BIOMECHANICAL BACKGROUND

Fig. 1.1 An employee all glued to the computer doing office work

l. Are the joints in a neutral position? No.

The man’s joints in the lower body parts may be in a neutral position but not so in the

upper parts. Taking a closer look, his elbows are not in a prescribe angle so, in that case,

minimal bending of the wrists is inevitable. And bent wrists mean joints are not in neutral

position.

2. Is the work held close to the body? No.

There are two objects he has to keep close to his body, one is the keyboard and the

other is the monitor. Considerably, the keyboard is ergonomically close enough. While the

monitor, however, is too far that he would have had to make some effort to lean closer just to

see his work clearly. Such movements could ascend stress on muscles and joints, making him

feel uncomfortable as the duration of work stretches.

3. Are forward-bending postures avoided? No.

The forward-bending posture in this particular scenario is a result of the work not held

close to the body. He needed to lean forward because the monitor is not on its rightful place.

Before long the muscles in his back, especially near the back blade, up to the arms will be

strained for the maintenance of the upper body balance is now challenged.

4. Are twisted trunk postures avoided? Yes.

All of his tasks will be accomplished with the computer he is using and is fairly just in

front of him. Therefore he wouldn’t need to twist his trunk whatsoever so his spine will be

comfortable, unless he is going to reach for a stack of paper on the other side of his table.

5. Are sudden movements and forces avoided? Yes. Since his job is merely computer related, basically he is free from sudden movement

and forces.

6. Is there a variation in postures and movements? Yes.

In this picture the man changes position by leaning back. That way he is sitting with his

back straight up, which is a better way to sit. Now joints in his elbow are in a neutral position

causing his muscles and ligaments to relax. But there are no other movements like standing,

walking or stretching. If he does only two postures religiously all throughout, he will eventually

get tired.

7. Is the duration of any continuous muscular effort limited? Yes.

As seen in this man’s activity, the stress is mostly on his elbows because they are bent.

Moreover, as a result of leaning forward more stress is pressed on his lower back. And bending

of wrists adds stress on them too. His sitting position only allows him a limited time when

performing continuously. He would need terminal breaks to ease his muscles and prevent a

rather major muscle pain.

8. Is muscle exhaustion avoided? No.

Because he is not sitting ergonomically, his elbows, wrists, back, and even fingers will

get exhausted in the long run.

Fig. 1.2 Coffee break

9. Are breaks sufficiently short to allow them to be spread over the duration of the task? Yes.

Unlike other heavy duty jobs, say construction worker, an office task doesn’t require

much physical energy. Albeit less physical effort is needed in performing office works breaks are

still a must, but then less number of breaks is suggested too. In offices, they provide very short

coffee breaks for the workers to compensate for the long hours of work.

PHYSIOLOGICAL BACKGROUND

10. Is the energy consumption for each task limited? Yes.

An office personnel’s typical job is more physical-friendly than the other. Basically, they’ll

just type, answer phone calls, carry some envelops and the like. Those would not cause severe

muscular damages or serious body fatigue. So the energy they consume for particular tasks are

generally limited.

Fig. 1.3 An employee taking a stretch after a hard day's work

11. Is rest taken after heavy work? Yes.

Probably after a finishing a toxic staff meeting or cramming to meet deadlines he’s given

a considerate time to rest. He decided to relax his muscle, joints and ligament. Lying down is an

instrument to a good rest.

(Image retrieved from: http://www.profitergonomicsolutions.com/Products.aspx http://www.coffeeservice.com/images/breakroom.jpg http://dhomedecorating.com/wp-content/uploads/2011/02/Lay-Flat-Office-Chair.jpg)

ANTHROPOMETRIC BACKGROUND

12. Has account been taken of differences in body size? Yes.

13. Have the right anthropometric tables been used for specific population? Yes.

The product specifications are as follow:

Width: 28-1/4" x 43-3/8"

Height: 35-1/2"

Weight 62 lbs

Width (when folded): 7-3/32"

Maximum work thickness: 3-1/16"

Maximum working width: 27-9/16"

Working height 35-7/16"

The average hip height of the four populations (British Men and Women, and US Men and

Women) listed in the given Anthropometric Table are considered in this table, since its working

height is more or less 900mm. and can be adjusted up to 14.29 mm. more, almost all people

can work on this table properly without experiencing back strain. In addition, the maximum

Fig. 1.5 Ergonomically positioned tensioning knobs.

Fig 1.4 Festool MFT/3 Multifunction Table offers a portable, ergonomically designed workspace that's ideal for everything from rough cutting to fine sanding and assembly.

Fig. 1.6 Perforated work surface and integrated side rails offer a wide variety of clamping configurations.

working width is also considered (which is equal to 700mm.) for easy reaching and to avoid

awkward tool positioning.

(Images retrieved from: http://www.amazon.com/dp/B002W7TLAY/?tag=muanet-20)

POSTURE

14. Has a basic posture been selected that fits the job? Yes.

The basic posture of the cashier is the sitting workstation with little standing up

(<10/hour).

(Images retrieved from: http://www.ponychair.com/kuvat/kommentti4.jpg http://www.ponychair.com/kuvat/tuotetiedot1.jpg http://www.ponychair.com/kuvat/ergomia1.jpg )

Fig. 1.8 Saddle-shaped pony chair that has no backrest

Fig. 1.7 Cashier who uses a saddle type of chair

Fig. 1.9 Sitting position using the saddle-shaped chair

SITTING

15. Is sitting alternated with standing and walking? No.

But under considerable circumstances wherein the cashier has to lift a heavy object,

he/she must stand in order to gain enough strength to avoid body pain.

16. Are the heights of the seat and backrest of the chair adjustable? Yes.

The height of the chair is adjustable, but there is no backrest present in the saddle-

shaped chair in order to maintain the back straight- which keeps the shoulders relaxed and free

from tension.

17. Is the number of adjustment possibilities limited? Yes.

It is limited from 570mm.-820mm..

18. Have good seating instructions been provided? Yes.

Back should be straight, and the chair and the table should be sufficiently high in order

for the feet are placed firmly on the floor.

19. Are the specific chair characteristics dependent on the task? Yes.

According to the research, New Concepts in Seating (Tiedman, J.), “Excellent mobility -

it is easy to move around on the chair, reach for items, and getting on and off the chair is

effortless. … Fairly adaptable for standing-height work as well.” If the task of the cashier calls for

the need to stand up, it will be easy, and since it has no backrest, reaching through the use of

the hands is made easy.

20. Is the work height dependent on the task? No.

The work height (sitting height of the chair) is dependent on the cashier; the feet must be

firmly placed on the ground.

21. Do the heights of the work surface, the seat and the feet correspond? Yes.

The chair has caster wheels which maximize the mobility, and the chair is saddle-

shaped which improves circulation of blood on the legs and back, and lastly, the feet are flat on

the ground due to right chair height.

22. Is a footrest used where the work height is fixed? No.

The worker doesn’t need to have a footrest because the work height is just all right to the

worker. If the work height is high and the worker is tall, she must use a footrest to reach the

work surface, to avoid reaching higher.

23. Are excessive reaches avoided? Yes.

The most important operations should take place within a radius of approximately 50cm.

So when the worker will have excessive reaches, she will have to bend over or twist the trunk

making her uneasy to do the tasks, in this case, using the right chair for the specific job is

crucial. Since the chair the cashier is using has no backrest, her mobility from reaching things is

not limited.

24. Is there a sloping work surface for reading tasks? No.

There is no need for that because the worker is not reading. But if she has reading

tasks, she must have a sloping work surface for her to read easier and brings the work to the

eye instead of other way round.

25. Is there enough legroom? Yes.

The sufficient legroom must be provided under the work surface. In the figure above, the

worker is able to stretch her legs one in a while when sitting for long periods.

STANDING

Fig. 1.10 Worker alternating her position from standing to sitting

26. Is standing alternated with sitting and walking? Yes.

Tasks which are carried out over a long periods in a standing position should be alternated with tasks which can be carried out while seated. The picture shown above shows that the person can either stand or sit when doing computer works to avoid stress due to prolonged posture.

27. Is work height dependent on the task? Yes.

The figure shows a man doing the roll mats in the table. A new study concludes that standing may increase productivity of the worker.

28. Is the height of the work table adjustable? Yes.

The first figure above, the work table is adjustable, making the worker to be convenient of the tasks she is doing. Making the table adjusted makes the worker do the task when sitting or when standing.

29. Has the use of platforms been avoided? Yes.

The uses of the platforms are avoided. The major disadvantages of platforms are that they constitute a trip hazard, are cumbersome to clean, and hamper transport along the floors.

Fig. 1.11 An assembly man who works on roll mats on the table

30. Is there enough room for the legs and feet? Yes.

There is enough room for the legs and the feet. In the figure, the worker allows himself to be close to the work without bending his trunk because of the space under the table.

31. Are excessive reaches avoided? Yes

The excessive reaches are avoided because there is no use to extend or reach for something. Forward and sideways reaches must be limited in order to avoid having to bend forward or twist the trunk.

32. Is there a sloping work surface for reading tasks? No

A sloping work surface must be use to keep in view the task such as reading, writing, etc. The sloping work surface brings the work to the eye.

(Images retrieved from:

http://www.ergonomicevolution.com/ergonomic_philosophy.html http://ohsonline.com/articles/2003/09/standing-for-comfort.aspx )

CHANGE OF POSTURE

33. Has an effort been made to provide a varied task package? Yes.

Everyone is given variation in tasks and activities so that no prolonged postures occur. And with the workstation provided in the image (below), it gives the workers a variety of ways to work on their task, they can sit and have their feet relaxed on the footrest provided, and type with their hands placed flat on the armrest; or they could stand, having the other foot placed on the footrest and adjust the keyboard height to avoid slouching of the back.

34. Have combined sit-stand workplaces been introduced? Yes.

The task can either be done by standing and sitting as shown in the figure. When the task has to be carried out for a long period of time, the workplace should be adapted to allow the work to be carried out either standing or sitting.

35. Are sitting postures alternated? Yes.

To avoid back pains, the worker may alternate her sitting postures. She can also use different types of chairs, those that are ergonomically designed.

Fig. 1.12 An example of a workplace which provides comfort to the worker

Fig. 1.13 The right position when sitting

36. Is a pedestal stool used once in a while in a standing work? No.

The use of pedestal stool while in a standing work allows semi-supported postures to be adopted, which relieve the stress on legs.

(Images retrieved from:

http://www.thehumansolution.com/neutral-posture-n-tune-sit-stand-chair.html http://www.fitness-programs-for-life.com/images/ChairPostures.jpg )

HAND AND ARM POSTURES

37. Has the right model of tool been chosen? Yes.

The figure shown above shows the proper needling technique, choosing the right tool model for the task makes the joints kept as much as possible in neutral position.

38. Is the tool curved instead of the wrist being bent? Yes.

The tool prevents the bending of the wrist. The bent wrist gives joint pains.

39. Are handheld tools not too heavy? Yes.

Fig. 1.14 Doctor doing surgery with his wrist twisted

The weight of the handheld tools must not exceed 2 kg so it can normally use with one hand. Heavy tools uses two hands, if this so, the worker is less productive.

40. Are tools well maintained? Yes.

In order to contribute to the reduction in bodily stress, the user must maintain his tools. Defective or damaged tools will lessen productivity and it requires greater force. And with proper maintenance, it will also reduce wear, noise and vibration, especially using tools that are needed for hospital operations.

41. Has attention been paid to the shape of handgrips? Yes.

If the whole hand is used to exert a force, the handgrip must have a diameter of approximately 3 cm and a length of approximately 10 cm. When using pre-shaped handgrips that fail the mentioned standard, the fingers are constrained.

42. Has work above shoulder level been avoided? Yes.

The task of needling is below the shoulder level. Work above the shoulder increases pain in the shoulder and joints; it also limits the work because more regular breaks must be taken.

43. Has work with the hands behind the body been avoided? Yes.

Working with the hands behind the body should be avoided. If the work is behind the body, we’ll not see properly what we are doing.

(Image retrieved from: http://www.usra.ca/ugt_nt_ip)

LIFTING

44. Have tasks involving manual displacement of loads been limited?Yes

As seen in the picture, lifting of heavy materials units is purely automated. It shows that

no manual labor is used in performing the task of transporting the units. The significant

advantage of the crane is its ability to allow accurate placement of loads, even in confined

spaces. 

45. Have optimum lifting conditions been achieved?Yes

As seen in the picture, the woman is at the optimum lifting condition because there is no

bending or twisting of the trunk while lifting the materials. It is more stable lifter if the object is

held close to your body rather than at the end of your reach. Also, she has a firm hold on the

object that she is lifting.

Fig. 1.15 Lifting a drum

Fig. 1.16 The woman lifting boxes

46. Has care been taken that any one person always lifts less and preferably much less than 23

kilogram? Yes

As seen in the picture, the woman is lifting the materials with both hands. The woman is

able to lift the box up to that level shown, it may be concluded that the weight of the material is

less than 23 kilograms which is the permitted load. Also, due to the light weight of the box, it is

possible to choose the lifting posture freely. The load should not exceed a few kilograms if it is

has to be picked up far away in front of the body.

47. Have lifting situations been assessed using the NIOSH method? No

  For individuals who cannot fully bend the knees in order to pick up objects some bending

of the spine may be necessary. In these cases, be sure the object being lifting is not heavy and

most importantly, be sure to keep the object as close to the body as possible. The farther the

object is away from the body the greater the stress on the spine.

48. Are the weights to be lifted not too light?Yes

The weight of a load has to be chosen carefully. The loads should not be too light

otherwise more frequent lifting becomes necessary. If individual loads are too light there is also

a danger that several loads may be lifted simultaneously.

49. Are the workplaces suited to lifting activities?Yes

The design of tables, shelves, machines and such, onto which loads have to be placed

or from which loads have to be lifted, must result in optimum lifting conditions being achieved.

50. Are handgrips fitted to the loads to be lifted? No

As seen in the picture, it is wrong that the position of the handgrips such that the load

twists when lifted. Also a load should be fitted with two handgrips so that it can be grasped with

both hands and lifted. Grasping the load with fingers should be avoided because far less force

can be exerted.

51. Does the load have a favorable shape?No

As seen in the picture, the shape of the load is not fitted to the man. The size of the load

must be small as possible so that it can be held close to the body. It must be possible to move

the load between the knees if it has to be lifted from the floor.

52. Have good lifting techniques been used?Yes

Ideally, objects should be lifted via the squat lift. With the back relatively straight, the

knees are bent so that low back stress is minimized. While this does not seem as easy or

natural as simply bending forward at the waist it significantly minimizes the lower spinal stress

which can lead to numerous injuries including intervertebral disc herniation. Also, keep the feet

Fig. 1.17 Wrong position of handgrips when lifting

Fig. 1.18 Man carrying large load

wide apart when lifting the object and be sure to keep the object as close to your body as

possible.

53. Is more than one person involved in heavy lifting?Yes

As seen in the picture, two people are working together because the load is too heavy to

be lifted by one person. The partners must be approximately the same height and strength, and

must be able to work well together. One of them must coordinate the lifting, as this will prevent

unexpected movements.

Fig. 1.19 Good lifting techniques

Fig. 1.20 Two man carrying boxes

54. Are lifting accessories used?Yes

Many lifting accessories are available to help fit and move loads. The different types of

levers, raising platforms and cranes give an example of a special device for lifting curbstones.

(Image retrieved from:

http://www.ferret.com.au/c/Spacepac-Industries/My-T-Lift-electrical-mast-crane-n665502

http://www.123rf.com/photo_8970268

https://fpmwww3.fpm.wisc.edu/safety/occupationalHealth/Ergonomics/BackSafety/

BackCareWhenLifting/tabid/103/Default.aspx

http://www.clipartguide.com/_pages/0041-0701-1713-0645.html

http://www.superstock.com/stock-photos-images/1839R-2787

http://www.low-cost-cranes.com/

Fig. 1.21 Lifing objects through pulley

CARRYING

55. Is the heavy weight of the load limited?Yes

The permissible weight of a carried load is determined mostly by the lifting which

precedes the carrying. If manual lifting of heavy loads (up to 23 kg) is necessary, then it must be

possible to choose the lifting posture freely and the trunk should not be twisted when lifting.

56. Is the load held as close to the body as possible? Yes

To limit both mechanical stress and energy consumption, the load must be kept as close

as possible to the body. Small compact loads are therefore preferable to larger loads.

57. Are good handgrips fitted?No

As seen in the picture, there are no handgrips attached to the box. The load should be

fitted with well-designed handgrips that have no sharp edges.

58. Is the vertical dimension of the load limited?Yes

As seen in the picture, the load is small enough to be able to carry. A person lifting a tall

load will tend to bend the arms to prevent the load from hitting his legs. This causes additional

fatigue to the muscles in the arms, shoulders and back. The vertical dimension of the load must

therefore be limited.

59. Is carrying with one hand avoided?Yes

Fig. 1.22 A woman carrying a limited load

When only one hand is used to carry a load, the body is subject to an asymmetric stress.

The solution is to carry two lighter loads one in each hand.

60. Are transport accessories being used?Yes

Conveyor belts are used in many industries to transport goods and materials between

stages of a process. Using conveyor systems is a good way to reduce the risks of

musculoskeletal injury in tasks or processes that involve manual handling, as they reduce the

need for repetitive lifting and carrying.

(Image retrieved from:

http://youcanbewell.blogspot.com/2010/11/ergonomics-101-proper-lifting.html

http://duofriberg.nu/situation-new-idea-manure-spreader-213-conveyor-chain/

Fig. 1.23 Conveyors used to transport objects

PULLING AND PUSHING

61. Are pulling and pushing forces limited? Yes

When setting a trolley in motion by pulling and pushing the exerted manual force should

not exceed approximately 200 N. Although the maximum possible force required is often

considerably higher, this limit should be adhered to on order to prevent large mechanical stress,

mainly to the back.

62. Is the body weight used during pulling and pushing?Yes

Workers use various pushing and pulling techniques in a wide range of activities, such as:

Using manual carts and trucks Sliding objects such as cartons on flat surfaces (tables, floors, etc.) Operating tools and controls Opening and closing doors Wrapping or enclosing objects in packaging materials

 Injuries due to slips and falls are also often associated with pushing and pulling.

63. Are the trolleys fitted with handgrips?Yes

A seen in the picture, this trolley is fitted with a hand grip that can be used both left and

right-handed.The man is able to push the trolley up to that standard level shown.

Fig. 1.24 Pulling a cart

64. Do the trolleys have two swivel wheels? Yes

65. Are the floors hardened and even? Yes

http://www.superstock.com/stock-photos-images/1570R-118321

I. INTRODUCTION AND OBJECTIVES OF THE STUDY

Every person is unique on his own way, and so does every person’s sizes and built.

When it comes to everyday living it is frequent to find various sizes from clothing to furniture. To

decide for this matter, a deep understanding about variation of body sizes is necessary, and for

this, a branch in Ergonomics called Anthropometry is dedicated to fully establish the differences

of body sizes of every person from every race.

Since it is very crucial for designers to come up with a product that is suited for the

varying sizes of the company’s target market in order to create a very satisfactory output that

will definitely catch the consumers, henceforth, anthropometry is very essential in taking

account of this matter.

Productivity is the number one concern of every company/organization. The equipment

that people use in their work and the suitability of the product design of a company to its

customers affect the productivity of an individual and a company.

As future Industrial Engineers it is imperative to have a basic glance of the different

anthropometric concepts and apply them to a specific product design in a particular population.

This study aims to relate the said concepts to the 3rd year IE students of UST by

measuring the assigned dimensions, namely fingertip height and shoulder-grip length using tape

measure. Once measurements are taken, computations for the mean, standard deviation, and

5th, 50th, and 95th percentiles are required in order to analyze the gathered data and in order for

the group to be able to determine how much of the population can work on the product

comfortably provided with the tolerable range set by the group.

II. RAW DATA TABLE (measurements are in units of inches)

NAME Fingertip Height Shoulder grip LengthCamarillo 26 25.5Divino 22.1 23Eroy 22.2 24.8Ibarra 23.5 24Macabalo 27 25.8Mado 25.2 24.5Miranda 25.2 24Paulin 22.9 24Refuerzo 21.5 22.5Uy 24.3 23.2

Velarde 22.6 24.5

Table 2.1 Raw Data Table of 3IEA boys

Table 2.2 Raw Data Table of 3IEA girls

Table 2.3 Raw Data Table of 3IEB boys

NAME Fingertip Height Shoulder grip Length

Atienza 23.2 23.6

Calagos 24.5 24.5

Chua 24.4 23.5

Conti 23 23.3

Cruz 22.1 23.5

Dauan 22.8 24

Fernandez 25.1 23

Go 22.8 23

Kinol 24.8 24.5

Laureta 22 23.1

Llante 22.9 24.5

Manuel 22.5 24

Moreno 22.8 22

Orcullo 25.2 24

Quibod 22.8 23

Ramirez 21.1 21.2

San Miguel 22 24.5

Sangalang 20.5 20

Tadeo 20.8 23

Villanueva 23.2 23.3

NAME Fingertip Height Shoulder-grip Length

Abadicio 21.2 24.5

Algallar 24.5 26.5

Bautista 27.5 25.5

Cabatingan 25.5 26.5

Calonsag 24 23Concepcion 25.5 24

Esctacio 27.8 27

Fernandez 23.8 26.5

Ilagan 23.8 25.5

Magat 22.9 22.5

Miralles 26 25

Rogero 22.8 24

Sibal 22 24.5

Unson 26 25

NAMEFingertip Height Shoulder-grip Length

Caballes 22.8 22.7

Cano 23 23.5

Clemente 23.5 24

Dizon 22 24.8

Garcia 23.1 23.8

Junio 22.5 24

Kimpo 24 26.5

Luceno 21.5 23

Mangulabnan 23.8 23

Montoya 23.2 24.8

Nael 22.2 25.8

Nicola 21.3 22.5

Pari-an 23.8 23.4

Perez 22.5 22

Raso 25.3 26

Raymundo 23.8 25.3

Valentin 23.8 23.4

NAME Fingertip Height Shoulder-grip LengthAstronomia 23.9 24.2

Table 2.4 Raw Data Table of 3IEB girls

Table 2.5 Raw Data Table of 3IEC boys

Atienza 24.7 24Basco 25.1 24Bautista 24 23.5Butardo 23 22Cabantog 22.9 23Canicula 23.2 24Canoza 24.5 25Cruz 24.5 25.8Ebora 23.5 24Jimenez 24.2 24.3King 23.9 24Leones, F. 22.5 25Lllanto 22.9 24Mabato 24 24.5Marca 23 22.8Monfero 23 23.5Nalupa 23.9 23.2Sacramento 25.5 25See 24 24.8Segismar 26.5 25.8Seraspe 26.7 27Sison 25.2 25.5Torres 24 25

NAME Fingertip Height Shoulder-grip LengthAlada 22.5 22Alejandrino 22.2 22.5Arcenas 22.8 23.2Belocura 21.8 20.5Bravo 23.5 22Calubia 21.9 21.3Cua 23 20.5Dungca 22.8 22.3Leones, B. 22.8 22Lupac 24.6 22.8Panopio 23 23.5Reyes 23.5 21Torres 21.4 21.5Wang 25.8 22.5

III. COMPUTATION

Formulas:

For Mean:

Table 2.6 Raw Data Table of 3IEC girls

X=∑ Xn

n

For Sample Standard Deviation:

σ=√∑ (Xn−¿ X )2

n−1¿

For the P5, P50, and P95 percentile values:

P95=X+1.645σ

P50=X+0σ

P5=X−1.645σ

Mean and Standard Deviations

Male:

1. Fingertip Height

X=21.2+24.5+23.9+24.7+…+24+26+24.3+22.649

=24.17

σ=√ (21.2−24.17 )2+(24.5−24.17)2+(23.9−24.17)2+…+(26−24.17 )2+(24.3−24.17 )2+(22.6−24.17)2

48=1.54

2. Shoulder Grip Length

X=24.5+26.5+24.2+24+…+25+25+23.2+24.549

=24.48

σ=√ (24.5−24.48 )2+ (26.5−24.48 )2+…+ (23.2−24 )2+¿¿¿

Female:

1. Fingertip Height

X=22.5+22.2+22.8+23.2+…+21.4+23.8+23.2+25.851

=22.98

σ=√ (22.5−22.98 )2+ (22.2−22.98 )2+…+(23.2−22.98 )2+¿¿¿

2. Shoulder Grip Length

Equation 2.1

Equation 2.2

X=22+22.5+23.2+23.6+…+21.5+23.4+23.3+22.551

=23.17

σ=√ (22−23.17 )2+(22.5−23.17 )2+…+ (23.3−23.17 )2+¿¿¿

Whole 3rd year Batch (Male and Female)

1. Fingertip Height

X=21.2+24.5+23.9+24.7+…+21.4+23.8+23.2+25.8100

=23.57

σ=√ (21.2−23.57 )2+(24.5−23.57 )2+…+ (23.3−23.57 )2+¿¿¿

2. Shoulder Grip Length

X=24.5+26.5+24.2+24+…+21.5+23.4+23.3+22.5100

=23.81

σ=√ (24.5−23.81 )+(26.5−23.81 )+…+(23.3−23.81 )+(22.5−23.81)99

=¿1.45¿

Percentile Computations: For Male Anthropometric table

1. Fingertip Height

P5=24.17−1.645∗1.54=21.65

P50=24.17+0∗1.54=24.17

P95=24.17+1.645∗1.54=26.70

2. Shoulder Grip Length

P5=24.48−1.645∗1.18=22.53

P50=24.48+0∗1.18=24.48

P95=24.48+1.645∗1.18=26.43

Percentile Computations: For Female Anthropometric table:

1. Fingertip Height

P5=22.98−1.645∗1.17=21.06

P50=22.98+0∗1.17=22.98

P95=22.98+1.645∗1.17=24.91

2. Shoulder Grip LengthP5=23.17−1.645∗1.39=20.89

P50=¿23.17+0*1.39=23.17

P95=23.17+1.645∗1.39=25.45

Percentile Computations: For the Whole 3rd year Batch (Male and Female) Anthropometric table

1. Fingertip Height

P5=23.57−1.645∗1.48=21.13

P50=23.57+0∗1.48=23.57

P95=23.57+1.645∗1.48=25.99

2. Shoulder Grip Length

P5=23.81−1.645∗1.45=21.44

P50=23.81+0∗1.45=23.81

P95=23.81+1.645=26.19

IV. ANTHROPOMETRIC TABLE

(A.) FOR SECTION 3IEA

Dimension P5 P50 P95 Std. Dev.1. Fingertip Height 20.9082 23.864 26.8198 1.82. Shoulder-grip Length 22.5006 24.164 25.8274 1.01

Dimension P5 P50 P95 Std. Dev.1. Fingertip Height 20.7 22.92 25.14 1.352. Shoulder-grip Length 21.4 23.28 24.07 1.14

(B.) FOR SECTION 3IEB

Dimension P5 P50 P95 Std. Dev.1. Fingertip Height 21.29 24.52 27.75 1.962. Shoulder-grip Length 22.76 25 27.23 1.36

Dimension P5 P50 P95 Std. Dev.1. Fingertip Height 21.4 23.06 24.73 1.012. Shoulder-grip Length 21.9 24.03 26.18 1.31

(C.) FOR SECTION 3IEC

Dimension P5 P50 P95 Std. Dev.1. Fingertip Height 22.3 24.11 25.92 1.12. Shoulder-grip Length 22.52 24.33 26.14 1.1

Dimension P5 P50 P95 Std. Dev.1. Fingertip Height 21.08 22.97 24.86 1.152. Shoulder-grip Length 20.45 21.97 23.49 0.93

SUMMARY FOR

Table 2.9 Anthropometric Table for 3IEB boys

Table 2.8 Anthropometric Table for 3IEA girls

Table 2.7 Anthropometric Table for 3IEA boys

Table 2.10 Anthropometric Table for 3IEB girls

Table 2.11 Anthropometric Table for 3IEC boys

Table 2.12 Anthropometric Table for 3IEC girls

Table 2.13 Summary for the whole 3RD YEAR (males)

THE WHOLE 3RD YEAR

Dimension P5 P50 P95 Std. Dev.1. Fingertip Height 21.65 24.17 26.7 1.542. Shoulder-grip Length 22.53 24.48 26.43 1.18

Dimension P5 P50 P95 Std. Dev.1. Fingertip Height 21.06 22.98 24.91 1.172. Shoulder-grip Length 20.89 23.17 25.45 1.39

Dimension P5 P50 P95 Std. Dev.1. Fingertip Height 21.13 23.57 25.99 1.482. Shoulder-grip Length 21.44 23.81 26.19 1.44

V. APPLICATION

For the fingertip height, the group selected lathe machine since it is required for the third

year students to know how to operate the said machine on their course Industrial Materials and

Processes (IMP). In operating the machine, the carriage handwheel has to be moved in order

for the machine function forward and backward. The said wheel’s height with respect to the

ground (on its normal position) is 24.7 inches. The group wants to find out the probability of the

selected population on using the wheel by maintaining a standing posture, meaning without

exerting too much effort to bend. All students who have a fingertip height ranging from 23 inches

to 26 inches would be able to use the wheel with relative ease.

Table 2.14 Summary for the whole 3RD YEAR (females)

Table 2.15 Summary for the whole 3RD YEAR (all)

Computations (Two-tailed Normal Distribution)

z1=23−23.5661.48

=−0.38

z2=26−23.5661.48

=1.64

P ( z2=1.64−z1=−0.38 )=0.9495−0.3520

( z2−z1 )=0.5975∨59.75%

Normal Curve:

Fig. 2.1 Lathe Machine

Fig. 2.2 Normal Curve

With x1=23 inches, and x2=26inches

Based on the computations given above, only 59.75% of the sample or only 60 students

out of the 100 3rd year students (who acted as the group’s sample) can use the wheel at a

specific height of 24.7 inches with a relative ease wherein the student need not to exert too

much effort on bending his knees or stretching his arms.

For the shoulder-grip length the product to consider is the hazard button of a particular

car. The group measured the distance from the driver’s seat to the button, and the distance is

equal to 24 inches. Although cars are already designed for various body sizes, the group wants

to find out the probability of the 3rd year students to reach for the hazard button at ease with the

given distance of 24 inches. With the said distance, students who have a shoulder grip length

from 23 inches to 26 inches can reach the button without too much bending of the back or too

much stretching of the arms.

Computations (Two-Tailed Normal Distribution)

Fig. 2.3 Hazard button in the car

z1=23−23.8131.44

=−0.56

z2=26−23.8131.44

=1.52

P ( z2=1.52−z1=−0.56 )=0.9357−0.2877

( z2−z1 )=0.648∨64.8%

Normal Curve:

With x1=23 inches, and x2=26inches

Based on the computations made, a probability of 0.648 can reach the hazard button at

ease, provided that the distance of the button from the seat is 24 inches. Hence, 65 students out

of the 100 students can move the button without difficulty.

VI. CONCLUSION

Fig. 2.4 Normal Curve

The measurements of all the 3rd year Industrial Engineering Students in UST range from

20.5 inches to 27.8 inches in the fingertip height and the measured shoulder grip length ranges

from 20 to 27 inches.

After we conducted the study, the group has concluded that anthropometry is a very

important consideration in designing products. In producing items that will be used by a certain

population, the actual range of measurements should be taken note of and considered. In the

carriage hand wheel in the lathe machine, if the designers did not take into considerations the

variations in the fingertip heights of the people, it would only be fitted to few individuals.

Considering the variations, the makers of the lathe machines will add some adjustment

possibilities so that users are more at ease in using the machine. And for the hazard button

used in cars, the distance from the button to the backseat of the car must be fitted to a wider

range of population. Through taking note of the variations of the shoulder grip lengths, the car

makers design this in such a way that drivers are comfortable in their seats, reaching for the

hazard button, not overstretching their shoulders.

We also conclude that, 59.75% of the population, which is the 3 rd year IE students, were

fitted to use the carriage hand wheel of the lathe machine that is present in the Machine Shop of

our building. Also, 64.8% of the said population is fitted in the use of the hazard button in cars.

In OWAS and in RULA, the same person and tasks was under studied. The company is a

beauty parlor named “Stand Out Salon”. Mainly, during the account of observation, the person’s

(Angelito Tuyor - Salon Manager) tasks are the following:

1. Hair cut;

2. Facial;

3. Massage;

4. Hair colour;

5. Blow dry and shampoo; and

6. Shave

The group intended to select the said salon for this study due to the reason that the upper

body of the people who work on beauty parlor is the one that always functions.

Working on a parlor has its own extreme demands like getting exposure on different

temperatures and working conditions.

I. Ovako Working posture Analysis System(OWAS)

Fig. 3.1.1 A worker doing facial

A. TASK DESCRIPTION

The picture shown above is giving a facial treatment to a customer which is one

of his tasks. This task was chosen due to the fact that this treatment lasted for an hour.

Although a minimal force was only exerted on executing this task, the fact that the

worker is most of the time standing, and the arms have no support whenever doing a

certain task could result to fatigue in the legs, arms, back.

It must be clear that the observations that were done using OWAS and RULA are

the same. Henceforth, the task that is stated above is just one of the tasks among those

which are being performed during the 4-hour observation.

FLOW PROCESS CHART (FPC) – OWAS

Table 3.1.1 Flow Process Chart

B. WORK SAMPLING

N=3.84× pq0.0025

(Equation 3.1)

In the equation for getting N, “pq” stands for the probability of working and idle moments

from out of the initial random observation which is 30.

Out of the 30 random observations, below are the proportions of p and q:

p=2830

q= 230

And now, solving for the N using the formula above,

N=3.84×

2830

×230

0.0025

N=95.57≅ 96 actualobservations

C. DIFFERENT POSTURES – ACTION LEVELS

The legend shown below will be the basis of judgment for the conclusion of

working postures of the Trunk, Arm, Lower Body, and Head and Neck that were

previously gathered from the different postures observed.

Legend    

  Acceptable  

  Slightly harmful

  Distinctly harmful

  Extremely harmful

a. Trunk Posture

Fig. 3.1.2 Conclusion of working postures of trunk, arm, lower body, and head and neck

The picture shown above is the usual posture of the subject based on the

96-random data gathered from the observation. Below is a table that shows the

frequency of the trunk’s posture, starting from neutral, bent forward, twisted, and

bent and twisted.

Frequency Percentage (%)*Neutral 62 64.58Bent Forward 10 10.42Twisted 15 15.62Bent and Twisted 9 9.38Total 96 100

Fig. 3.1.3 Trunk Posture

Table 3.1.2 Frequency of the trunk’s posture

Fig. 3.1.4 Trunk Posture- Action Levels

The bold black marks in the diagram represent the percentage of time the

subject is in the said posture. By simply referring to the diagram alone, it is

evident that the trunk posture is 95% acceptable during the period of observation.

b. Arm Posture

As seen in the image above, the positioning of the subject’s hands are in

awkward situation, and if it continues for quite a while, the subject may

experience fatigue in the wrist part and in the upper arm. A table below is

presented for the frequency of the arm postures that were observed.

Frequency Percentage (%)Both arms below shoulder

73 76.04

One arm above shoulder

20 20.83

Both arms above shoulder

3 3.13

Total 96 100

Fig. 3.1.5 Worker’s arm posture

Table 3.1.3 Frequency of the arm posture

Fig 3.1.6 Arm Posture- Action Levels

The diagram above shows that 100% of the time the subject’s arm

posture is acceptable. Thus, the picture shown above (Image 3) which is an

awkward posture for the arms is not a frequent event on the subject’s tasks.

c. Lower Body Posture

The lower body posture consists of 6 categories which are:

1. Sitting (A);

2. Standing with two feet and legs straight (B);

3. Standing with one foot and legs straight (C);

4. Standing with one or two feet – knees bent (D);

5. Kneeling (1 or 2 feet) (F); and

6. Walking (G).

Frequency Percentage (%)A 0 0B 90 93.75C 0 0D 4 4.17E 0 0F 2 2.08Total 96 100

Fig. 3.1.7 Worker’s lower body position

Table 3.1.4 Frequency of Lower body posture

During the 96 random observations taken, majority of the subject’s lower

body posture is standing. Common to his tasks is the standing posture, even

during giving a facial treatment. Unlike other salons that offer such treatment,

the employee is given a seat. And it is known that too much repetitive posture

results to fatigue which leads to a 14% slightly harmful. To aid this result, it

would be best for the employee to be given a seat for some services, such

as, facial treatment, hair cut when the customer is petite, and services that

take a very long time to finish like ironing of hair.

d. Head and Neck Posture

The picture above is the same picture of Image 3, and in this picture, the

posture of the head and neck is visible. The working postures for the head

and neck are usually in neutral position, bent positions (forward, side, and

Fig. 3.1.8 Lower Body Posture – Action Levels

Fig. 3.1.9 Worker’s Head and neck posture

back), and twisted. Below is the table of frequency and percentage of the

postures that the subject had during the observation period.

Frequency Percentage (%)Neutral 50 52.08Bent forward >20 deg. 13 13.54Bent side > 20 deg. 32 33.33Bent back >20 deg. 0 0Twisted > 20 deg. 1 1.05Total 96 100

Summary of the OWAS results:

POSTURE Acceptable

SlightlyHarmful

DistinctlyHarmful

ExtremelyHarmful

Rating

a. Trunk Posture 95% 5% 0% 0% Acceptable

b. Arm Posture 100% 0% 0% 0% Acceptable

c. Lower Body Posture 86.25% 13.75% 0% 0% Acceptable-to-Slightly harmful

d. Head & Neck Posture 86.67% 13.33% 0% 0% Acceptable-to-Slightly harmful

CONCLUSION AND RECOMMENDATION

Table 3.1.5 Frequency of Head and Neck Postures

Fig. 3.1.10 Head and Neck postures- Action Levels

Table 3.1.6 Owas results summary

Based on the results that the group has gathered, it is concluded that the

worker’s posture over time is acceptable to slightly harmful. Meaning, if a certain posture

is maintained over a long period of time, tendency is, the worker will soon feel restless

and might subject to fatigue.

In order to avoid such fatigue and other failures due to the working posture of the

employee, the group has come up with some recommendations that the company

should consider.

1. An employee should have a break time every after work that lasts up to 5

minutes the most before starting another service. It is proven that providing

short break times after a certain work makes an employee more efficient and

productive.

2. Break times should consist of sitting on a couch and resting the head on a

soft cushion. Through this, blood circulation on the back to the head will go

smoothly and reduce tension that it incurred while working.

3. Also, in order to make the arm posture more comfortable, the worker should

at least try to avoid engaging into jobs that exposes the hands into extreme

temperatures. For example, if the worker’s job is to flat iron the hair, then he

should not do a job that deals with getting water, like washing and applying

shampoo to the hair. Hence, if a situation like this would happen, there should

be an employee designated to this specific kind of job.

II. Rapid Upper Limb Assessment(RULA)

A. TASK DESCRIPTION

Image 5 shows another job that subject does, in this image he does a hair cut

service to the customer. The group opted to choose this task mainly because doing

hair cut is one of the most in demand service in their salon. Although giving the said

service lasted only for 45 minutes the most, this task is the most frequent service that

the salon offers.

FLOW PROCESS CHART (FPC) – RULA

Table 3.2.1 HaircutFlow Process Chart

B. WORK SAMPLING

Fig. 3.2.1 Worker doing hair cut

As it was stated beforehand on the OWAS part, the same work sampling is applied for RULA. However, the focus sample of this part is concern about the hair cut service.

C. RULA SCORE RESULTS

Time

Left Upper Body

Posture

L-result

Right Upper Body

Posture

R-result

12:03 2   5  12:05 3   3  12:06 3   3  12:07 3   3  12:11 3   3  12:12 3   3  

12:17 2   2  12:18 2   2  12:19 2   3  12:21 2   3  12:23 2   3  12:29 3   3  12:31 3   3  12:32 2   2  12:34 2   2  

12:36 2   2  12:38 4   4  12:40 4   3  12:43 2   3  12:47 3   3  12:55 2   2  12:56 2   2  

1:00 2   2  1:07 3   3  1:10 3   3  1:14 2   2  1:15 2   2  1:26 2   3  1:31 3   3  1:32 3   3  1:34 2   2  1:36 3   3  1:36 3   3  1:38 3   3  1:40 6   6  1:43 4   4  1:43 7   6  1:46 4   4  1:48 3   3  

1:49 3   3  

1:50 4   6  1:51 2   3  1:53 4   5  1:58 4   4  2:00 4   4  2:05 2   3  2:08 2   3  2:10 2   3  2:12 4   4  2:12 3   4  2:14 4   4  2:14 3   3  2:15 3   3  2:17 3   3  2:17 4   3  2:20 2   3  2:22 2   3  2:28 2   3  2:29 3   3  2:32 3   3  2:33 2   3  2:36 3   4  2:37 3   3  2:40 3   3  2:43 5   5  2:46 4   4  2:48 4   5  2:55 4   6  2:55 4   4  2:57 4   5  3:00 5   6  3:03 5   4  3:04 4   4  3:05 4   4  3:06 4   5  3:08 3   4  3:12 4   3  3:13 2   4  3:14 5   4  3:17 3   3  3:20 3   4  3:22 4   4  

Table 3.2.2 Results based on RULA for left and right upper body

3:24 4   5  3:24 4   3  3:31 4   4  3:34 5   4  3:36 4   3  3:38 4   4  3:40 3   4  3:41 4   3  3:42 2   5  3:43 3   3  3:47 3   2  3:51 2   2  3:54 2   3  3:59 3   2  

ScoresLegend:       L R

Score 1-2

Posture acceptable if not maintained or repeated for long period;

30 14 

Score 3-4

Further investigation is needed, and changes may be required;

59 69 

Score 5-6 Investigation and changes

are required soon;6 13

 Score 7 Investigation and changes

are required immediately.1 0

 

96 96

III. National Institue of Occupational Safety and Health

(NIOSH)

A. TASK DESCRIPTION:

For the NIOSH, the group conducted the study on a Laundry Shop called,

Fabricyle Good Fellow Laundry. The task that the group covered was the lifting of

packages of clean clothes to the rack.

FLOW PROCESS CHART (FPC) – NIOSH

Fig. 3.3.1 Worker lifting packages to the rack

Table 3.3.1 FPC for carrying laundry

B. MEASUREMENT INDICATORS

After the group made measurements for the horizontal and vertical distance,

distance from where the packed clothes are pulled out to the storage area, the degree of

trunk rotation and the lifts per minute the worker can, we are now ready for

computations. The equation for determining the recommended weight limit is as follows:

Recommended Weight Limit = LC X HM X VM X DM X FM X AM X cm

Where:LC= Load ConstantHM= Horizontal MultiplierVM= Vertical MultiplierDM= Distance MultiplierFM= Frequency MultiplierAM= Asymmetry Multipliercm= Coupling Multiplier

Horizontal Multiplier (HM)

The horizontal multiplier is determined from the horizontal distance from the mid-

point between the ankles and to a point projected on the floor directly below the

mi-point of the hand grasps. And the equation is as follows:

HM= 10H

H= 39.37 inches

HM = 1039.37

Fig. 3.3.2 Shows the HM when carrying packages

Equation 3.3.1

HM= 0.25

Vertical Multiplier (VM)

The vertical multiplier is determined from the vertical distance from the floor to the midpoint between the hand grasps. And as follows:

VM = 1- (0.0075|V−30|¿

V= 53.94 inches

VM = 1 – (0.0075|53.94−30|)

VM = 0.82

Distance Multiplier (DM)

Fig. 3.3.3 Shows the VM

Equation 3.3.2

The distance multiplier is determined from the vertical travel distance of the

hands between the origin and destination of the lift. As follows:

DM = 0.82+ (1.8D

)

D= 57.87 inches

DM = 0.82 + (1.8/57.87)

DM= 0.85

Asymmetry Multiplier (AM)

The asymmetric multiplier is determined by the degrees of trunk rotation.

Fig. 3.3.4 Shows the DM

Equation 3.3.3

AM= 1-(0.0032*A)

A= 75°

AM = 1- (0.0032*75)

AM= 0.76

Frequency Multiplier (FM)

The frequency multiplier is determined by the number of lifts per minute

(frequency), the amount of time engaged in the lifting activity (duration), and the

vertical height of the lift from the floor.

The worker at the laundry shop can lift 25 kg of clothes daily. She can do

(on average) 4 lifts per minute given that the packs of clothes weigh from 4 to 11

kilograms. And she lifts the load from a vertical height of 57.87 inches. The lifting

duration is only about an hour or less because other task is done like washing of

clothes. Lifting is done repetitively every after a washing process is finished.

As long as the lifting frequency does not exceed 15 lifts per minute:

Fig. 3.3.5 Shows the DM

Equation 3.3.4

Compute the total number of lifts performed for the 15 minute period.

(4 lifts) x (15 minutes) = 60

Divide the total number by 15 (60 ÷ 15 = 4)

Use the resulting value as the frequency to determine the frequency

multiplier

If we look at the table, the frequency multiplier for time duration of less

than 1 hour and a vertical height of 57.87 inches is 0.84.

Coupling Multiplier (CM)

The coupling is determined on how you handle the object when lifting, if it

is “good”, “fair” or “poor”. “Good” means containers that have handles or hand-

hold cut-outs of optimal design; “fair” means handles or hand-hold cut-outs of

less than the optimal design; “poor” means containers that are bulky, hard to

handle, or have sharp edges. The coupling type is modified by vertical location to

produce the coupling multiplier.

As we assessed, the plastic containers of the clothes are in optimal

design and the vertical distance is 53.94 inches and therefore the coupling type

is “poor”. The coupling multiplier is 0.90.

HM VM DM AM FM cm0.25 0.79 0.85 0.76 0.84 0.90

Fig. 3.3.6

Table 3.3.2 Table of values of Multipliers

RWL = 23 kg X HM X VM X DM X FM X AM X cm

RWL = 23 x 0.25 x 0.79 x 0.85 x 0.76 x 0.84 x 0.90

RWL = 2.22

C. CONCLUSION AND RECOMMENDATION

As we have computed, the load will pose risk to the worker. Carrying the packs of

clothes weighing from 4 to 11 kgs from the floor up to the shelves which height are about 60

inches is too risky and may cause the worker to reach too high just to put the clothes. As stated

in the principles of importance to ergonomics: “Joints must be in neutral position”, raised arms,

bent wrists, bent neck, and turned head are examples of poor postures where the joints are not

in a neutral position. Excessive reaches may cause the arms to outstretch and obviously

increase the stress in the muscles and joints. Also from the principles of importance to

ergonomics: “Limit the duration of any muscular effort”, continuous stress on certain muscles in

the body as a result of repetitive lifting movements leads to localized muscle fatigue, a state of

muscle discomfort and reduced muscle performance. The working effort or strength of the

worker will be reduced.

These are our recommendations:

Bring the clothes closer to the worker so as to decrease the horizontal distance.

Lower the height of the shelves or reduce the weight of the packs of clothes.

Move the origin and the shelves closer together to reduce trunk rotation or move

them further apart so that the worker will turn the feet and step rather than twist.

Reduce the lifting frequency rate of 4 lifts per minute to about 2 or 3 lifts per

minute. It will also reduce the muscle stress because of repetitive lifting.

INTRODUCTION

According to William Edwards Deming’s 85/15 rule, 85% of worker’s effectiveness is determined by the system he works within, and only 15% on his own skill. Indeed, the environment we work in greatly affects our performance. Take for instance in an office or in a classroom, one is required for thinking or in a condition that is flexible for communication or that is suitable in disseminating information that is needed for one’s work.

In a day-to-day basis, such conditions that concern temperature, lighting, noise, and etc. is important in the efficiency and productivity of a worker and comfort. Of course, every organization aims for a high productivity rate. And to cater this, workplace should be as productive to work with. Fortunately, Ergonomics has established standards for various factors that affect a person’s performance.

The group was assigned to measure the following Environmental Factors in the classrooms (#47-49) of Roque Ruano Building and University of Sto. Tomas. A few measurements from outside the building is also needed for this study.

1. Relative Humidity;2. Ambient Temperature;3. Wet Bulb Global Temperature;4. Air Ventilation;5. Sound Level; and6. Illumination

A. Relative Humidity

I. Standard Humidity: 30% - 70% RH

II. Actual Measurements (Rooms 47- 49)

Room RH1 RH2 RH3 RH4 RH C1. 47 51.5 50.5 48.4 50.2 48.12. 48 53 52.3 58.4 58.1 61.13. 49 52.5 58.6 65.1 66.7 69

III. Standards VS ActualThe measurements of relative humidity from the three rooms still fall in the standards.

IV. Conclusion and RecommendationsThe relative humidity gathered from the rooms is still under the standard which is from 30% to 70% RH. However, the values are somehow near the limit of 70% RH. This is due to the fact that the location of the rooms is in the 4 th floor of the building, which means, heat is more concentrated than of the other rooms, hence, air is dry. To aid this, the group suggests adding some or changing the present air-conditioning for ventilation.

B. Ambient Temperature

I. Standard Ambient Temperature:

Table 4.1.1 Actual Measurements of Relative Humidity

II. Actual Measurements (Rooms 47 - 49)

Classroom/Room AT1 AT2 AT3 AT4 ATC1. 47 24.3 25.4 25.1 25.4 25.62. 48 24.8 25.4 24.3 25.5 25.33. 49 25.0 25.1 26.1 26.4 26.5

III. Standards VS Actual

As seen above, the recorded Ambient Temperature of all the corners of the

rooms including the center fall under the type of work which is “Seated, thinking

task”. All the values exceed the upper limit of the type of work and the range of

the readings per room is small.

IV. Conclusion and Recommendations

The group concludes that the Ambient Temperature per room is too high.

In the rooms 47, 48 and 49, the types of work done is not only thinking tasks

while seated, these measurements are high.

Fig. 4.2.1 Table for Standard Ambient Temperature

Table 4.2.1 Ambient Temperature (°C)

Table 4.2.2 Summary of Ambient Temperature

Classroom/Room Minimum Maximum1. 47 24.3 25.62. 48 24.8 25.53. 49 25.0 26.5

For the classrooms 47 to 49, the group recommends that the aircon units must

be replaced with the one which are able to give cool air to the whole room, other

units are quite old and do not function as good. Another one is, because the

airconditioners are installed only on one the other side of the room, the other half

receives only a lesser cool air compared to the other half. If these units were

changed or fixed to a better function, performing tasks inside the rooms will be

done more comfortably. The air conditioners must also be low enough so that the

users of the room able to control the temperature as to what they want to set it,

provide also remote controls. When doing different tasks in different times of the

day, students or professors may feel uncomfortable with temperatures so

changing the temperature should be effortless for them.

C. Wet Bulb Global Temperature

I. Standard WBGT:

Category WBGT °F WBGT °C Flag color1 <=79.9 <=26.6 No flag2 80-84.9 26.7-29.3 Green3 85-87.9 29.4-31.0 Yellow4 88-89.9 31.1-32.1 Red5 =>90 =>32.2 Black

II. Actual Measurements (Room 47 - 49)

Classroom/Room WBGT 1 WBGT 2 WBGT 3 WBGT 4 WBGT C1. 47 19.0 19.5 19.8 19.9 19.82. 48 23.5 20 24.1 20.1 20.43. 49 24.8 23.4 23.5 23.6 24.5

III. Standards VS Actual

Table 4.3.1 Standard WBGT

Table 4.3.2 Actual Measurements of WBGT (°C)

Table 4.3.3 Summary of the measurements

Classroom/Room Minimum Maximum1. 47 19.0 19.9

IV. All readings fall under Category 1. This means No Flag sign.

V. Conclusion and Recommendations

The group concludes from the category, “No Flag Sign” that no serious effects will be done on the students’ health and professors’ as well. All these values are acceptable so we do not provide any recommendations.

D. Air Ventilation

I. Standard Air Ventilation:

V (m3/h)x20 m3/hr/person x (A (m2)/N (m2)) Area of the room in sq.m. Number of people usually present in the rooms Air Ventilation rate in A/C units

II. Actual Measurements (Rooms 47 - 49)

Room Area (sqm) No. of people No. of A/C

units

Air ventilation

(v)

Area A/C

Vent

47 11x10 51 2 6.82 m/s=

24552m/hr

0.04495

48 11x10 53 2 5.04m/s=

18144m/hr

3.795

49 11x10 55 2 3.58m/s=

128888

3.875

The standard ventilation for each room is computed as follows.

StandardV 1=20m3

hrperson

×86.25m2

86.25m2

51 persons

=1,020 m3

hr

Equation 4.4.1

Table 4.4.1 Actual Measurements of Air Ventilation

StandardV 2=20m3

hrperson

×110m2

110m2

53 persons

=1,060m3

hr

StandardV 3=20m3

hrperson

×80m2

80m2

55 persons

=1,100m3

hr

III. Standard VS Actual

ActualV 1=24,552m

hr×0.04495m2=1,103.61m

3

hr

ActualV 2=18,144m

hr×(0.03795m2×2)=1,377.12 m

3

hr

ActualV 3=12,888m

hr×(0.03875m2×2)=998.82 m

3

hr

NOTE: The areas of the A/C vents of rooms 47 to 49 were multiplied by 2

because there are two same A/C units in the room.

Classroom/

Room

No. of A/C

unitsStandard Actual

1. 47 2 1020 1103.612. 48 2 1060 1377.123. 49 2 1100 998.82

From the table 4.4.2 above, the comparison between standard and actual

measurement are more clearly seen. For the room 47, the actual measurement

exceeds the standard by more than 80 cubic meters per hour. On the other hand,

in room 48, well obviously, the actual is greater than standard. Lastly, on room

49, standard exceeded the actual measurement by more than 100 cubic meters

per hour.

IV. Conclusion and Recommendations

From the table 4.4.2 above, the comparison between standard and actual

measurement are more clearly seen. For the room 47, the actual measurement

Table 4.4.2 Summary of measurements (m3/hr)

exceeds the standard by more than 80 cubic meters per hour. On the other hand,

in room 48, well obviously, the actual is greater than standard. Lastly, on room

49, standard exceeded the actual measurement by more than 100 cubic meters

per hour.

Based on the results, room 48 has the most favourable air ventilation rate

and the group recommends none. But, in the remaining rooms 47 and 49, the

ventilation must be improved. Volume of fresh air must be compatible with how

the tasks in each room require

E. Sound Level

I. Standard Sound level: D (noise dose) should not exceed 100%

II. Actual Measurements (Rooms 47 – 49)

a. Engineering Pavilion (Sound Level: 78.2 decibels)

b. Botanical Garden (Sound Level: 73.1 decibels)Fig. 4.5.1 Engineering Pavilion

c. UST Chapel (Sound Level: 57.9 decibels)

d. Plaza Calderon (Sound Level: 69.0 decibels)

Fig. 4.5.2 Botanical Garden

Fig. 4.5.3 UST Chapel

e. Grandstand (Sound Level: 65.3 decibels)

f. Plaza Mayor (Sound Level: 70.1 decibels)

Fig. 4.5.4 Plaza Calderon

Fig.4.5.5 UST Grandstand

g. Miguel de Benavidez statue (Sound Level: 72.5 decibels

h. Quadricentennial Square (Sound Level: 64.5 decibels)\

Fig. 4.5.6 Plaza Mayor

Fig. 4.5.7 Miguel de Benavidez Statue

LocationNo. of hours of exposure

Sound level measured

1. Engineering Pavilion  1  78.22. Lover’s Lane  1  72.53. Plaza Mayor  1  70.14. Grandstand  1  65.35. Santissimo Rosario Church  1  57.96. Plaza Calderon  1  69.07. Botanical Garden  1  73.18. Quadricentennial Square  1  64.5

To solve for the Noise Dose (D), the following formula is used.

D=100 ( 1T 1+ 1T 2+ 1T3 + 1T 4 + 1T5 + 1T 6+ 1T 7+ 1T 8 ) Where,

D = Noise Dose

Ti = Time (where i = 1,2, …, 8)

In solving for Ti for every location, the following formula is used.

Fig. 4.5.8 Quadricentennial Square

Table 4.5.1 Summary of Measurements (in decibels)

Equation 4.5.1

T i=8

2(L−905 )

Li = Sound Level reading per location (where i = 1,2, …, 8)

Solving for Ti to T8, we have,

T 1=8

2( 78.2−905 )

=41.07hours

T 2=8

2( 72.5−905 )

=90.51hours

T 3=8

2( 70.1−905 )

=126.24hours

T 4=8

2(65.3−905 )

=245.57hours

T 5=8

2( 57.9−905 )

=685.02hours

T 6=8

2( 69.0−905 )

=147.03hours

T 7=8

2( 73.1−905 )

=83.29hours

T 8=8

2( 64.5−905 )

=274.37hours

Then, the T values are substituted to D’s equation.

D=100 ( 141.07

+ 190.51

+ 1126.24

+ 1245.57

+ 1685.02

+ 1147.03

+ 183.29

+ 1274.37 )

D=100 (0.0713 )

Equation 4.5.2

D=7.13%

D≤100%

7.13%≤100%

III. Standard vs. Actual Measurements

The T values shown are the maximum (length) that a person can stay in every

area. Those values that are large says that there is no harm for people to stay there for

some long period of time. The range of the readings gathered is from 30 decibels to 80

decibels which are within the noise level limitations. In the sound level, the resulting

values were less than 100% compared to Noise Dose. The noise levels were only at

7.13% harmful to the people that will stay in the area.

IV. Conclusion and Recommendations

Since the Noise Dose results 7.13%, this only means that the Sound Levels in

those locations are not harmful to people. The range of 30 decibels to 80 decibels were only to

imply that there is no risk in obtaining any hearing destruction and displeasure. And since it is

also less than 100%, the noise dose, we provide no recommendations.

F. Illumination

I. Standard

Type of Activity CategoryRanges of Illuminances Reference

Work-PlaneLux FootcandlesPublic spaces with dark surroundings

A 20-30-5 2-3-5General lighting throughout spacesSimple orientation for

short temporary visitsB 50-75-100 5-7.5-10

Working spaces where visual tasks are only occasionally performed

C 100-150-200 10-15-20

Table 4.6.1 Table for standard illuminances for nine types of activities

Performance of visual tasks of high contrast or large size

D 200-300-500 20-30-50

Performance of medium tasks of low contrast or very small size

E 500-750-1000 50-75-100Illuminance on taskPerformance of visual

tasks of low contrast or very small size

F 1000-1500-2000 100-150-200

Performance of visual tasks of low contrast and very small size over a prolonged period

G 2000-3000-5000 200-300-500Illuminance on task, obtained y a combination of general and local (supplementary lighting)

Performance of any prolonged exacting visual task

H 5000-7500-10000 500-750-1000

Performance of very special visual tasks of extremely low contrast and small size

I10000-15000-

200001000-1500-2000

For the rooms, the age factor point is -1 because at most, users of the said rooms were

below 40 years old. The reflectance factor is set to -1 because rooms are painted light which

gives a reflectance of 75%. This is higher than 70% reflectance value which weight is -1. The

Speed and accuracy factor is set to 0 (zero) because in tests it is important. Summing these up,

the resulting value is -2, so we conclude that it is the lowest value among the three.

II. Actual Measurements

Classroom/Room Lux 1 Lux 2 Lux 3 Lux 4 Lux C1. 47 209 164 148 208 1602. 48 147 157 168 156 2243. 49 111 198 168 83 193

III. Standard vs. Actual Measurements

Table 4.6.2 Actual Measurements of illumination (lux)

Table 4.6.3 Summary of measurements

Classroom/Room Minimum Maximum1. EE Lab 2 160 2082. 41 147 2243. 57 111 198

For room 47, 2 locations reached the recommended illumination level. These are quite

greater than the recommended, 209 and 208. These are good.

For room 48, the four sides of the room has low lux levels, ranging from 147 to 168. The

center of the room has the highest lux reading, 224 lux. This is maybe due that the light from the

sources are not outwide spread.

For room 49, out of the readings in the said room, 3 values are lower than the

recommended level of illumination. Only the reading from one side and in the center is close.

Again, this is maybe due that the sources of light are not spread out widely.

IV. Conclusion and Recommendation

The group concludes that in each room, there are some fluctuations in the readings.

That is, the difference in their illumination readings is high. Some light sources might be

concentrated in only one side of that room so other corners receive lesser light.

Also, we recommend that the light position in the room must be changed to better lighten

up other sides of the room. This will result in improve lighting in the rooms and will increase the

performance of the users of the rooms.