Light analysis

1. Light Analysis
Daylight Factor
According to MS1525, Daylight Factor distribution is as shown below:
Daylight Factor, DF= Ratio of interior illuminance (𝐸𝑖) inside the structure to
available outdoor illuminance (𝐸𝑜) outside the structure
Formula for Daylight Factor (DF):
𝐷𝑎𝑦𝑙𝑖𝑔ℎ𝑡 𝐹𝑎𝑐𝑡𝑜𝑟 =
Ei (internal illuminance at a given point)
Eo (outdoor illuminance)
× 100%
Daylight Factor (DF)
DF, %
>6 Very bright with thermal & glare problem
3~6 Bright
1~3 Average
0~1 Dark
Natural Illumination Calculation
Illuminance Example
120,000 lux Brightest sunlight
110,000 lux Bright sunlight
20,000 lux Shade illuminated by entire clear blue sky, midday
1000~2000 lux Typical overcast day, midday
<200 lux Extreme of darkest storm clouds, midday
400 lux Sunrise or sunset on clear day (ambient illumination)
40 lux Fully overcast, sunset/sunrise
<1 lux Extreme of darkest storm clouds, sunrise/sunset

2. Fixture Properties
Type of Fixture 40W led commercial office led pendant
light
Company Passun
Dimension 0.12 x 1.2 (W x L)
Lumen (lm) 4000
Wattage (W) 40
Colour Designation (K) Warm White, 2700 – 3000K
Colour Rendering Index (CRI) 80
Lumen Method Calculation
Location Admin office
Dimension
Floor Area (A)
Types of Lighting Fixture LED
Lumen of Lighting Fixture (Lux) 4000 lm
Height of Luminaire (m) 3.0
Height of Work Level (m) 0.8
Mounting height (Hm)
Reflection Factors
Room Index / RI (K)

3. Utilisation Factor (UF)
Maintenance Factor (MF)
Standard Illuminance by MS1525
Number of light required
𝑁 =
𝐸𝑋𝐴
𝐹 × 𝑈𝐹 × 𝑀𝐹
Spacing to Height Ratio (SHR)
Fitting Layout by Approximately (m)
Artificial Lighting Analysis
Lumen Method
Lumen method is used to calculate the light level in a room. It is a series of
calculation that uses horizontal luminance criteria to establish a uniform
luminaire layout in a space. It can be calculated by dividing the total number of
lumens available in a space by the area of the space.
The calculation is below:

4. 𝑬 =
𝒏 × 𝑵 × 𝑭 × 𝑼𝑭 × 𝑳𝑳𝑭
𝑨
Where,
E = Average illuminance to cover the space
n = Number of lamps of each luminaire
N = Number of luminance
F = Lighting design lumens per lamp, i.e. Initial bare lamp luminous
UF = Utilization factor for the horizontal working plane
LLF = Light loss factor
A = Area of the horizontal working plane
Lumen method can also be calculated and used to determine the number of
lights should be installed on the site. To know the number of lamps, calculation
of total luminance of the space need to be done based on the number of fixtures
and examines the sufficiency of light fixtures on that particular space.
𝑵 =
𝑬 × 𝑨
𝑭 × 𝑼𝑭 × 𝑴𝑭
N = Number of lamps

5. E = IL luminance level required (Lux)
A = Area at working plane height (m x m)
F = Average luminous flux from each lamp (lm)
UF = Utilization factor, an allowance for light distribution of the luminaire
and the room surfaces
MF = Maintenance factor, an allowance for reduced light output because of
deterioration and dirt
Room Index
Room Index, RI, is the ratio of room plan area to half wall area between the
working and luminaire planes, which can be calculated by:
𝑹𝑰 =
𝑳 × 𝑾
𝑯 𝒎 × (𝑳 + 𝑾)
Where,
L = Length of room

6. W = Width of room
𝐻 𝑚 = Mounting height, the vertical distance between the working plane and
the luminaire.
Light Loss Factor
Light loss factor is need to be considered when calculate Lumen Method. It is
allowing forecasting the performance of the system over a given lifetime to meet
the minimum light standards it helps minimize the reliability of system has been
planned and designed for future operation.
The calculation for light loss factor is as below:
𝐿𝐿𝐹 = 𝐿𝐿𝐷 × 𝐿𝐷𝐷 × 𝐴𝑇𝐹 × 𝐻𝐸 × 𝑉𝐸 × 𝐵𝐹 × 𝐶𝐷
Where,
LLD = Lamp lumen depreciation
LDD = Luminaire dirt depreciation
ATF = Ambient temperature effects
HE = Heat extraction
VE = Voltage effects
BF = Driver and lamps factors
CD = Component depreciation

7. Fixture Properties
Type of fixture Coreline slim downlight
Image of fixture
Product dimension (mm) 215 (diameter)
Type of luminous Warm white
Luminous flux (lm) 2000
Power (W) 28
Color temperature (K) 3000
Color rendering index 80
Average life rate (hours) 50000

13. Kids Corner

14. The selected area of the kids corner is located at the back of the buildings 1st floor
facing toward east south, hence this area do not have direct sunlight due to lower
position of the sun. The purpose of the area is provide kids book and spaces such as
playful furniture to make it an interesting zone and books suitable to kids. Beside
that, the neighbor high rise has blocked most of the sunlight. Hence most of the time
the area is shaded, thus there is less heat gain on this space for children. Other than
that, the most of the natural light from this space is from the back, due to back
facade is an open while plantings act as buffer exterior heat and unsightly back
street. At the same time, the planting also provide for foreground against the greens
on the opposite. The space have provided for optimal reading conditions for the
users.

15. Admin Office

16. Admin office is selected, that place function as a working place for the staff. Most
of the paper work or even staff discussion is held at that area. This area does not
have any expose area towards sun. Hence, most of the time is shady if without
any artificial lighting. Furthermore, to have a standard lighting and achieve such
a requirement that having last long lighting I have chosen 40W led commercial
office led pendant light as the main artificial light source for that area. Therefore,
it can provide enough of light for that area and last long for area that require
turn of the artificial light most of the time.

17. According to calculation 15 fixture arranged in 5 row and each row with 3 fixture
of Coroline slim down-light are required. Based on the area requirement, kids
corner does not need strong lighting due to the area having few faces that expose
to the natural light. Therefore, that area does not need artificial lighting all time
and to prevent strong lighting to kids. Based on requirement, the retina of kids
cannot afford strong lighting if not it will cause short sightedness.

18. According to calculation 12 fixtures arranged in 4 row and each row with 3 fixtures
of 40W leg commercial office led pendant lights are required to achieve the
recommended MS1525 illumination level of 300- 500 lux. This should provide for
sufficient artificial conditionsfor theuseofadmin office.