ACOUSTICAL ANALYSISOF
THE FOUNDRY WORKSHOP BUILDING,
SCHOOL OF ENGINEERING AND ENGINEERING
TECHNOLOGY (SEET),
FEDERAL UNIVERSITY OF TECHNOLOGY AKURE,
ONDO STATE.
CARRIED OUT
BY
OLAJIDE FUNMINIYI DEZICK
ARC/09/7411
OKUNJOLU OLUWABUNMI ELIZABETH
ARC/09/7409
TO BE SUBMITTED TO THE DEPARTMENT OF ARCHITECTURE
IN PARTIAL FULFILMENT OF THE COURSE ENVIROMNMENTAL CONTROL III
(ACOUSTIC AND NOISE CONTROL)
(ARC 507)
DATE: JUNE, 2014 LECTURER: PROF O. OGUNSOTE
TABLE OF CONTENT
1.0 INTRODUCTION
2.0 GENERAL DESCRIPTION OF THE BUILDING COMPONENTS FINISHES.
2.1THE FLOOR FINISHES
2.2 THE WALL FINISHES
2.3 THE CEILING FINISHES
3.0 ANALYSIS OF SOURCES OF NOISE
3.1 EXTERNAL SOURCE
3.2 THE INTERNAL SOURCE
4.0 PROPOSED WAY(S) OF IMPROVING THE ACOUSTIC OF THE FOUNDRY
WORKSHOP.
4.1 INTERNAL NOISE
4.2 EXTERNAL NOISE
5.0 CONCLUSION
6.0 REFERENCES
1.0 INTRODUCTION
Acoustics is the science of sound. It is primarily aimed at enhancing speech intelligibility and
music clarity in an enclosed space.
Noise is one of the most common health hazards found in the workplace. Exposure to too
much noise can cause noise induced hearing loss, which has been the most prevalent
occupational disease for the past decades. Many countries have introduced legal obligations and
guidelines requiring employers to protect their employees and others from exposure to excessive
noise. These legal aspects set up the desired steps of a comprehensive prevention management
system to achieve reduction in risk due to exposure to noise. This stand by several employers
shows how imperative it is to know the acoustical state of any industrial workplace, therefore
this paper has been prepared to assess and analyze the acoustical state of the foundry workshop,
school of engineering and engineering technology, federal university of technology akure,ondo
state.
2.0 GENERAL DESCRIPTION OF THE WORKSHOP.
The workshop is rectangular in form. It is a single and free standing building with no
adjoining building or facility connected to it. It is located at oba nla part of FUTA ,near the
school library , engineering workshop and the academic building. The premise of the building is
partially surrounded by shrubs and trees.
It possesses a special foundation (probably because of the potential vibration resulting
from machines which the foundation will be subjected to).At the corners of the walls, instead of
the usual reinforcement concrete column, used was a stanchioned steel bar connected to the
foundation .The walls are made of hollow sandcrete block. The windows are small
(600mm*600mm wide), the windows are glass louver blade windows and raised to a
considerable height. It has three doors, the biggest serving as the main entrance while the
remaining two serves as the exit doors, these doors are all made of steel. The roof of the building
is made of steel as the roof trusses while the roofing sheet is made of long span aluminum
roofing sheets.
Location map of the foundry workshop
Floor plan of the foundry workshop.
Approach elevation. Left-side elevation.
Rear elevation right-side elevation
2.1THE FLOOR FINISHES
The floor of the building is left unfinished. Floor screed is the only floor material
that was used. This floor screed, generates lesser noise compare to when finishes like
terrazzo are used.
Picture showing floor left bare, with the floor screed as the finishing.
2.2 THE WALL FINISHES
Wall surfaces affect the level at which sound is absorbed, transmitted and reflected. The
walls are made of sandcrete hollow block and finished with emulsion paint.
Picture showing interior walls finished with emulsion paint.
2.3 THE CEILING FINISHES
There is no ceiling used, rather the roofing sheet and trusses serves as the ceiling.
More so the roof is constructed in a manner that will help to trap the noise being
generated by the workshop. With the roof serving as the ceiling, reflection of sounds in
the workshop has actually indirectly been enhanced through the design, which is not good
enough. The steel trusses are prone to generating noise when subjected to vibration they
should not have been exposed, acoustic materials could have been used to cover the
trusses to reduce the level of reflection of sound.
Picture showing the interior of the workshop with no ceiling.
3.0 ANALYSIS OF SOURCES OF NOISE
The acoustic condition of the workshop is affected by various factors which range
from external to internal factors i.e. noise is generated from both external and internal sources.
3.1 EXTERNAL SOURCE
External sources of noise include:
i. Noise generated from the car park which is located close to the workshop.
Picture showing parking spaces located at the front of the workshop which is a source of external
noise generation.
ii. Traffic from the adjoining
road coming from the other part of the school also contributes as source of
external noise.
iii. Noises are also generated from adjoining buildings e.g. the academic building
located close to the workshop.
Analysis of external noise
3.2 THE INTERNAL SOURCE
Major internal noise in the workshop arises from the machines and the handy tools during
use.
Noise generating machines includes;
i. Generating plant: this is the alternative source of energy when there is no
power supply from the power supply authority. It generates the highest level
of noise in the workshop of about 70dB.the plant is placed in the workshop
which makes its adverse effect more manifested.
Picture showing the generating plant
ii. Pressure furnace: these are two in number, the first being the compression
pressure furnace-which uses diesel for its fire supply- and the second is the
gas pressure furnaces which produces fire for heating of moldings by gas
pumping with pressure to ensure continuous supply of the fire. They both
generate noise during operation by the fire, whenever it is burning ,which is
usually with pressure. The noise generated by this furnace is around 40dB.
Compression pressure furnace.
Gas pressure furnace.
iii. Rotary furnace: This is the biggest of all the furnaces in the workshop. As a
result, it generates more noise than the other furnaces. Its purpose like the
other aforementioned ones is to produce an uninterrupted supply of fire for
heating. During the process of fire supply or heating, a handful amount of
noise around 56dB is generated.
Rotary furnace.
Other noise generating machines includes;
Polymer extractor
Grinding machines
Other noises are generated by hand-held tools like; hammers (generates noise during
hammering), hacksaws (noise generated during cutting) and files (generates noise during filing)
Hammering. Cutting and filing.
3.0 PROPOSED WAY(S) OF IMPROVING THE ACOUSTIC OF THE FOUNDRY
WORKSHOP.
4.1 INTERNAL NOISE
The foundry workshop is an existing work place. Therefore noise control
method of an existing workplace is best to be applied. The best method is
hierarchy of control.
The hierarchy of control can be divided into:
Elimination:
Substitution
Isolation
Engineering control at source and in the transmission path.
Noise is a by-product produced during a transfer of energy, when some of the energy is not
directly converted into useful work or into waste heat. The ways to control noise are:
reduce the amount of sound energy released;
divert the flow of the energy away from the receiver; or
Protect the receiver from this energy.
Elimination
Elimination is the first step that is usually considered when addressing exposure to noise at a
workplace. After a critical examination of all existing processes it may be possible to eliminate
the exposure entirely by changing one or more operations. For example, high quality welding
eliminates or significantly reduces the need for grinding.
Substitution
This involves substituting quieter processes for noisy ones. A properly designed purchasing
policy that incorporates the "buy quiet" concept is often the best and most cost-effective way of
controlling noise exposure. It also minimizes the need for noise control later, which often can be
very costly. A decision on the maximum acceptable noise emission levels from new equipment
should be made before purchasing. This decision should take into account the organization’s
noise policy and the existing noise levels in the area where equipment is to be placed.
Isolation
Isolation means separating noise sources from people involved in the work or others standing
nearby. It could mean relocating the noise source or relocating the operators or others to
positions away from the noise source. For example, by doubling the distance from the source
inside a workshop the noise level decreases by about 2-4 dB (A), or in the open the noise level
decreases by 6 dB (A).in the foundry workshop for example, the generating plant is installed
inside the workshop. In cases like this the noise in the workshop can be reduced significantly by
housing the plant outside the workshop.
Other methods include;
Administrative control is another method of noise control that as proved to be effective with
little or no cost implications. It is any arrangement that significantly reduces the worker's
exposure time to noise hazards, for example, job rotation, production scheduling, job redesign
and introducing appropriate training on noise.
Provision of personal protective equipment: this involves the use of protective equipments
such as earplugs or earmuffs. It is usually treated as the last line of defence against noise when
noise and administrative control measures are unable to keep the noise levels below the criteria
set for the workplace.
4.2 EXTERNAL NOISE
External noise of the foundry workshop can be reduced by;
i. Screening: this can be done by planting or installing trees, hedges and other
barriers between the workshop and adjoining roads. These barrier(s) will then
reflect any ensuing noise as a result of traffic.
ii. Insulation: this involves the use and application of insulating materials on
external walls so as to reduce the transmission through the walls into the
workshop
5.0 CONCLUSION
Every employee, student or researcher desires to have a good long lasting life and with all parts
of their body (especially Ears) functioning well. Therefore, it becomes imperative to create or
ensure a healthy environment for students, researchers and lecturers who work at or carry out
experiment out at the foundry workshop.
Exposure to too much noise by anybody can lead to temporary or permanent hearing loss.
So, analyzing acoustic situation of any building (especially workshops) becomes crucial. As an
architect, acoustic of any facility should be considered important and monitored during design
stages. Also clients should be advised by architect on the need and benefits of acoustic analysis
of new and existing workplace since this can help boost the productivity of the workers.
6.0 REFERENCES
Professor Olu OlaOgunsote. Acoustics and Noise Control Lecture notes Gary W Seiben, Martin A. Gold, Glenn W Seiben, Michael G. Ermann. (2000); Language Speech and Hearing Services in Schools. Vol.31. pp 376-384 Ivor H. Seeley,(1974); Building Technology, sound insulation pp 276. www.sdngnet.com