Positioning the Light Fittings

After the number of required light fittings are calculated, the position of the light fittings shall be evenly spaced out to achieve a more even light distribution. The number of rows and columns of the light fittings can be calculated as below:

Number of light fittings along = sqrt(N x L / W)

Number of light fittings across = sqrt(N x W / L)

where N = total number of light fittings required; L = total length of room; W = total width of room

Example

Consider an air conditioned office room with the dimension of 12m (length) by 6m (width) by 3.2m (height). Assuming that the work desk is at 0.75m. The required lux level is 300 lux and the type of light fitting is 2x36W bare batten which gives out 6000lm lumen output.

From the previous post, the number of light fittings required is calculated to be 12. The next step is to calculate the number of rows and columns of the light fittings.

Number of light fittings along = sqrt(N x L / W) = sqrt(12 x 12 / 6) = 4.89

Number of light fittings across = sqrt(N x W / L) = sqrt(12 x 6 / 12) = 2.45

In order to evenly space out the light fittings, we can take 4 number of light fittings along the length and 3 number of light fittings along the width. To space out the light fittings evenly, the distance between light fittings are calculated below:

x-spacing = 12 meter / 4 = 3 meter

y-spacing = 6 meter / 3 = 2 meter

And the result is shown below:

The above steps are the manual calculation for positioning the light fittings but care must be taken to consider the aesthetic issues, the furniture layout (whether the light will be blocked by cupboard etc) and so on.

Number of Light Fittings Required (Indoor Area)

Once the type of light fittings is determined, one can proceed to calculate the number of light fittings required to illuminate the area to a certain lux level. DIALux is a great tool to perform the light simulation for both indoor and outdoor and it can be downloaded here. Without the software, one can use the manual calculation step as below to perform the calculation with considerable accuracy (credits to Fuzion Lighting).

Step 1:  Understand the utilisation factor table that is available on most fittings

UTILISATION FACTOR TABLE (for 2×36 bare batten)
LOR: 88.1%			SHR NOM 1.75: 1.0					Disregard SHR MAX.
Reflectance			Room Index (K)
Ceiling	Wall	Floor	0.75	1.00	1.25	1.50	2.00	2.50	3.00	4.00	5.00
0.50	0.30	0.20	0.30	0.37	0.42	0.46	0.52	0.56	0.59	0.63	0.66

LOR  – Light output ratio for this fitting. Not required in a simple calculation.

SHR NOM – Nominal Spacing to Height ratio. For a given mounting height we can see the nominal spacing between fittings. Eg. 1.75 to 1 means that for every 1 metre of mounting height (above work plane) we should have a maximum 1.75 metres between fittings.

SHR MAX – Used by lighting design software and not needed for manual calculations.

Reflectance – Select a horizontal line for the reflectance values that best describe the room.

Type of Area	Ceiling	Walls	Floor
Air Conditioned Office	0.7	0.5	0.2
Industrial	0.5	0.3	0.2

Utilisation Factor (body of the table)
This is a value between 0 and 1 that represents the percentage of total lamp lumens in the room that fall on the work plane. It takes into account the room reflectances, room shape, polar distribution and light output ratio of the fitting.

Step 2: Calculate Room Index (K)

Room Index: The room index is a number that describes the ratios of the rooms length, width and height.

Formula: K = (L x W) / [ Hm (L + W) ]

where L = Room Length; W = Room Width; Hm = Mounting Height of Fitting (from working plane); Work Plane = Desk or Bench Height

The room index (K) usually lies in between 0.75 to 5.0.

Note: This formula for K is only valid when room length is less than 4 times the width or when the K value is greater than 0.75.

Step 3: Using the room index and reflectance values in the utilisation factor table

• For the horizontal row select the reflectance that best describes the room.
• For the vertical column select the room index value K as calculated above.
• The utilisation factor for this fitting in this room is where the row and column intersect.

Step 4: To calculate the number of fittings required use the following formula

Formula: N = (E x A) / (F x uF x LLF)

where N = Number of Fittings; E = Lux Level Required on Working Plane; A = Area of Room (L x W); F = Total Flux (Lumens) from all the Lamps in one Fitting; UF = Utilisation Factor from the Table for the Fitting to be Used; LLF = Light Loss Factor. This takes account of the depreciation over time of lamp output and dirt accumulation on the fitting and walls of the building.

The typical LLF values are as follow:

Air Conditioned Office	0.8
Clean Industrial	0.7
Dirty Industrial	0.6

Example

Consider an air conditioned office room with the dimension of 12m (length) by 6m (width) by 3.2m (height). Assuming that the work desk is at 0.75m. The required lux level is 300 lux and the type of light fitting is 2x36W bare batten which gives out 6000lm lumen output.

First, the room index needs to be calculated first:
K = (L x W) / [ Hm (L + W) ]
= (12 x 6) / [(3.2 – 0.75)(12 + 6)]
=1.63

Referring to the utilisation factor table,
uF = 0.52 (FOR k=1.63) X 0.7 (REFLECTANCE VALUE FOR CEILING) = 0.364

LLF for an air-conditioned office is 0.8.

To calculate the number of light fittings required,
N = (E x A) / (F x uF x LLF)
= (300 x 72) / (6000 x 0.364 x 0.8)
= 12.36

Therefore, a total of 12 nos 2x36W bare batten fitting is required.

Lighting Terminology

Before we determine how many light fixtures we require to light up a certain area, we should first understand several basic lighting terminologies in order to come out with a more precise and cost-efficient solution.

Alternating Current (AC): the flow of electric charge in a circuit that reverses its direction periodically. In Malaysia, the standard frequency of AC is 50Hz and this is generally the method for delivering electricity to household and buildings.

Ballast: A device used with lamp to supply sufficient voltage to operate the lamp but limit the amount of current in the circuit which would otherwise rise to destructive levels due to the lamp’s negative resistance characteristic

Color Rendering Index (CRI): a measure of a lamp’s ability to show object colors accurately and naturally, with the scale ranging from 1 (low pressure sodium) to 100 (sunlight). Lower CRI represents that the color may appear unnatural. In general, incandescent lamps have a CRI above 95 while fluorescent lamps have a CRI of approximately 50-70.

Color Temperature: a method of describing the color characteristic of a light source whether it is warm (yellowish) or cool (blueish) and it is often measured in Kelvin (K). Light sources below 3200K are considered “warm” and is often used in home, restaurants etc to create friendly and inviting atmosphere whereas light sources above 4000K are considered “cool” and is suitable for offices or classrooms areas.

Direct Current (DC): the unidirectional flow of electric charge in a circuit

Driver, LED: a device that provides power supply to the LED and regulates the current flow into the lamp to maintain a steady lumen output.

Efficacy: a measure of efficiency to determine the ratio of light output to energy consumed, measured in lumens per watt (lm/W). It varies with the type of lamp (refer here)

Illuminance: a measure of total luminous flux per unit surface area, measuring how much the incident light illuminates the surface, measured in lux.

Light Loss Factor (LLF): a factor used to estimate the reduction in lumen output of a light source over time due to a string of factors such as dirt and dust accumulation, voltage fluctuations and lamp depreciation etc.

Lumen (lm): an international SI unit to measure the amount of light that is being produced or emitted from a light source.

Luminaire Efficiency: the ratio of lumen output by a light fixture to the lumen output by the lamp installed in the fixture. A luminaire with more than 0.8 efficiency is considered efficient whereby 0.6 efficiency is considered standard.

Luminous Flux: the overall light output from a light source, measured in lumens

Lux (lx): the SI unit to measure illuminance per unit area

Types of CCTV Camera

In order to achieve a cost-efficient solution to monitor the building, one should know the types of CCTV camera to be used and the coverage area to be monitored. CCTV cameras come in different types, designs and configurations. Therefore, a house owner / business owner / management officer for complexes have a wide range of CCTV cameras to select from depending on their usage and application. Below are the more commonly used CCTV cameras:

• Bullet Camera

Bullet cameras have long and cylindrical shape, usually designed for indoor use, but they can be used outdoor as well. The camera usually does not have pan, tilt or zoom feature and it is used to capture the video image at a fixed direction. However, it has a mounting bracket that allows one to change the viewing direction.

• Box Camera

Box cameras are suitable for outdoor use and for longer distance usage. Generally, it has a narrower but further viewing angle as compared to dome camera and the likes. These cameras can come with fixed lens or varifocal lens and they usually provide users the flexibility to zoom. Besides that, it can be housed in an outdoor housing which is impenetrable to moisture, insects, dust and other elements.

• Dome Camera

It derives its name from its dome-shaped design. Hence, it is often used in indoor area such as retail area because of its unobtrusive housing design. Some of the dome cameras come with vandal-resistant or water-resistant body. It has a glass window and it is not easy to identify which direction the camera is shooting at. With this, house owners or business owners do not need to purchase multiple camera to shoot at different direction as other people will not know the direction of the camera.

• PTZ Camera

PTZ stands for Pan, Tilt, Zoom, giving the users to control the camera from a remote location using controller to pan, tilt and zoom the camera. It is more costly compared to other types of camera, but it is still a better solution in a wide area as it can replace multiple cameras to monitor a large area and far perimeter. It usually has a 360 degrees viewing field and powerful zoom lens that allow users to view high details at a far distance. Comparing to other cameras, it requires more maintenance as it involves a lot of mechanisms such as motors, belts, heaters etc and require a security officer to operate the camera, otherwise it will be left pointed at a static position.

Introduction About Closed Circuit Television (CCTV) System

Closed Circuit Television (CCTV) System is a system that utilize surveillance camera to transmit video signal to a specific places on a set of monitors. It is mainly meant for security purposes where the building requires some sort of surveillance or monitoring. Once an area is determined to have surveillance camera,you would have to decide what kind of system it should be.

Before determining what kind of cameras to be used, you have to decide what kind of surveillance system. Generally, in Malaysia, the two commonly used surveillance system are:

• DVR-Based Analog CCTV System

The video image is captured using the analog cameras and the video signal is then digitized and compressed for storing and viewing on a set of monitors. To achieve this, a digital video recorder (DVR) is required to convert the video signal into digital format. In early days, the hard disk space was limited thus many CCTV manufacturers developed their own proprietary video compression algorithms. However, thanks to the advancement of technology now, standard compression algorithms such as MPEG-4 become more common and widely accepted, thus most of the video signal is now compressed to these video format. The system generally uses coaxial cable (RG6, RG11 and similar) to link up the analog cameras to the DVR.

• Network-Based CCTV System

As suggested by the name, the system utilizes network camera, also known as IP camera and the video signal is transmitted over the IP network via network switches and then recorded on a PC server complete with the video management software as well as the network video recorder. This is a fully digitised system where there is no analog components involved. The system generally uses data cable (CAT5E, CAT6 and similar) to transmit the signal from the camera to the workstation. Some network cameras can be powered up using the same data cable and this is known as Power over Ethernet (PoE).

Comparison between DVR-Based Analog CCTV System and Network-Based CCTV System

DVR-Based Analog CCTV System has the following advantages:

• Consistent recording quality
• Bigger coverage from the main equipment ie. DVR, approximately 250m using RG6 cable
• Cheaper equipment (cameras and DVR)

Whereas the Network-Based CCTV System has the following advantages:

• Ability to use high- resolution (megapixel) cameras
• Ability to use Power over Ethernet and wireless functionality
• Full access to functionalities such as pan, tilt, and zoom; audio and digital inputs and outputs over IP, together with video
• Camera settings and system adjustments over IP
• Full flexibility and scalability
• Easy integration with other security system such as card access system or vehicle barrier gate system

Weighing the advantages of both system, no doubt, the network-based CCTV system has a higher set up cost due to the more pricey equipment but over time, it provides a more cost-efficient solution and it can support up to thousands of cameras and provide a higher-resolution video image quality. In comparison, the DVD-based analog CCTV system requires the conversion from analog signal to digital signal and this conversion results in the degradation of the video signal quality.

List of Light Fittings Suppliers/ Manufacturers/ Distributors in Malaysia

The below is a list of light fitting suppliers/ manufacturers/ distributors in Malaysia:
(Click on their logo to view their products)

1. Philips Lighting Malaysia

Address:
Level 9, Menara Axis,
No.2, Jalan 51A/223,
46100 Petaling Jaya,
Selangor Malaysia
Tel: +603-7965 7488

2. Osram Malaysia

Address:
Unit 20-2, Level 20, CP Tower
No.11, Jln. 16/11,
Pusat Dagang Seksyen 16
46350 Petaling Jaya, Malaysia
Tel: +603-7959 0000

3. Sirijaya

Address:
No. 9, Lebuh Perusahaan Klebang 9,
IGB International Industrial Park,
31200 Ipoh Perak,
Malaysia.
Tel: +605-292 3888

4. Fagerhult

5. YLI Industry

Address:
Pt 14503 & 14504, Persiaran Batu Gajah Perdana 6,
Taman Batu Gajah Perdana,
Pusing, Perak 31550,
Perak, Malaysia
Tel: +605-366 5227

6. Kohsun

Address:
No. 11, Jalan BK1/11,
Kinrara Industrial Park,
Bandar Kinrara, 47180 Puchong,
Selangor Darul Ehsan, Malaysia.
Tel: +603-8075 1662

7. Oversea Lighting & Electric

Address:
Lot 6595, Jalan KPB12,
Kawasan Industri Kampung Baru Balakong,
43300 Seri Kembangan,
Selangor Darul Ehsan, Malaysia
Tel: +603 8964 1888 | 8964 1878 | 8964 1899

8. Starlite Projects & Manufacturing

Address:
Lot 1837, Kampung Baru Balakong,
43300,Sri Kembangan,
Selangor Darul Ehsan, Malaysia.
Tel: +603-8961 7912

9. PCO Lite

Address:
Lot No. 157880 (PT 1283), Off Jalan Degong,
31900 Kampar, Perak Darul Ridzuan,
Malaysia.
Tel: +605 – 466 5313 / 465 1020

10. R.G.E Lighting

Address:
Lot 265 Tingkat Perusahaan 5,
Kawasan Perusahaan Perai 2,
Penang, Malaysia.
Tel: +604-399 7397

11. Davis Lighting

Address:
65 Jalan PJS 11/7, Bandar Sunway
46150 Petaling Jaya
Selangor, Malaysia
Tel: +603-5636 4348

12. Pierlite

Address:
No. 36 & 38, Jalan SS 4C/5
47301 Petaling Jaya
Selangor, Malaysia.
Tel: +603-7803 9777

If there is other light fittings supplier, kindly comment below. Cheers! 🙂

Type of Lamp

A lamp is a replaceable electric device that emits visible light by the flow of electric current. Light bulb has already came into existence in the 19th century when Thomas Edison invented the first practical incandescent lamp. And now there are many types of lamps and the efficiency of the lamp has been improving day by day.

Generally, lamp can be categorized into two main groups:

• Incandescent lamp – produces white light when electric current is passed through the wire filament until it is heated up to a certain temperature that it starts to glow

• Gas-discharge lamp – generates visible light by creating an electrical discharge through ionized gas.

In comparison, gas discharge lamp has a higher efficiency but it requires an external electronic component such as ballast to limit the current flow through the gas, thus resulting in a more complex manufacturing process. Besides that, some of the gas discharge lamp have a long start-up time to reach their maximum light output. However, they are still commonly used lamp nowadays due to its higher efficiency.

The lamp can be further broken down into the following groups :

Name	Type	Efficiency (lm/W)	Lifetime (MTFB) (hrs)	Color Temperature (lm/W)	Color
Incandescent	Continuous	4-17	2-20000	2400-3400	Warm white
Halogen lamp	Continuous	16-23	3000-6000	3200	Warm white
Fluorescent lamp	Mercury line + Phosphor	52-100	8000-20000	2700-5000	Various color
Metal halide lamp	Quasi-continuous	52-100	6000-20000	3000-4500	Cold white
Sulfur lamp	Continuous	80-110	15000-20000	6000	Pale green
High pressure sodium	Broadband	55-140	10000-40000	1800-2200	Pinkish orange
Low pressure sodium	Narrow line	100-200	18000-20000	1800	Yellow
Light-emitting diode	Line plus phosphor	10-110	50,000-100,000	2700-6000	Various color

Incandescent lamp is usually used for domestic use or decorative lighting whereas fluorescent lamp is widely used in household, shops and offices. High pressure sodium and low pressure sodium are used more frequently for outdoor lightings while metal hallide lamp is usually used for areas with high ceiling. LED lamp recently gets more and more popular as its cost per watt is reducing and is more environment friendly. In comparison, low pressure sodium lamp has the highest efficiency and hence it is more economical to use.

When designing the lighting for an area, the above factors should be taken into consideration, such as the efficiency, color temperature, lifetime, cost per watt etc. Once the type of light fitting and lamp is decided, one can proceed to arrange the lighting in the most appropriate manner to achieve the desired lux level.

Type of Indoor Light Fittings

A light fitting is an electrical device that produces light with the use of lamp and it often includes the light fitting body and a lamp holder to hold the lamp in place. Light fitting may also have a switch to control the light, whether it is controlled by a manual switch, timer or motion detector. To light up the lamp, it requires electrical connection to a power supply.

When it comes to lighting design, determining the suitable type of light fitting is one of the first few steps and this heavily relies on the usage of the room as well as the room structure. There is a wide range of light fittings in the market such as:

• Batten type  (Suitable for staircase, public hallway, corridors, carpark etc)

Most batten-type light fitting comes with fluorescent lamps and is designed as surface-mounted or suspended type. They are commonly used in commercial, industrial as well as residential environments. They have different accessories to meet different design requirements. For example, they may have wireguard that is vandal proof and it is suitable for loading bay or car park area. They also may have plastic covers (diffuser) around the lamp to give a softer ambient light. Some of the diffuser are polycarbonate type and is IP65 rated, thus is both waterproof and dustproof. Besides that, they may have reflector that can help to focus the light wave to targeted area.

• Troffers (Suitable for offices, classroom etc)

Recessed fluorescent light fittings which can usually fit in 1 to 4 fluorescent tubes, usually installed in suspended tiled ceiling. Typically has the dimension of 300mm x 1200mm, 600mm x 1200mm and 600mm x 600mm (kindly note that the light fittings measured in imperial units and metric units are different). Like batten type, they also may come with different accessories such as prismatic diffuser or louvre.

• Downlights (Suitable for public hallways, corridors, washroom, meeting rooms, reception etc)

Can be recessed into the ceiling or surface-mounted and generally comes in round or square. May have different type of diffuser to give different type of light effect. Some may be adjustable where their body can be rotated to direct the light towards a targeted area. Generally speaking, the larger the opening, the more efficient the downlight is.

• Suspended type

Light fitting that generally comes with hanging rod and is suspended down to a certain length to distribute the light at certain areas. In some areas with high ceiling, this is one of the light fittings that can be used. For example, in meeting rooms, some may use this right above the meeting tables.

• High bay or low bay (Suitable for warehouse, assembly areas, sport complexes etc)

A pendant type light fitting that normally uses high intensity discharge (HID) lamp that is more intense that other type of lamps. Low bay light fittings are usually used for areas where mounting height is less than 6 meter whereas high bay light fittings are usually installed for areas where mounting height is higher than 6 meter. Generally, low bay light fittings have a bigger openings (approximately 22″ to 28″ in diameter) in comparison to high bay light fittings with opening of about 15″ to 18″ in diameter. Low bay light fittings are designed in such a way in order to distribute the light more evenly whereas the high bay light fittings can concentrate the light beam at a targeted area. Some may come with fluorescent lamp as it gives better uniformity but lower lumen output compared to HID lamp

The light fittings mentioned above are the more commonly used light fittings. Apart from the type of light fittings, it is also important to consider the light fittings and lamp combination because not all the light flux emitted from the lamp will be directed to the working plane as a result of reflection and absorption. This is usually reflected as the light output ratio and often found in the datasheet or catalogue of the light fittings.

In summary, understanding both type of light fittings and type of lamp will definitely help you make a better decision in doing lighting design.

Lux Level

When it comes to designing the lighting for a building, be it commercial or residential building, the very first step is understand the usage of the room and then to understand the building structure of every single room to ease your selection of the light fitting which will be covered in next post.

We have to bear in mind that offices or any other working areas such as classroom should have natural lighting if possible. Adequate light fittings shall be provided so that work can be easily seen and there is a guideline on how bright a room should be lit up.

But before we go into that, let us look at one of the most important criteria that we often look at when we design the lighting system.

Illumination / Lux level – The total luminous flux which falls on a surface and it shows the intensity of the incident light. The value is affected by the wavelength of the emitted light and the distance between the light source and the illuminated area (credits to LedRise). The further the target surface from the light source, the lower the illumination level. This is measured in the unit of lux.

The outdoor lux level is approximately 10,000 lux on a clear day. For an area that is close to windows, the lux level may be at about 1,000 lux. And at those areas where there is little exposure to natural lighting, it can be as low as 50 lux. Hence, light fittings should be added to compensate the low lux level.

Below are the general lux level standard that can serve as a guideline:

Room Illumination Level

Location	IES Standards	MS 1525 Recommendation	Panduan Teknik JKR
Corridors, Passageway	100	50	100
Staircase	150	100	100
Entrance halls, lobbies, waiting rooms	150	100	100
Kitchen	500	150-300	300
Food Stores	150	150-300	300
Dining Room, Cafeteria	300	200	300
Changing locker and cleaner’s room, cloak rooms lavatories	150	100	100
Rest rooms	150	150	150
General office with mainly clerical task	500	300-400	500
Executive office	500	300-400	300
Conventional shop with counters	500	200-750	500
Multipurpose hall	500		300

The above table serves as a guideline and it may vary as per your design. But in general, places where it involves working on paper or computer requires 500 lux, car park driveway requires 150 lux, parking bay requires 75 lux, M&E room requires 200 lux, lobby area or reception area requires approximately 250 to 350 lux. This targeted lux level will generally give you a guideline on how many light fittings you require in a room as well as how you should arrange the light fittings.

After knowing what is the targeted lux level to achieve for every single room, you have to what is the nature of the room. For example,

• Kitchen – hygiene type light fitting which is waterproof and dustproof is required as there is cleaning and washing being carried out.
• Cold room – special light fitting that can sustain the cold temperature is required
• LPG storage – anti explosive type light fitting is required as normal light fitting may cause spark and then explosion
• Outdoor areas – weatherproof light fitting is required especially for a tropical country like Malaysia

Besides that, it is important to know the ceiling or the slab, after all it is where you will be installing the light fitting at. Below are some of the more common ceiling types. By knowing what are the type of ceiling, this will ease you to select the suitable light fitting type of that particular area.

1. Ceiling grid (2′ by 4′, 2′ by 2′, 1200mm by 600mm and 600mm by 600mm). Bear in mind that the size in imperial format is different from that of metric format.

2. Plaster ceiling board

3. Skim coating (no ceiling)

After knowing these few general information, then you will have to select the suitable light fittings as well as lamp that suit your design requirements. This will be covered in the next topic.

Cheers 🙂

Knowing the Building Inside Out

Before starting the design of a system or service for a building, it’s highly advisable to study and understand the building structure in and out. First, you need to know what type of building is it and for what usage, whether it’s a residential buildings or commercial buildings. To deliver a high-quality design and to reduce the possibility of a wrong design which cause a costly mistake, you have to visualize and imagine that you yourself are in the building itself and know what are the building structures around you.

Get to know the 6 buildings structures around you:

• Front, Rear, Left, Right – Check if there is wall (whether it’s half-height or full-height) / window (whether it’s from floor level or not) / column (round or rectangular) etc
• Top – Check if there is ceiling (what type of ceiling? Plaster ceiling board or ceiling grid?) or just bare concrete
• Bottom – Check if there is concrete slab or if it’s soil area (outdoor)

Other than this, it’s also best to know what are the adjacent rooms used for as they might affect your design. For instance, the cable containment shall not cross the staircase area as it might cause obstruction during emergency time. It is also advisable not to locate them in a easily noticeable area especially public area as it will be an eye sore to look at. It is very important to know the 6 building structures so that you will know if you can install your system/ service onto them.

Apart from this, it’s also very important to know what is the room used for. Below are some of the common rooms in a buildings:

• Bedrooms
• Washrooms / Toilets/ Public Amenities/ Disabled Toilet/ Shower Room
• Lobby (Please note that they are sometimes double or even triple volume)
• Corridoor
• Exhibition Hall/ Ballroom/ Auditorium
• Pre-function for Exhibition Hall/ Ballroom/ Auditorium
• Offices
• Kitchen
• M&E Room (MSB Room, Transformer Room, Genset Room, MDF Room, AHU Room, LPG Storage etc)

Again, I would like to emphasize that the very first rule in designing a system is understanding the building. Know the size of your item/ system/ service and check if they are enough room/ space for it.