Fire Safety Strategy in Constructions - Assignment Example

Fire is a hazard in the proposed building and the entire neighborhood. Fire comes with a lot of consequences whenever it happens that includes a threat to the life of the occupants or their health and safety, could cause damage or property loss and the fire could result in the normal activities in the building being disrupted (Bullen ML, Thomas PH (1978). The prevention and protection measures to be undertaken would be expected to be suitable for the building use and the level of occupancy, the fire risk level for the building as well as the level of duty which is to bestow on occupier (Kingspan, 2009).

The building fire strategy is expected to be an extension of the building’s general health, safety, and environmental policy. The fire strategy's primary objective will be ensuring the provision and maintaining safety in the proposed building which will thus ensure human health and safety as well as safeguarding all the assets in the building.A water mist system is described in the BRE manual as a fixed fire protection system that comprises components for fire automatic detection and actuation of the system, supplying of water, and atomization.

The system design is such that it can discharge a spray of small water droplets and currently there is a lot of debate going on concerning the system about its effectiveness in residential life safety. The system has proved suitability and effectiveness in protecting spaces in ships and is considered to be an emerging technology for life safety building applications of the sea. The system has been reported to be successful when applied to the protection of assets including in electronic equipment, machinery spaces, and deep fat fryers, and now are being considered for residential promises.

The main shortcoming that is currently associated with the system is that building control professionals or fire safety officers when seeking approval of the system is the availability of limited information. Normally the approval process is supposed to rely on appropriate system standards being applied. There are not yet published British or European standards components of the system or the system as a whole.

The The water mist system utilizes water in controlling, suppressing or extinguishing a fire. In the system we have automatic nozzles that are attached to piping system that contains water and then connected to a water supply. During its operation, the system discharges a cone shaped spray comprising of smaller water droplets which fills the protected zone with mist. in some water mist systems there are additional additives and gases that are discharged. For an effective water mist system there should be generation, distribution and maintaining of a concentration of small droplets which are to be sufficient for the protection of the fire risk for a relatively a long time so as to ensure that the objective of protection is met.

This can be achieved through maintenance of the desired flow characteristics at the nozzle for correct duration. Correct positioning of the nozzle is also vital in ensuring the intended space is fully covered and there is minimum wastage of water attributable to the spray colliding with solid surfaces such as cupboards, beams and walls. Shutting down airflows such as those from the ventilation systems so as to ensure there is minimization of water mist loss from the volume under protection may be required.

Design It is required of the system contractor to have detailed criteria upon which the water mist system is to be based. This include: fire control; fire control objective and duration of water mist protection. Fire control mechanisms For a water mist system, when we have a fire incident, there is a heat sensitive quick response glass bulb that is used in actuating the system. This means that at the time of actuation for the case of a residential building the fire is likely to be well established at which point the mist control may be appropriate.

In the water mist system there is also a possibility of using other forms of detectors. This being an automatic system it can be seen to be more appropriate for the case of a residential building such as the 25m high flat which has a single stair where the residence might not be alart during the time of fire or they might be alert in one of the rooms which the area where fire is originating nobody may be present. After the system being actuated the water droplets that is discharged by the system can penetrate the fire with the intention being reduction of the temperature, radiative heat and the concentration level in the area surrounding the fire.

In the remaining areas of the room protection is achieved through cooling of the hot fire gases and smoke and in some cases through the potential combustible fuels in the room being wetted. Bearing in mind that water mist primarily doe not extinguish through direct wetting of the solid fuels in a space, the impact it has on a deep-seated fire may be slow. Also in case where there are small fires or where the fire is shielded extinguishing may not be possible owing to the fact that the system sensors by not be close enough to sense the fire.

Fire control objective In a water mist system the design fire control could be fire extinguishing. This would involve sharply reducing heat release rate which could then lead to flaming or smouldering fire being eliminated. The second objective is suppression/control of the fire. This is to involve a steady reduction in the level of heat release rate which would result to a lower controlled level of burning/limitation in fire growth and the structure being protected through the objects being cooled, cooling the fire gases or by the adjacent combustibles being pre-wetted.

Duration of water mist protection In the BRE manual for water mist system it is recommended that there should be selection of a minimum duration of water supply that is appropriate for each project owing to the fact that no standardized value is currently available. It is suggested that the minimum duration of water supply could be borrowed from those of the sprinkler systems for similar premises for our case a residential apartment Typical examples involving sprinkler systems are as follow: Domestic – duration in excess of 10 minutes for BS 92515 sprinkler systems Residential – time duration of 30 minutes for BS 92515 sprinkler systems or in excess of 60 minutes for the case of BS EN 128453 or BS 5306 Part 24 sprinkler systems.