Air Handling And Water Systems Of The Building

Exhaust fan

Discuss about the Air Handling And Water Systems Of The Building.

There are some considerations that should be taken into account when using an exhaust fan include:

Exhaust fans that are not necessary to be shut down should be provided with electrical supply from a clearly labelled devoted main switch.

The opening should be protected with a fire damper together with smoke damper and the exhaust fan should stop functioning during fire mode (Australia, Australian Board 2009).

The exhaust fan should be installed and used according to the operating and installation instructions of the manufacturers.

The exhaust fan should be inspected and reviewed by fire authorities and local building to determine compliance with applicable fire and building codes.

Microbial Control: Under the Air handling and water systems of the building, there is a provision regarding any room within a building is demanded by the Building Code of Australia to be ventilated with outside air by the use of the mechanical system. This is to prevent providing a condition that may favor the growth of microorganisms such as extreme moisture in the room.

Safety regulation: Bathrooms are normally cleaned with chemicals that are very aggressive which may result in numerous health issues when inhaled. These chemicals can easily be eliminated through the exhaust fan (Australia, Building Board 2015).

Evaporative cooling device is a device that cools air through water evaporation due to the large enthalpy of vaporization of water by the use of thermal energy in the air, leading to a lower temperature of the air. The dry air temperature significantly drops through the transition of phase to water vapour from liquid water. This cal, result in cooling of air by use of less energy compared to refrigeration (Burke 2011).

The evaporative cooling device requires frequent maintenance compared to other systems of cooling such as refrigeration. This is because it builds up mineral and salts deposits which have to be eliminated especially in areas of hard water. Since this device uses screens, nozzles, blades, and wet pads for dispersion of water into the air, these surfaces may become a breeding ground for bacteria, mildew, and mould in case the device is not regularly cleaned. The evaporative cooling device is also climate dependent since it needs to operate in a dry climate. This device also requires a constant supply of water and cannot be an effective device in regions where there is the scarcity of water (Gupton 2012).

Regulations regarding exhaust fans usage

Pressurisation is the application of pressure in a given environment or situation. Pressurisation process is normally applied in cabin pressurization, where conditioned air is pumped into the cabin of a spacecraft or aircraft so as to enable a comfortable and safe environment for crew and passengers flying at high altitudes (Burke 2011).

Comfort zone: Can be defined as a condition of mild that articulates contentment with the thermal environment and it is evaluated through subjective evaluation. The human body produces extra heat into the environment for continuity of its operation such that the transfer of heat is proportional to the difference in temperature (Burke 2011).

Climate Control: This is the maintenance of working environment through ventilation, cooling, and heating by use of energy efficiency ways such as using the mechanical ventilation system or natural ventilation grills (Gupton 2012).

Chiller Unit: This is a system used in generating cold water for air conditioning by removing unwanted heat from the structure. Air cooled chiller unit uses fans to blow cool ambient air over the condenser to eliminate heat from the system (Burke 2011).

The air-conditioning plants are normally positioned on the roof of the building since the roof is the ideal position for fresh air intake and heat rejection to the atmosphere. The cooling process is normally noisy, and releases humid and hot exhaust air, hence the best position for the plant is on the roof (Australia, Australian Board 2009).

Air-conditioning is one of the most significant factors for maintaining the quality of healthy indoor air inside the building and the Building Code of Australia (BCA) demands that any room occupied within a residence should have proper air-conditioning with outdoor air. A room within a building is demanded by the Building Code of Australia to be conditioned with air outside by the use of the fan or other mechanical systems that comply with Australian Standard AS1668.2 in case natural ventilation is not provided (Australia, Building Board 2015).

Air conditioning is a system that is made of cooling/warming mechanism and ventilation which takes the air from the inside. Warms or cools it, and conveys it back to the structure. The function of air conditioning is to warm or cool that air to an appropriate temperature that is required so as to ensure the comfort of occupants.

Mechanical ventilation is a system that enables movement of air in a circle by taking the air that is in the structure, and without making any alterations to the air, the system mixes it with the fresh air from outside since the temperature of the air exterior is lower than the inside one, and then circulates the mixed air and fresh back into the structure (Codes 2011).

Evaporative cooling device

Some of the factors that affect the airflow in a space include:

Heat: Presence of heat in a space affects the airflow since hot air tends to rise while cold air tends to remain below the space.

Presence of moisture: Presence of moisture in the space may result in condensation of the moist air.

Design of the space: The design and shape of the space in which air is flowing affect the movement and speed of air as it flows (Codes 2011).

External fire hydrants should be situated in a position that enables access to the pedestrians to the building for the fire brigade or when installed as a feed fire hydrant within 20m of a handstand such that when a appliances of fire brigade for pumping is linked to it, all building portions should be within range of a 10m hose stream, delivering from a nozzle at the terminal length of 60 m of hose placed on the ground (AS2419.1).

Fire appliance hardstand areas and access; The fire appliances should be located on a site adjacent to fire brigade booster connection, feed fire hydrants, and water storage tanks. A minimum height clearance for all fire appliances of 4.20 m is acceptable under service bridges and pipelines. The fire appliance access way should have a minimum of 3.5 m, however, for large isolated building, the entire perimeter vehicular access should have a minimum of 6m throughout (International 2010).

The fire services water has large diameter pipework compared to the ordinary water reticulation since this pipework is designed to operate at pressures between 800kPa and 2000kPa due to their wide diameter ranges of 89mm to 127mm. These wider diameters and high pressures are to satisfy the flow requirements. This range of pressure can easily bust the normal water pumps which have smaller diameters and cannot withstand this high pressure.

A sprinkler system is made up of a nozzle coupled to a pipe network and mounted beneath the ceiling of a building. This system has a minute glass bulb with water in it. This bulb usually prevents the water flow. In case of fire, the liquid in the bulb becomes hot, and then expand resulting in shattering of the glass bulb which acts as an obstacle to the flow of water. The water from the network pipes can then spray from the sprinkler. This system is activated automatically in case of fire through expansion of water in the bulb unlike fire hydrant which has to be operated by trained personnel manually (Burke 2011).

Limitations

Sprinkler systems should have a separate water supply which may be a dedicated gravity tank to provide sufficient, reliable, and flow of water since the sprinkler system is designed to apply water at numerous degrees depending on the risk being sheltered. When this uses common water supply, then there can be fluctuations due to may factor such as increased water consumption in the house or shortage in water supply, this fluctuation will affect the performance of the sprinkler system since the water supplied to the systems may be insufficient to put out the fire (Gupton 2012).

There are four different types of sprinkler systems currently with reference to Australian Standards, these include:

A deluge sprinkler system: These categories of fire sprinkler systems need a heat or smoke detector like the system of pre-action. The system has an open nozzle that can be applied in case or presence of the hazard. This sprinkler system is normally used in case of presence of flammable liquids on the building such as in industrial sector where there are numerous flammable liquid tanks.

Wet pipe fire sprinkler systems: This type of system constantly have water in them to enable quick recovery to the fire and this is the most common sprinkler type used installed in houses in Australia. This system has low maintenance and is also cost-effective. This type of sprinkler system is normally applied office or high-rise buildings with few floors (Gupton 2012).

Pre-action sprinkler system with filled water and air: In this sprinkler system, water and air are permitted to pass through when smoke detector or alarm goes off. This system requires two triggers to commence the flow of water. This system can be set to prevent spouting of water in case of mechanical failure or false alarm. This type of sprinkler system is normally applied in places where sprinklers are specifically significant when there is real fire so as to prevent water damage from accidental sprinklings such as in data centers, libraries, galleries, and museums (Burke 2011).

Dry pipe sprinkler system: This sprinkler system is comparable to the pre-action sprinkler system since they use air that is pressurized which exits before the escape of water. This results in the delay in discharge of water and it is applicable for buildings with low temperatures to prevent freezing of pipes. This type of sprinkler system is applied in a parking garage where there are low temperatures overnight without heating facilities (International 2010).

Pressurisation

Photoelectric: This smoke detector is the most common detector. The smoke is detected by the use of the principle of light scattering or light obscuration.

Provide early warning. When used in classrooms, it provides adequate time for the students to vacate the building.

Sensitive to visual smoke particles. When used in industries, the fire can be detected even before it actually begins

Detects smouldering low heat fires. This makes detecting very effective when used in the kitchen since it can detect in case of the heat rises above the allowable level (Burke 2011).

High potential for a false alarm when used in the kitchen since it may detect the heat from heating systems and give a false alarm.

It must be cleaned on a regular basis especially when used in industries where it is bound to be tainted by industrial fumes and smoke.

Contaminations caused by dust from classrooms may reduce its sensitivity (Burke 2011)y.

Ionization: This type of fire detector is common uses due to its ability to detect smoke originating from fire especially of fires generating tiny particles during combustion.

It can detect invisible products of combustion. This can be effective when used in laboratories where there can be fire without any fire particles being generated.

Earlier detection compared to other thermal or smoke detector. This is very advantageous when used in public places such as hospitals where there is need of enough time to enable exit of a large number of people within a short duration.

Early detection is also very significant is companies where there is need of quick termination of industrial processes in case of fire since the majority of these processes may promote spread of fire (Australia, Australian Board 2009).

May provide false detection is used where there are solvents that are volatile. This can happen in laboratories where there are many solvents that may trigger the false alarm.

The false detection can also be experienced in industries dealing in volatile chemicals and this false detection may result in shutting down of all the industrial processes.

This alarm system only detects the presence of smoke only and not toxicity. There are fumes that can be dangerous than fire especially in manufacturing companies (Burke 2011).

Flame detector: This is used in the detection of light radiation component of a fire. This component is normally used in areas where explosions or fires are rapidly occurring.

Extremely fast acting. This feature makes it suitable for use in companies dealing with inflammable chemicals.

This component can also be effective in largely populated business premises where there is a need for a quick-fire response to enable fast exit.

This device can also be applied in fuel loading docks to enable fast detection of the fire (Codes 2011).

Expensive: This is the reason why many private industries cannot afford it.

Requires unobstructed field of view. This device is only effective in places where there are no obstacles. An obstacle may lead to failure of the system to detect the fire leading to damages in industries.

Difficult to maintain. The maintenance difficulty is the main reason why many of these detectors have failed in schools and have not been repaired (Codes 2011).

The County Fire Authority in Victoria provides emergency and firefighting services to regional town and rural areas in Victoria. This body provides information regarding fire issues relating to the building design, maintenance, alteration, services, and construction. It also inspects a new building to investigate if the fire safety requirements are in accordance with the Building Code of Australia. The authority provides day-to-day advice regarding the construction activities of the building. After the construction of a building is complete, the County Fire Authority monitor the fire precautions, ensure that the electrical systems are safe, fire-fighting equipment is in position, and escape routes and fire doors are appropriately positioned before occupants can start using the building (International 2010).

Australia, Building Code of. 2009. Australian Board. Perth: CCH Australia.

Building Board. 2009. Australia: Australian Building Codes Board.

Burke, Robert. 2011. Fire Protection: Systems and Response. Sydney: CRC Press.

Codes, Building. 2011. National Construction Code: Building code of Australia Class 1 and Class 10 buildings. Australia: Australian Building Codes Board.

Gupton, Guy. 2012. HVAC Controls: Operation & Maintenance. Perth: The Fairmont Press, Inc.

International, Codes. 2010. Building Code of Australia. Melbourne: Australian Building Codes Board, Standards Australia International Limited.