or pressure. A good example is when there is a lean flammability limits for jet A for the aviation kerosene in the air at the sea level refer to its concentration by volume or its partial pressure of about 0.7%. The rich flammability limits is just about 4.8% by either its partial pressure of volume (Department of the Environment, 1992). The limits of flammability are not absolute, they depend mainly on the strength and the type of the material of the ignition source. According to studies done on flammability limits of hydrocarbons, they have shown that the stronger the stimulus of the ignition source, the leaner the mixture that can be ignited. The limits of flammability depend mainly on the type of atmosphere, the temperature and the atmospheric pressure. An example is that the limits are much wider with oxygen as compared with that of air (Great Britain. & Great Britain, 2007). Effects of temperature on flammability limits Temperature is one of the main factors that affect flammability. It has been proven through practices that the range of flammability widens as temperature increases. The equation given bellow which was derived by Zabetakis can be used to provide an estimation how temperature affects the flammability limits (Department of the Environment, 1992). Different elements have varied flammability effects when temperature is elevated. The table given bellow provide the list of the flammability limits of toluene and benzene at the given elevated temperature. For many gases that are flammable, their LFL decreases by about 8% of and their UFL increases at about 8% as the temperature is increased by 100%. The presence of oxygen or any other oxidant that include chlorine, nitric oxide, nitrous oxide and many others have significant effect on the limits of flammability. The UFL increase with increase with the increase in the concentration of oxygen (Great Britain. & Great Britain, 2007). Heat release rate in relation to fire hazards Heat release rate refer to the rates at which fire releases energy. This can also be referred to as power. It is measured in units called watts (W) which is one of the international systems. It is equal to one joule per second (Department of the Environment, 1992). Heat release rate measurements is the most important variable while doing the characterizing process of flammability of the manufactured products and their consequent fire hazards. The rates of heat release of products is the most appropriate predictor of the fire hazards. The reaction to fire test have been used for a long time, it is very important as for every building as it determined the likelihood of development of fire hazards in the rooms (Great Britain, 2006). Most of deaths caused by fire is due to the toxic substances of combustion. The actual fire hazards that happen depend on many factors that include: the toxic patency and rapidity of ignition of the products. The ability to predict fire hazards is very recent, it is only until 1982 that the first standard method of measuring heat release was discovered. At the moment, all the tool that is required for correct quantitative computation of room fire hazards are available (Great Britain. & Great Britain, 2007). To determine the importance of measuring the rate of heat release, we take into consideration the typical fire where the death or the injuries that victim gets is from the source of ignition and not in the immediate contact with the person (Great Britain, 2006). The fire is deemed to spread then causes death or injury of the person. These types of fires can be broken down into their constituent phenomena which include; ignition, spread of flame, rate of heat release, mass lose rate, smoke release rate, and toxic gases(Department of the Environment, 1992). The real scale of fire hazards can be assessed very closely by tracking the incapacitation or the mortality of the building occupants mainly during the cause of fire. An increase hazard is pin pointed by mortality or incapacitation of the victims. From the variable given above, the one which is mostly associated with the increased fire hazards is the heat release rate. This has been reached to through experiments done on various products (Great Britain. & Great Britain, 2007). Factors which will influence the fire development and the rate of fire growth within a compartment Fire development and spread has many factors that contribute to its increase. Some of the most common fire factors include the compartment geometry, fuel properties, ventilation, location of fire, and the ambient conditions such as wind and temperature (Department of the Environment, 1992). When the fire is not confined then much of the heat that is produced will escape through either radiation or convection. Through these heat transmission modes the rate of heat development will be reduced. The materials within the compartment such as walls, and the ceilings will absorb the radiant heat that is generated. This will lead to accumulation of heat within the building and depending on the ignition rates of the materials this can increase the rate of combustion and development of fire (Great Britain. & Great Britain, 2007). The hot smoke and the air that is heated by the fire will become more buoyant and raises, this will warm the cooler parts of the ceilings and the walls of the compartments. This will turn into fuel and accelerate the rate of spread of fire. The ventilation profile is also the most critical factor in the development and spread of fire within the apartment (Department of the Environment, 1992). PART B 1. The five functional requirements of the approved document B include; 1. Means of escape 2. Internal fire spread (linings) 3. Internal fire spread (structure) 4. External fire spread 5. Access and facilities for the fire services 2. The means of escape and warning states that a building should be designed and constructed in a way that there are appropriate and very early warning and escape from fire provisions. The means of escape to a safer place outside the building should be available and be ready to be used at every other given time. Means of escape refers to availability of mean in which an individual can run away of the building when it is on fire. 3. The maximum compartments required for; A) A single storey shop with a sprinkler protection is one B) A single storey industrial unit is two 4. Four meters 5. (A) For an office building with a top occupied floor 250 meters square and located 19 meters above the service vehicle will require a fighting this is due to its height which might be so high for the fighter to efficiently fight the fire. A fighting lift will also be needed due to its (B) For a four story assembly building with a top storey of 1400 meters square located 10 M above the fire service vehicles access level will not require a fighting lift but a fighting shaft has to be there this is due to its height and surface area. 6. A) More than 60 minutes B) Less than 60 minutes 7 a) Guide to fire Precautions in Existing Hotels, Guesthouses and Similar Premises b) Code of Practice for Safety in Indoor Concerts c) Code of Practice for Fire Safety of Furnishings and Fittings in Places of Assembly d) Code of Practice for Fire Safety of Furnishings and Fittings in Places of Assembly 8. According to Table 2 of ADB, what are the recommended travel distance limitations? (a) Single direction 25 and multiple directions 45 (b) Single direction 9 and multiple directions 18 (c) Single direction 9 and multiple directions 35 (d) Single direction 18 and multiple directions 35 (e) Single direction 25 and multiple directions 45 f) Single direction 24 and multiple direction 35 1) 9. According to Table 3 of ADB, what is the recommended minimum number of escape routes from a storey with a) 2 b) 25 c) 36 d) 40 10. According to Table 4 of ADB, what is the minimum exit width required to accommodate: a) 2 b) 2 c) 1 d) 2 11. A building with four above ground floors is served by two escape stairs without lobby protection. Using Table 7 of ADB, what is the minimum width of the escape stairs if each floor accommodates? (a) 6 M (b) 10M 12. A building with five above ground floors is served by three escape stairs with lobby protection. Using Table 7 of ADB, what is the minimum width of the escape stairs if each floor accommodates? (a) 8 M (b) 10M 13. Assuming 100 occupants from the ground floor accommodation also exit through the ground floor of the stair enclosures for Questions 11 and 12, how wide do the final exits need to be? (I.e. a merging flow – diagram 15 and associated equation). 11. (A) 12M (b) 20M 12. (A) 16M (b) 20M 14. According to Table C1, what floor space factors would be appropriate in the following areas? a) Have proper furniture and carpets b) Have low ignition rate c) should be fire resistant 15. For a square room, 40m by 40m, calculate the number of occupants using the floor space factors obtained in Question 14. In each case what is the minimum number of exits required and how wide should each exit be as a minimum: a) 4 b) 6 c) 8 16. What is meant by the following terms? a) Safety: this refers to the condition of being safe from being hurt, injured, or lost through tragic occurrences such as fires b) Property protection: these refers to the measure that are put in place by the owners of these assets to make sure that they prevent any form of damage that can come from such hazards as fire. c) Fire life protection refers to the process of making sure that the life of individuals living in a building are well protected by installing materials that are resistant to catching fires. d) Cavity barrier refers to the position where a barrier that in a concealed space is made to coincide with the compartment floor or wall, this will it will always be required to give the same fire performance as within the wall of the floor. Cavity barrier is the barrier that is located between such floor and walls. 17. Figure 1 and Figure 1a below represents a two storey office building, from the dimensions give an estimate for internal room sizes. With reference to Figures 1 and 1a determine: a) The travel distance from one room to another is approximately 5M while from one floor to another is 7M b) Occupancy load: the surface area of each room is about 25 M^2 this will be less than 50 for each room c) The purpose group of the building could either be office, residential or commercial. d) The exits of the building should be 1.5 meters and the final exits about 2 meters. e) The width of the stairways should be 1.5 meters f) The external and internal walls should be fire resistant, they have to be of low ignition and generate little smoke and fumes. References Great Britain. & Great Britain. (2007). Approved document B: Vol. 1. London: NBS for the Department for Communities and Local Government. Great Britain. (2013). The Building Regulations 2010: Approved document B. Newcastle upon Tyne: NBS. Department of the Environment. (1992). the Building Regulations 1991. Approved document B: Fire safety. London: H.M.S.O. Great Britain. (2006). The Building Regulations 2000: Fire safety: approved document B. London: NBS. Read More

Fire resistance can be gauged using the destructive fire testing that is designed to replicate the products that is intended to be used. The specimen that has to be tested is built into a more appropriate supporting construction, then it is built into a more resistant frame and mounted on the front side of the furnace. The temperature given out within the furnace is managed according to an internationally accepted temperature regime and duration of time (Great Britain. & Great Britain, 2007) What is reaction to fire testing?

Reaction to fire refers to the measurement of how a material or a particular system will contribute to the development of fire and its distribution. This is done and focused particularly in the initial stages of fire when the need for evacuation is paramount. The terms that are used to describe this process include SBI, SFI, flammability, surface spread of fire, and ignitability. The reaction to fire testing is very important since it determines how easy it will be for the people inside the building to escape depending on the ease for the products to get ignited, produce energy and spread the fire (Great Britain.

& Great Britain, 2007). The reaction to fire testing is required in order to comply with construction of building regulations. Within England and whales, these regulations are covered in the Approved Document B. The reaction to fire testing is needed for specific products that are destined for application in a railway and they should be produced in accordance with DD CEN TS 45545 standards (Department of the Environment, 1992). Under the building regulations, even when there is no reaction to fire testing needed, a relevant authority or insurer for that particular building may request for a batter and more enhanced reaction to fire performance which requires testing.

Some of the manufacturers have a culture of testing their product to know more, or to show how superior their products are in the market (Great Britain. & Great Britain, 2007). The reaction to fire testing can be done for products with many different performance level. The products that do not easily combust will not give observable results for the test designed to challenge the product that will easily ignite. Hence, due to this reason, a range of the European tests that are used to cover the diverse classifications, since there is a range of tests used within the British standards.

The classification of the standard used in the European fire reaction testing are as listed below (Department of the Environment, 1992). Classification Relevant test standard A1 BS EN ISO 1716 BS EN ISO 1182 A2 BS EN ISO 1716 BS EN ISO 1182 BS EN 13823 B, C, D BS EN ISO 11925-2 BS EN 13823 E BS EN ISO 11925-2 Flammability limits This refers to the range of compositions for either fixed pressure or temperature within which a particular explosive reaction is possible when ignition from an external source is availed.

This can always take place even when the substance mixture is very cold (Department of the Environment, 1992). The flammability limits are always given in terms of concentration of the fuel mainly by volume at a specific level of either temperature or pressure. A good example is when there is a lean flammability limits for jet A for the aviation kerosene in the air at the sea level refer to its concentration by volume or its partial pressure of about 0.7%. The rich flammability limits is just about 4.

8% by either its partial pressure of volume (Department of the Environment, 1992). The limits of flammability are not absolute, they depend mainly on the strength and the type of the material of the ignition source. According to studies done on flammability limits of hydrocarbons, they have shown that the stronger the stimulus of the ignition source, the leaner the mixture that can be ignited. The limits of flammability depend mainly on the type of atmosphere, the temperature and the atmospheric pressure.

An example is that the limits are much wider with oxygen as compared with that of air (Great Britain.

Read More