Advance Design Project:Fire Safety Engineering - Assignment Example

? Advance Design Project Fire Safety Engineering [Pick the Part Ventilation Ventilation has basically been adopted as a hygiene necessity of fulfilling the basic criteria of living in a safe- to- breath- in environment. The acronym HVAC is a sub discipline of mechanical engineering and it stands for Hearing, ventilation and Air Conditioning. The basic purpose of ventilation is to preserve the quality of air (Dr.Sam C.M. hui, 2011). The major purpose of ventilation is basically as follows: Maintenance of human level comfort and their health related factors. Provision of sufficient oxygen for the sustainment of their lives and or of the livestock. Provision of sufficient oxygen or pure air for the healthy continual of processes. Removal of respiratory products and body odor. Removal of harmful elements and contaminants. Removal of indoor generated heat. Creation of air movement that can give the feeling of freshness. For the removal of indoor pollution. Perspective and analytical procedure as indicated by health standards of ASHARE standard 62.1 and CISBR guide 2. Some countries have regional building regulations that require the incorporation of ventilators. For instance, Hong Kong building ventilating system regulation Chapter 123J. Natural ventilation Natural filtration is believed to be a concept where ventilation is conducted naturally through a temperature difference mechanism. This mechanism is operated through the wind and temperature difference mechanisms (Gord Cooke, 2012). As per the definition, natural filtration and ventilation is a reliable source. There however have been a number of reservations and research environmentalists have spotted flaws with this ventilation process. In their view point, in reality this is not at all a reliable source, especially in case of adequate of airs to maintain a good air quality (Dr.Sam C.M. hui, 2011). Mechanical Ventilation Mechanical filtration is the movement of air through a building using fan power that has the ability to control the air flows (Johnson P, 2006). They either are unbalanced or balanced in nature. The unbalanced system functions in such a way that at a particular instance, air is either supplied or exhausted, whereas as per the balanced principal, air is supplied and extracted both simultaneously at the same time (Gord Cooke, 2012). Design principles of Mechanical Ventilation Exhaust must be close to the point of pollutant generation. It should ensure effective local extracts. It should pure air to the breathing zone. It should have access of applying the air to the clean areas. More extract should be from the dirty areas. The system should be scheduled such a way that it transfers the air from clean to dirty means. It should be highly competent and effective for the extraction of ventilation through commercial kitchens, toilets and bathrooms, the underground car parks, factories or industrial buildings and localized industrial extraction. It should have equally effective supply ventilation that means ventilation should be used to ensure adequate supply of outside air. For instance, in boiler house ventilation. Industrial ventilation is equally important in this aspect. It is an important method to reduce employee exposure to airborne contamination. In fact, many industrial laws have this as a mandatory condition. It can either be done through dilution system that is used to reduce the concentrations of contaminants produced or released in a workshop area just simply by dwelling with the air particles of the air (L, 2011). Or it can be done through local exhaust ventilation (LEV) where it captures or contains contaminants as their source before they can easily escape and get scattered in the workplace environment. Energy implication and effective ventilation through heat recovery, demand controlled ventilation (DCV), user control ventilation and through the ventilation system balancing. Examples of Design principles of Mechanical Ventilation for Corridor Installation BRE Smoke Shaft BRE smoke shafts are closed at the bottom and built with a 3m square builders work shaft. Zoned fire alarm systems are either interfaced or otherwise linked to dedication detection system, equipped with 1.5 m square opening vent at each floor. As per the activation based upon need, the AOV’s from all the three locations, i.e., on the fire floor, on the head of the smoke shaft and at the head of the firefighting stair must open. OS2 Control System These are networked fire alarm arrangements that can fulfill the simplest standalone system. They are operated with 24 dc motor and can function as a control network in its own right. Why Building Corridors should focus on Mechanical Ventilation There essentially are three problems with natural ventilation that have been repeatedly spotted and talked by a lot of research and environmental analysts (Johnson P, 2006). Firstly, the power and forces used for creating infiltration are tracked to be totally variable in nature. And this infiltration can only occur when there at least have been two holes in the building envelope (Gord Cooke, 2012). Thus, all type of house, even those classified as the tighter houses have leak holes although they naturally hold lesser infiltration. The common driving forces are: Wind Effect Mechanical Effect Stack Effect Under Wind effect, air comes in from the windward side and exactly leaves from the leeward side. Under the Mechanical effect, exhaust fans and other mechanical appliances are used to induct air inside the houses. The force air mechanical fans although distribute air all across the house, but at the same time cause little positive or negative pressure across the exterior walls and hence, contribute towards inducing ventilation (Mechanical Ventilation, 2010). Stack effect, also known as the temperature or convection effect, is operated by a system where warm air rises and cool air falls. In colder areas, where mechanical ventilation does not exist, stack ventilation is one of the most reliable, consistent, relentless and persistent airflow operations. When the temperature inside the house is higher than the temperature outside the house there is expected to be infiltration at the bottom of the building (Dr.Sam C.M. hui, 2011). The quantity of the flow of air is highly dependent on the size and locations, the variation in the temperature in and outside the building and finally the height of the building. If the building stands on a tall height, it is most expectedly colder inside and has a greater flow (Term paper Wear House, 2002). Building corridors that are design enabled and are equipped with extraordinary fittings such as revolving doors make up air systems that throw air into the building. Thus, while a corridor with a lot of leakage might get enough ventilation, at the other hand too much ventilation on cold and extreme summary days can cause huge problems. Stack pressure of 50 Pascal during colder and at times calmer days are common prevalent in corridors that are built with 30 story buildings (Mechanical Ventilation, 2010). This situation is equitable to a windy day. As well, HVAC concerned environmentalists think that with a high demand of air conditioners in the market, people have become much lesser inclined towards their desire of opening the windows or inhaling fresh air and hence there become much lesser chances of a proper cross ventilation system (Gord Cooke, 2012). Building corridors with large leakage areas dramatically also had the worst air quality. This is very important to be noted by architects who design large buildings with the assumptions that air leakages are healthier than tighter homes. It clearly shows that although it does not result in poor air quality it does indicate natural infiltration cannot be relied upon to maintain good quality. Typically, buildings with air leakage problems are mostly poorly constructed. It literally means water leakages and other defects resulting in air quality problems. The second biggest problem with natural air filtration is that it becomes very difficult to see and control where the air actually enters the building and how it gets surrounded and distributes itself. And since the forces driving the mechanism keep altering constantly, the holes made in the building envelope become the air entry points, while under certain circumstances they might also become air exhaust points (Kotani, 2006). In fact, ventilators labeled as combustion air inlets that are actually architected and designed on the leeward side of the building actually serve as air exhaust vents Computation Fluid Dynamics System (CFD) standards. The same way, buildings with chimneys located on the exterior side would be colder and their corridors would equally be cool in atmosphere during cold and calm days. It is generally expected that the air would go up in a chimney, it in fact, according to the nature, travels down in a cold chimney, especially in the cases where chimney is connected to a building with lots of air leakage near the building top. The air leakage patterns result in fresh air that enters the building corridors through old valve cavities (U.S. Department of Health and Human Services, 2011). Again, these cavities lead towards exhaling stale air particles since they are full of molds and other contaminants that cannot be viewed by naked eye. And again natural leakages are the weakest to depend upon when especially building occupants are looking for getting fresh air in their bedrooms (U.S. Department of Health and Human Services, 2011). In fact, according to a survey, fresh air quality gets compromised for the bedrooms unless fresh air is not directly transferred to the bedrooms through open windows (Debra, 2011). In the absence of control of inlets that are supposed to bring in fresh air, alternatives have to be looked upon. These alternatives could be mechanical equipment’s such as constantly operating furnace fan to ensure that proper mixing of is required (Dr.Sam C.M. hui, 2011). The third and the last impact is the envelope building effect. Both the natural filtration and exfiltration can largely contribute towards compromising the durability of the building envelope. Attic and other closed store room moisture problems develop during the winters because of the holes in the upper wall assembly and the combination of warm air rises. The same way, leakages of hot and humid summer air into an air conditioned building might as well result in condensation and harming the freshness particles once it also has been through wall cavities (L, 2011). The present day architects have to be educated about the concept of building and constructing tight infrastructures for getting the right amount of ventilation. There are certain key concepts of good mechanical ventilation. These elements of good mechanical ventilation are: The right amount of ventilation to be conducted on regular basis. It has been a standard code requirement since almost past years on board. Other than the local codes of exact calculation, continuous ventilation us estimated at almost approximately 15 CFM per bedroom, with the major or master bedroom at 30 CFM. Exhaust fan or other types of moisture exhausting mechanical facility in the areas where dampness and water needs to be exhausted time and on. Provide proper fresh air with healthy air components that get evenly distributed and rotated all across the areas of frequent relaxations such as bedrooms, drawing room, dining room and the living room. Fresh air distribution is in fact much easier to get done when there is the facility of having control over the inlets of fresh air in the building. The effectiveness of providing faultless and secure air to breath- in is often compromised and negotiated with luxury air that is poor in quality. It is so because exhaust only ventilation systems are used (Debra, 2011). Although furnace fan option is equally helpful and dependable, yet, a typical exhaust fan quality needs to be 50 percent higher in the creation and aiming for effectiveness of a mechanically operated system that guarantees the provision of fresh and healthy air. Alongside, the ventilation systems of heat recovery ventilation units (HRV) that are balanced in nature actually avoid the unhygienic issues of infiltration and exfiltration issues that cause problems in the areas of exterior and attic or store rooms or others closed wall areas. Thus, this shows that natural ventilation is a strong fail and to enable buildings with healthy ventilation, mechanical ventilation is needed. As per environmentalists research view, good air quality audits of all type of houses in Europe and America, be they small or large, new or old, tight or lose, they all need to be equipped with mechanical ventilation for an effective and healthy air to breath-in. The current literature about the requirement of air quality strongly supports this claim. This has created a huge market possibility for all the contractors and architects who work in accordance to the HVAC rules and further are looking for bigger opportunities that they can avail from the people who are more focused on air conditioners. Air conditioners are in fact one of the biggest reasons as discussed above for the use of mechanical ventilation in most of the houses. To get this done safely, the HVAC contractors should survey the existing ventilation capacity of each house or the building that they are working or is under their supervision in lieu of some contract (U.S. Department of Health and Human Services, 2011). They can than offer a good deal bargain to the customers for mechanical ventilation. To the least, good quality washroom fans or the exhaust fans, continuously operating furnace fans enables with strong motor, central exhaust fans, energy recovery ventilators should all be used for the effective building of mechanically ventilated buildings (Kotani, 2006). Purpose of Mechanical Ventilation Systems: Fire engineering provides performance based solution with perspective combinations of BS 5588 series and BS 9999. These are code of practice for fire safety used for design, management and incorporation in the buildings. They require the buildings to be constructed and designed so that it can create appropriate provisions for escape in case of fire from the building to some secure destination outside the building premises. BS 7974 They have to comply with the building regulations of BS 9999 B1, B2, B3 and B4. ADB It works on four main fire safety measures, Fire and safety management. Provisions for escape. Structural protection for escape facilitates. Provision and easy access to fight the fire. Risk profile Concept of BS9999 Guidance on the provision of means of escape and on the means of construction, following are reflected: The nature of the building occupants. Use of the building premises along with its probable growth. The risk associated with that use. Occupancy Characteristics Description Examples A Awake and familiar Occupants Official and Industrial zones B Awake but Unfamiliar Occupants Shops and leisure centers C Ci Cii Ciii Asleep occupants Individual with a long planned Occupancy Managed with a long Planned Occupancy Short Planned Occupancy Individual flat with 24 hrs maintenance. Service flats or Dormitories Hotels and Rest Houses D Under Medical care Occupants Hospitals, Health Care Center’s E Transit Occupants Airport, Bus Stop, Railway station Part 2 Computational Fluid Dynamics (CFD) building designs are made especially for analysis made by building environmentalists designers to calculate the temperature, velocity and other fluid properties of a building prior to its construction (IBC, 2002). It is basically a prerequisite for the designing of 3D buildings. Computational Fluid Dynamics is a good appendix to justify the following building queries: Foe clear sky summer conditions, atrium should be expected to have what type of temperature. Can the supply diffusers be arranged in a sequence that could guarantee adequate air movement? How should the radiator be located that would provide good comfort conditions? Is the natural ventilation system designed adequate enough to be resistant against heat and numbness for the occupants/residents? The local wind velocity would be at effective functioning through which shape of the building? Does the building have any regions of state air? Most effective cooling of equipment can be achieved through which layout of hot/cold design of the server. (NFPA , 2000) For the 15 story building, CFD is an ideal model building strategy to be incorporated since its design enables the data on air flow and temperature distribution in and around buildings. It can be done at the fraction cost which otherwise would have been real piled up. CFD buildings are a careful task since they are taking into consideration geometry and boundary conditions. It enables the fixing of different fire and other security equipment’s such a way that they get accessible and effectively functioning all across the building. The 15 story building we are considering can be equally facilitated with this formula. Fire professionals, who suggest seconds as the unit of time for evacuating the building under fire alert mechanism, think that if fire glows rapidly, the smoke alarm has to be more rapid in spreading the awareness at giving a small time fraction for preparing the rescue operation. The requirement they talk about for spreading the fire alert smoke alarm can be best benefited through buildings that are constructed under the Computation Fluid Dynamics System (CFD) (Zhang, 2006). They have been independently tested against phonics, which confirms their validity to be used for crisis management. For that they have gained fame with contractors since past some years. In fact, they help with analyzing building exhausts that would be let out in the environment. The relation of Computation Fluid Dynamics and the smoke alarm comes under the study of turbo mechanism. The building mechanism based on this strategy directly satisfies the three types of requirements that have been set out by fire applicable authorities. These three smoke management systems include building codes, guidelines and code officials that are totally satisfied by the thermal analysis of the Computation Fluid Dynamics System (CFD) (Zhang, 2006). Smoke management vaguely covers all aspects of the movement of smoke. For instance, the physical features equipment’s and the methods. Basically building codes are the basic initiating zone for recognizing the desire for and the features of smoke management system. The exact building code that applies to a particular category of fire smoke as is difficult. However, the veracity of the smoke resistant 15 story building could be pacified if following mistakes are made: The building codes do not characteristically and directly identify or coincide with the Computation Fluid Dynamics System (CFD) when the floors need to be of smoke resistant identity. Hence, in the absence of CFD modification could be located with difficulty through dampers. Smoke barriers coincide with fire rated construction which is a big problem. The burgeoning industry of thorough penetration fire stopping (TPFS) that assembles fire and smoke detectors by independent testing laboratories (ITL) have issued a typically fire and temperature rating. CFA recognizes these building codes for the rating at penetrations at smoke barrier. Other than certain exceptions, fire dampers are usually required by the duct penetration of fire barriers. And this fire barrier is required to be smoke resistive since certain manufacturers claim to provide a combination of both the fire and smoke dampers which are tightly fitted against smoke leakage. As a matter of fact, many damper classifications are canceled according to the Computation Fluid Dynamics System (CFD) standards if any sealant is used in the annular space. This is so because a damper’s space could be compromised it holds a thermal ability of expansion impeded by the sealant. Computation Fluid Dynamics System (CFD) still requires them to apply sealant around the dampers in specific contradiction of the damper’s classification. Thorough penetration fire stopping (TPFS) are copied and tested under laboratory conditions that do not comply with the practical world. For example, in accordance to this test pipes are expected to be anchored against the adjacent barriers. On the contrary, as per the real world working and Computation Fluid Dynamics System (CFD) standards some piping systems move significantly because of thermal expansion (IBC, 2002). Thus, smoke control methods are either static or dynamic. During the smoke event of a static mechanism, all the fans in the 15 story building would stop functioning. This would simultaneously lead to compartment based smoke management method which holds basic movement of smoke. At the other hand, if the smoke control system is based on dynamic system, all or some of the fans stay operational. They are operated under normal or sometimes specialized zones creating pressurizing under specific scenarios to control the movement of smoke. However, Computation Fluid Dynamics System (CFD) standards can benefit the fixing of smoke control to a good extend for 15 story building (ASHARE Reaesrch project , 2002). But still beyond a particular level even the mechanical engineers fail to provide a control for the smoke if its combustion gets over released. Yet, when looking into the design preparations of smoke detectors to fit in Computation Fluid Dynamics System (CFD) standard building of 15 story, code requirement, owner’s desire of potential smoke option and numerous other options need to be kept in mind (ASHARE Reaesrch project , 2002). Specific Building Arrangement Required for 15 Story CFD Model for Fire Escape Common Areas Emergency Lighting Battery in Emergency Lighting. Smoke detector in interior stairwell. More than 2 fire exits at all floors including the basement. Hallway and corridor exits have to be clear and encumbered. 24 inches wide fire escape staircase. Fire escape stairs to lead to public outlets. Vestibule Key and lock protected mail box. Floors, walls and ceilings to be I good repair in vestibule. Adequate Illumination Illumination Continuous illumination for stairs and hallways. 60 Walt bulbs for stairs, corridors and passageway. Bright and well illuminated sign of direction to emergency fire exit stairs. Building Exterior Building foundations should not have cracked concrete. Mortar between bricks of exterior wall. Tight siding on exterior wall. Window frames and sills should have no cracks or paint leaks or spills. No defect in Eaves, Fascia, Soffits, moldings, ornamental projections and cornices. No stagnant water or poorly gathered water lot. No uncontrollable weeds in yard. Fence boards to be straight and strictly not rotten. Garage in good repair. Roof Water tight roof. No holes or defects in roof gutter or waterspout. Downspout to be properly connected to sewer. Glass skylight to be constructed of noncombustible material and glazed with wire glass and single pane. Stairs Stoop concrete to be solid and not defoliate. Porch with sound floor. Strong and upheld balcony. Enclosed stairway window in sound condition and good repair. No tears or holes in the screen. 30 inches high handrail on stairs. Handrail on both sides of the stairs. (Debra, 2011) Extended Travel Distance Approved CFD distance +/-L1 AFD = 18/45 meters. BS 9999 A2 = 22/55 meters. BS9999 A2 + L1 AFD + High Ceiling = 26/75 meters. BS 9999 + L1 AFD = 25/63 meters. (Johnson P, 2006) Use of CFD Modeling to Justify Arrangements Performance of parametric study to determine the effect of the fire intensity and wind conditions show that the distance traveled by fire band varies almost linearly with wind speed as it weekly depends upon the fire intensity and the diameters of fire brands. The lagrangian trajectory model that takes into account forces of fire drag. Under baseline conditions with no wind, the largest number of firebrands lofted in the range of 1.5. (Gord Cooke, 2012) References ASHARE REAESRCH PROJECT . (2002). Investigation into the smoke particles. DEBRA, D. (2011). Mechanical Ventilation Weaning Potocol. DR.SAM C.M. HUI. (2011). Mechinical & Natural Ventilation . GORD COOKE. (2012). Nficial Ventilationatural vs Arti. IBC. (2002). International Building Code. JOHNSON P, S. J. (2006). Long Term mechanical Ventilation in a Ctitical Care Unit. KOTANI, H. (2006). Cross Ventilation research. L, D. B. (2011). The facts of Long term Noninvasive Ventilation. MECHANICAL VENTILATION. (2010). studymode.com. Retrieved from http://www.studymode.com/essays/Mechanical-Ventilation-414732.html NFPA . (2000). Recommended Practise for Smoke Control System. TERM PAPER WEAR HOUSE. (2002). Weaning from Mechnical Ventilation . Retrieved from http://www.termpaperwarehouse.com/essay-on/Mechanical-Ventilation/43002 U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES. (2011). Retrieved from http://effectivehealthcare.ahrq.gov/index.cfm/search-for-guides-reviews-and-reports/?productid=662&pageaction=displayproduct ZHANG, Z. R. (2006). Application of CFD in shipping. Read More