Lighting System PDF

LIGHTING SYSTEM 1 GENERAL 1.1 Light - The form of electromagnetic radiation that allows the eye to see. It can be a form of natural light and artificial light. Light Spectrum FIGURE 20.2 Classification...

LIGHTING SYSTEM 1 GENERAL 1.1 Light - The form of electromagnetic radiation that allows the eye to see. It can be a form of natural light and artificial light. Light Spectrum FIGURE 20.2 Classifications of electromagnetic radiation spectrum are grouped by wavelength. Shown are the (a) full light spectrum and the (b) visible light spectrum that is part of the light spectrum. One nanometer (nm) is 1/1 000 000 000 meter (m). BEHAVIOR OF LIGHT Illuminance is the amount of light striking a surface. Luminance is the amount of light leaving an object; it is how bright an object appears. The eye sees the visible light leaving an object, not the light arriving at the object. 1. Reflectance – is the ratio of reflected light versus the light striking the surface.  Specular – occurs when light is reflected off a polished or mirror-like surface wherein the reflected image is maintained.  Diffuse – results when reflected light is scattered after striking the surface. 2. Transmittance – is the ratio of light transmitted through the body versus the light illuminating the surface.  Transparent body – transmit light through it without distorting the image (e.g. clear glass)  Translucent body – transmit light but obscures the image because light is scattered (e.g. obscured glass) 3. Absorptance – is the ratio of the light absorbed versus the light striking the surface.  Opaque body – illuminance will be reflected and absorbed but will not be transmitted. COLOR OF LIGHT 1. Color Perception – ability to distinguish and interpret different wavelengths of visible light. The perceived color of an object depends on the dominant wavelength that luminate from it. In natural light, a surface that reflects all wavelengths appears bright while a surface that absorbs all wavelength appears black. 2. Visual Acuity – ability to distinguish fine details; it is the keenness of vision necessary to perform tasks like reading, writing, drafting or surgery. 1.2 Artificial Lighting UNITS OF LIGHT  Luminous Flux – measure of perceived power of light expressed in lumens (lm)  Luminous Intensity – the power emitted by a light source in a particular direction expressed in candela (cd); improperly called as candlepower.  Luminous Efficacy – ration of light output of a lamp into the electrical energy consumed; use to determine efficiency of a bare lamp.  Color Rendering Index – is a method of numerically comparing the color distribution of a light source to a reference lamp. EFFICACY RANGES AND CRI (COLOR RENDERING INDEX) LAMP TYPE RATED POWER EFFICACY MINIMUM CRI (WATTS) (LUMEN PER WATT) Incandescent 10 – 100 10 – 100 100 CFL 3 – 125 41 – 65 80 Linear a. Halophosphate 10 – 40 55 – 70 70 b. Triphosphor 14 – 65 60 – 83 80 Mercury 50 – 2000 40 – 63 20 Metal Halide Up to 1000 75 – 95 65 LPS 20 – 2000 100 – 180 0 HPS 20 – 250 80 – 130 21  Correlated Color Temperature – is the temperature of a lamp in kelvin (k) 1. Warm lighting – less than about emitting mostly red and yellow wavelengths. 2. Cool lighting – greater than about emitting mostly blue and white wavelengths. 3. Daylighting – temperature is between with the lower side warmer and the upper side cooler; noon sunlight; candle frame. Lamp Ave. Efficacy 4 ft. 40 Watt T- Uses 12 (lumens per watt) 1. Daylight 51 Used where color matching is important; equivalent to a north sky; not in general use because of high proportion of blue 2. Cool White 58 Combines high efficacy with good color rendering; used in factories, offices, schools; rather cold in appearance 3. Deluxe cool white 42 Less efficient than daylight by 20%; has better color rendering properties in the long wavelengths; used in stored and some factories where color is important 4. White 59 Highest efficiency lamp; often used in factories and offices 5. Warm white 59 High efficiency lamp; only moderate color rendering; poor with reds – emphasis is yellow and yellow greens; used in offices 6. Deluxe warm white 42 Most efficient lamp; closest approximation to tungsten filament color rendering; suitable for homes, restaurants, hotels. 2 LAMPS  Lamp – device that generates light  Bulb – glass portion of the lamp  Luminaire – complete lighting unit  Fixture – luminaire without the light 2.1 Filament Lamps Produces light by passing electrical current a filament INCANDESCENT LAMPS  Composed basically of a sealed glass containing a filament connected at its ends to the contact area in the base thereby completing an electric circuit.  Emit visible light as a result of heating.  Low cost, reliability, familiarity, good color rendition.  Warm light, poor efficacy, sensitive to voltage fluctuations.  The glass envelope comes in a variety of shapes and sizes; bulb designations consists of a letter to indicate its shape, and a number to indicate the diameter in eights of an inch. The various shapes are: Standard - A Ellipsoidal reflector - ER Reflector - R Globular - G Straight - S Tubular - T Pear-shape - PS Flame - F A PS 30 Lamp therefore is a pear-shaped bulb 30/8 or 3-3/4” in diameter. Types of Glass Bulb Shapes: Types of Bases: TUNGSTEN-HALOGEN LAMPS  The tungsten-halogen  Lamps are hotter-burning incandescent lamps.  These lamps use a halogen gas cycle to prevent rapid depreciation of the lamp filament and darkening of the transparent envelop.  Are similar, brighter, and more expensive version of the incandescent; contains high-pressure halogen gases such as iodine or bromine.  Better color rendition, more light output, and longer life than incandescent.  Easy to control light output.  Warm light.  Generates intense heat, requires good ventilation.  Can shatter if scratched or damaged during installation.  2.2 Gaseous Discharge Lamps Produces continuous light by passing electricity through a gas contained within the lamp; the electric discharge produces ultraviolet radiation that causes a phosphor coating on the inside of the lamp to glow. FLUORESCENT LAMPS  Composed of tubular glass bulb that is covered with thin phosphor coating on its inside surface.  The glass bulb is filled low-pressure mercury vapor; are equipped with filament-like coils at the ends (Cathodes).  All fluorescent light sources require a control device or an auxiliary, called a ballast, located in the metal base; it consumes about 20% energy. The ballast serves as the following functions: -Supplying the high voltage necessary to start the arc; -Limiting the current in the arc after it is formed.  For the operation of fluorescent lamps, an automatic switch known as a starter is required, in addition to the normal wall switch. The starter is self- contained in a small tubular jacket which is inserted in the fixture body and is a replaceable part.  Consumes less energy and longer life span compared with incandescent lamps.  High efficacy; not sensitive to voltage fluctuations.  Hums; longer/larger in size.  Produce a diffuse light source that is relatively glare free and visually comfortable, unlike concentrated light emitted by filament lamps.  Warm light, cool light, daylight, deluxe warm white, soft white Fluorescent lamps are classified as: 1. Linear Fluorescent Lamps (LFL) – available in straight, U-shaped and circular a. T12, T10, T8, T6, T5, T4, T2 are commonly used straight tubes while T9 are used for circular lamps. b. lamps deliver almost the same amount of lumen output for about 20% fewer watts than T12, and have higher lumen maintenance. c. are designed to peak in lumen output at a higher ambient temperature. d. According to the method of tube operation a. Pre-heat  Requires a starter which preheats the cathodes so that less voltage is required to strike an arc.  There is a 2-5 seconds delay in the start of lamp after switch is on.  This class is also called a “switch-start” or “starter-start” lamp.  In certain cases, the started can be eliminated by using a device called a “trigger-start ballast”.   This ballast provides both a current-limiting function and an appropriate automatic starting system. b. Instant Start  When the lamp is first switched on, a sufficient voltage is applied between the electrodes to strike the arc without preheating them.  Instant-start lamps starts as soon as current is turned on and eliminates the need for external starters.  They have single-pin bases which are called “slim-line” lamps. c. Rapid Start  Are the most recent developments and the one that is most widely used.  Rapid-start lamps use low-resistance electrodes which can be heated continuously with low current loses.  These are the only fluorescent lamps that are recommended to be electrically dimmed or flashed. They start as quickly as the instant-start lamps; require no external starters; and the ballasts are smaller and more efficient.  These can be designed with battery pack. 2. Compact Fluorescent Lamps (CFL) – miniature fluorescent lamps; most are now manufactured with integral ballasts.  25 W I – 7W CFL  40 W I – 11W CFL  60 W I – 13W CFL  75 W I – 19W CFL  100 W I – 23W CFL INCANDESCENT TYPES SPIRAL TUBE 3W 5W 5W 7W 7W 11W 9W 13W 11W 15W 15W 20W 20W 23W 23W 25W 25W 28W 65W 65W 85W – above 85W 2.3 High Intensity Discharge Lamps Produces a very bright light by discharging an arc when electrical current passes through a metal gas contained under high pressure in a glass bulb; most HID requires a ballasts and transformer. MERCURY VAPOR (MV) LAMPS  Are the first HID lamps to be developed.  It contains mercury vapor in a clear quartz arc tube, which when electrically excited, produces visible light of characteristically blue-green color.   It is suitable only for limited industrial areas, general outdoor applications and street lighting.  Constructed of internal quartz tube enclosed in a bulb; a small amount of liquid mercury is sealed in an argon gas fill inside the quartz tube.  Low color rendition but phosphor can be added for improvement.  Requires warm-up period.  Higher efficacy than filament lamps.  Longer life span then MH; better lumen maintenance the FL. METAL HALIDE (MH) LAMPS  A modification of the mercury vapor with an arc of improved color.  It possesses therefore increase light output.  Improved color rendition without the use of phosphors, and small sources size.  Constructed similar with MV but with various metal compound mixture (halide) to improve luminous efficacy.  Produces high level of UV radiation.  Life span is shorter than MV.  32W prod. HIGH PRESSURE SOMDIUM LAMPS  Contain an internal arc tube made of translucent ceramic material rather than quartz glass with a small amount of solid metallic sodium and mercury is sealed in a xenon gas fill.  Operates in higher temperature then MV and MH.  Warm-up period is shorter than MH and MV.  Orange-white and orange-yellow light.  Commonly used for outdoor application but can be employed in high ceiling interiors.  Very efficient lumen maintenance.  Longest life span; better efficacy than any other lamp of the same wattage. LOW PRESSURE SODIUM LAMPS  Are blended between HID and FL technologies.  Constructed of a large sodium-resistant glass tube containing sodium and neon-argon gas mixture.  Very low color rendition.  Orange-yellow light.  Shorter re-light time compared to HP.  Efficient lumen maintenance and higher efficacy than MH and MV. 2.4 Solid-State Lighting Refers to a type of lighting that uses light-emitting diodes (LEDS), (OLEDs), or (PLEDs). LIGHT EMITTING DIODE  Provides a desired bright, white, colored and long-lasting light. ideal for retail, feature lighting, ceiling fixture, cove light, etc.  A semiconductor that consists of a chip of semiconducting material treated to create a structure with two electron-charged materials. when connected to power source, electrons jump and emits energy in a form of a proton (light).  The specific color emitted by a LED depends on the materials used to make the diode, red LEDs are based on aluminum arsenide. White light can be achieved by phosphor coating or by RBG system.  Is about a size of pea with high efficacy.  Are ganged together for more light output; a 10W LED produces more light than a 100 W I.  Vibration and shock resistant.  No mercury, no toxic gases and no filament.  Not subject to sudden failure or burnout.  Low voltage and cool to the touch.  Are currently improved for focus lighting reducing the need for reflectors and diffusers. 2.5 REFLECTOR LAMPS Are lamp luminaries with built-in reflecting surface used for incandescent, CFL, HID, or LED. ELLIPTICAL REFLECTOR It is an incandescent lamp with an elliptically shaped reflector. PARABOLIC ALUMINIZED REFLECTOR May use incandescent, halogen tube, HID, CFL, or LED. 3. LUMINARIES 3.1 Luminaries (or Lighting Fixtures) Is the device which supports the source or sources of electric light and redirects or helps to control the light rays from the source. Control of the rays is necessary to secure even distribution, to avoid glare, to cut-off direct rays to the eyes, and eliminates disturbing reflection of the rays from polished surfaces. CLASSIFICATION OF LUMINAIRES 1. DIRECT – 90% - 100% of the light output is directed downwards. 2. SEMI-DIRECT – 60% - 90% of light is directed downwards; while 40% to 10% is directed upwards. 3. GENERAL DIFFUSE OR DIRECT-INDIRECT – provides approximately equal distribution of light upwards and downwards. 4. SEMI-INDIRECT – 60% to 90% of the light is directed upwards; 40% to 10% downwards. 5. INDIRECT – 90% to 100% of the light output is directed towards the ceiling and upper walls of the room. 3.2 Luminaries Lighting Systems 1.CORNICE LIGHTING – a system where light sources are shielded by a panel parallel to the wall and attached to the ceiling to distribute light downwards over the wall. This is considered as direct lighting. 2.COVE LIGHTING – a system where light sources are shielded by a ledge to distribute light upwards over the ceiling and upper wall. It is a form of indirect lighting. 3.VALANCE LIGHTING – a system where light sources are shielded by a panel parallel to the wall usually across the top of a window. This provides light both upwards and downwards over the wall. 3.3 Commercial Type of Luminaire 1.CEILING MOUNTED DOWN LIGHTS:  Luminaire that is usually attached (surface-mounted) to or recessed in the ceiling and emits concentrated light downward.  Down Light – a fixture producing concentrated direct lighting form a single bulb. It may be recessed in or mounted on the ceiling.  Eye ball – recessed or semi-recessed lighting unit with a rotating spherical element that may be turned to project light in any direction.  High Hat – a term often applied to a can-type of recessed incandescent downlight.  2.PARABOLIC ALUMINIZED REFLECTOR (PAR)  Sometimes called  Made of two glass parts; one is the reflector welded together.  Because of the more precise parabolic control, PAR lamps are sometimes aimed into a tight beam designed to hit a specific object or a smaller surface area. Such lamp is designated as a spot. 3.DIRECTIONAL LIGHTING  Spotlight – luminaire designed to emit an intense, concentrated beam of light usually no more than 20 degrees spread from where it is directed.  Floodlight – a luminaire that emits intense light that is broader than a spot light and is capable of being pointed in any direction.  Track light – a directional lighting where luminaires are attached to and are moveable along a metal track. 4. PENDANTS  A luminaire that is hung with a cord, chain or tube that enables it to be suspended from a ceiling.  Low Bay – are designed for low to medium ceiling areas.  High Bay – luminaires used in high ceiling areas that require uniform illumination. 5. WALL WASHERS/WALL SCONCE/WALL LIGHTS:  Decorative, wall-mounted luminaires that provide ambient illumination by directing light upward, downward, or in all direction. 6.TASK AND TABLE LIGHTS 7.FLOOR LIGHTS: 8.EXTERIOR LIGHTS: 9.FLUORESCENT LUMINAIRES: WATTAGE DIMENSION 4 X 36/40 W 24 X 48 IN 3 X 36/40 W 24 X 48 IN 2 X 36/40 W 12 X 48 IN 1 X 36/40 W 12 X 48 IN 4 X 18/20W 24 X 24 IN 3 X 18/20 24 X 24 IN 2 X 18/20 24 X 24 IN 1 X 18/20 W 12 X 24 IN 4 LIGHTING DESIGN 4.1 Methods of Architectural Lighting Basic functions that light performs in interior building spaces  AMBIENT LIGHTING OR GENERAL LIGHTING – Provides uniform illumination throughout the space.  LOCAL LIGHTING – Illumination provided for a specific visual function which is additional to and controlled separately from ambient lighting  TASK LIGHTING – A type of Local lighting specifically for precision works.  ANCIENT LGITHING (FOCUS LIGHTING) – Is directional lighting used to emphasize a particular object or area.  DECORATIVE LIGHTING – A type of accent lighting wherein the light source that adds a quality of interest to the space. 4.2 Emergency and Safety Lighting It is a secondary lighting system that provides backup and illumination when power supply is interrupted or fails.  EMERGENCY LIGHTING – Required in critical care and emergency spaces and emergency spaces in hospitals, fire protection, nursing homes.  STAND-BY LIGHTING – Part of the emergency lighting that enables normal activities to continue substantially unchanged.  SAFETY LIGHTING – Part of the emergency lighting that ensures safety of people involved in potentially hazardous process.  ESCAPE LIGHTING – provides illumination to ensure that an escape route can be effectively identified and used in event of normal power failure or interruption.  EXIT LIGHTING – Part of escape lighting that includes illuminated signage used to provide clear directions for an emergency exit of a building. 4.3 Factors which will achieve desirable seeing conditions INTENSITY OF ILLUMINATION Intensity of light required will depend upon the tasks involved as follows: - For casual work, as in conferencing, interviewing and inactive filling – 10 to 30 fc - For moderate work, as in intermittent filling and general clerical work – 30 to 50 fc - For prolonged work, as in active tiling, index referencing and mail sorting – 50 to 100 fc - For precision work, as in accounting, auditing, tabulating, bookkeeping, business machine operation, reading poor reproductions and rough layout drafting – 100 to 150 fc - For fine precision work, as in cartography, designing and detail drafting – 150 to 200 fc  AVERAGE LIGHT LEVELS FC Hotel hallways, stairs 2.5 – 5 Office hallways, parking garages, theatres 5 – 10 Building Lobbies, Waiting Areas, Elevator Lobbies, Malls, 10 – 20 Hotel Function Rooms, School Corridors Office areas, classrooms, lecture halls, conference 20 – 50 rooms, retail lighting, industrial workshops, gyms Grocery, big box retail stores, laboratories, work areas, 50 – 100 sport courts 5 fc is 50 lux 1000 fc is 10, 000 lux 1 fc is 0.76 lumens / sq. m RECOMMENDED DESIGN ILLUMINATION LEVELS TASK MIN & MAX (LUX) APPLICATION Lighting for infrequently 50 – 100 Circulation areas & used areas corridors 50 – 100 Stairs 100 – 200 Hotel, Escalators Lighting for working 300 – 750 General offices, typing and interiors computing 300 – 750 Conference room 500 – 1000 Deep-plan general offices 500 – 1000 Drawing offices Localized lighting for 750 – 1500 Designing, architecture exacting tasks and machine engineering 1000 – 2000 Detailed & Precise Work QUAILITY OF LIGHT Light Distribution depends upon: 1.Uniformity  Freedom from variations of illumination in a room or space  Absolute uniformity signifies same intensity throughout and it is not always practicable to attain.  A deviation of 25% from the average intensity cannot be detected by the eye, and is considered an acceptable maximum. 2.Diffusion  Refers to the number of directions and angles from which illuminating rays proceed.  Good diffusion is obtained when light fall upon a matte or satin surface from a variety of directions thus eliminating shadows and streaks of brilliancy.  Poor diffusion result from illumination from one direction only thus causing visual confusion because of distorted highlights and shadows. 3.Absense of Glare  Glare is defined as the effect of brightness in the field of vision which causes annoyance or discomfort, or in worse cases, interferes with seeing.  Discomfort Glare- visual discomfort without necessarily impairing vision.   Disability Glare- occurs when visibility is impaired from excessive brightness.  Bare lamps or brilliant fixture globes should never be in the line of sight from any point in the room.  An angle between the horizontal and the line of sight (line from the lamp to the eye) is generally accepted as the greatest permissible angle. 4.Color of Light  Depends upon the type of lamp chosen.  Incandescent lamps provide yellow light; although these are many other colors depending upon the color of their glass bulbs.  Fluorescent lamps have the greatest variety of colors ranging from daylight to bluish white and even pinkish white.  Color is also used to enhance certain qualities. For example, deluxe FL lamps are used to enhance food in restaurants. 4.4 Natural (Daylighting) Lighting GENERAL SOURCES OF DAYLIGHT 1. SUN  Effectivity of the sun as a light source is affected by its position in the sky in the course of the day, rotation of the earth about its axis, revolution of the earth around. 2. SKY  In reality a hemisphere of differing brightness; it is brighter above than below 1  Overcast sky is 22 to 3 times as bright above.  Illumination = 500 lumens/sq.feet regardless of location and orientation 3. GROUND  Light reflected from the exterior ground commonly represents 10-15% of the daylight reaching the interior area.  Ground as daylight source is difficult to control because of factors that are variable; affected by orientation, weather, time of day, season of the year, etc. DAYLIGHTING TYPES 1. Direct Light- travels in a straight line path from the sun and tends to be more intense than diffuse and reflected light. 2. Reflected Light- strikes a surface and reflects off the surface in another direction. 3. Diffuse Light- is light that has been reflected by clouds, glazing, or skylights. DAYLIGHTING METHODS 4.5 Lighting Terms 1. Absorption- Loss of light when light rays strike or transverses any medium. The ratio of light absorbed by a material to the light falling upon it is called the “absorption factor” or “absorptance”. 2. Capacitor-an electric component which consists of conducting plates insulated from each other by a layer of dielectric material; introduces capacitance into a circuit. Capacitance is the quantitative measure of the electric-energy storage capability of a capacitor; usually measured in farads or microfarads. 3. Diffuse light- is light that has been reflected or refracted by clouds, glazing, or skylights 4. Diffuse reflection- a beam of light is reflected diffusely, that is, its ray is scattered in all directions, if it strikes a rough or matte surface. 5. Dimmer- a device to control the amount of light by reducing the voltage or the current; also called a “rayostat” 6. Direct Light- travels in a straight line path from the sun and tends to be more intense than diffuse and reflected sunlight. 7. Filament- the threadlike conductor of an electric lamp that is heated to incandescence by the passage of an electric current. 8. Filter- device which changes either amount of color, or both. Of light passing through it. 9. Illumination- amount of light falling on a surface; a measure of light flux density. 10. Incandescence- the emission of visible light by a body when heated to a high temperature. 11. Lumen Method- method used for calculating illuminance levels in uniform situations; also called Zonal Cavity Method. 12. Lumiline- a tubular fluorescent lamp with a disc base at each end. 13. Luminance- quantitative measure of brightness of light source or an illuminated surface; photometric brightness and is luminous flux (light) being emitted, transmitted, or reflected from a surface. 14. Luminance Ceiling- a false ceiling of diffusing material with light sources method. 15. Munsell System-a system for cataloging colors based on the smallest discrete increment of color change recognizable by a human. The Munsell system uses hue, chroma, and value to organize the complete range of possible colors. 16. Photometrics- the data that describes the beam characteristics of a lamp or lap fixture. 17. Reflectance- also called “reflection factor”; it is the ratio of light reflected by a surface to the light falling upon it. (usually expressed as a percentage) 18. Reflected light- strikes a surface and reflects off the surface in another direction. 19. Refraction- the process by which light is bent when passing from one medium to another. 20. Spectrum- a range of electromagnetic radiation usually referring to a portion of what is within the visible range. 21. Specular reflection- a beam of light is secularly reflected when a light ray striking a shiny or glossy surface at an angle of incidence is reflected as the same beam with equal angle of reflection; a reflection that retains the original image. 22. Transmission- is the passage of light through a medium when light falls upon a transparent material. It is “refracted” (bent) as it passes through the material but emerges at the same angle that it entered. When passing through a translucent material, such a s plastic, and the emerging rays are spread in all directions, it is called “diffused transmission”. 23. Transmittance- also called “Transmission factor”. It is the ratio of light transmitted to light striking the surface; equivalent to 1 minus the absorptance. 24. UL approved- means that Underwriter’s Laboratories, an independent testing agency, has tested representative samples of the labeled device and has certified that it meets the criteria of the classification for which it is labeled. The Canadian equivalent is the CSA, or Canadian Standards Association. 25. Valence- long source of light over a window / its light illuminates the wall and draperies for spacious effect. +EFFICACY – ratio of luminous output to input power in watts (lumens per watts) Low Pressure Sodium- up to 180 High Pressure Sodium- 75 to 140 Metal Halide- 80 to 100 Fluorescent- 55 to 100 Mercury- 50 to 60 Tungsten Halogen- 15 to 25 +LIFEHOURS 1. HPS (longest) - HIGH PRESSURE SODIUM 2. MV – MERCURY VAPOR 3. LPS – LOW PRESSURE SODIUM 4. FL - FLUORESCENT 5. MH – METAL HALIDE 6. TH – TUNGSTEN HALOGEN +RELIGHT TIME Low Pressure Sodium – Immediate Fluorescent – Immediate (Rapid and instant start) Tungsten Halogen – Immediate High pressure Sodium – less than a minute Mercury – 3 to 10 mins. Metal Halide – 10 to 20 mins. +FIXTURE COST (Highest to Lowest) High pressure sodium – 1 Low pressure sodium – 2 Metal Halide – 3 Mercury – 4 Fluorescent – 5 Tungsten Halogen – 6 +OPERATING COST (Highest to Lowest) 1 – High pressure sodium 2 – Low pressure Sodium 3 – Metal Halide 4 – Metal Vapor 5 – Fluorescent 6 – Tungsten Halogen +LIGHT DIRECTION CONTROL Tungsten Halogen – V6 to Excellent High Pressure Sodium – V6 Metal Halide – V6 Mercury – V6 Low pressure Sodium – Fair Fluorescent – Fair +LUMEN MAINTENANCE 1 – HPS 1 – LPS 2 – MV 3 – MH 4 – FL 5 – TH MECHANICAL AND ELECTRICAL SYSTEMS 4. FIRE SAFETY PRICIPLES 4.1 Definition and Causes of Fire  Fire is a rapid oxidation process accompanied by the evolution of heat, light, flame, and the emission of sound.  The Fire Triangle: Three elements – fuel, oxygen, and heat – are required to start a fire. The oxidation process will not be possible without any of these elements. 4.2 Classes of Fire CLASS Fire Involving How to Suppress A Ordinary combustible Use water materials such as wood, cloth, paper, rubber, and plastics, etc B Flammable or Exclude air from combustible liquids, burning materials flammable gases. C Energized electrical No water; equipment Use electrically non- conductive extinguishing agents such as gaseous systems D Combustible metals Heat- absorbing such as potassium, medium which is not sodium, magnesium reactive with burning and other reactive metals materials  4.3 Fire Growths STAGES 1 Pre-Flashover or Involves flaming growth phase combustible of an item and may lead to a spread of fire; or a smoldering, poorly- ventilated fire with substantial smoke. 2 Flashover Rapid change from a local fire to one involving all combustible materials in a room. 3 Fully developed fire All materials in (Stable phase) compartment are alight; maximum rate of heat release is dependent on either available ventilation or quantity of fuel 4 Decay (Cooling Gradual consumption Period) of fuel in the compartment. Architectural Intervention during Fire Growth  This graph shows where active and passive fire protection will play an important part during the development of fire. 4.4 Behavior of Fire and Smoke 4.5 Fire Squad Internal Fire Spread due to: External Fire Spread due to:  4.6 Aims in Fire Safety Design  To prevent fire  To safeguard the lives of occupants and firefighters  To reduce damage on the building, its contents, and on surrounding buildings 4.7 Basic Principles ARCHITECTURAL FIRE SAFETY PRINCIPLES AS APPLIED TO EGRESS DESIGN CONSIDERATIONS The key to study of architectural fire safety is primarily, to study how to prevent fire; secondly, how to control it, in order to lessen material damage; and thirdly, how to avoid the loss of valuable lives. 1. Fire prevention techniques are basically architectural design techniques which require the handling of spaces and materials in order to prevent fire from occurring, 2. Fire control techniques can be broken down into active and passive methods. Active methods rely on mechanical and electrical engineering systems, such as the use of fire hoses and the automatic sprinkler systems. On the other hand, passive methods of fire control are inactive techniques which are basically aimed at retarding the growth and spread of fire through the architectural use of materials and methods of construction. 3. Lastly, lifesaving systems generally traces five escape routes and proposed techniques for fire escape. The principles of architectural fire safety design, according to England’s Department of Health Social Services “Hospital Building Notes” , can be divided into two main categories are enumerated as follows: 1.) Principles which involve the handling of fire a. Fire Avoidance b. Fire Growth Restriction c. Fire Containment d. Fire Control 2.) Principles which involve the saving of lives in a fire emergency situation a. Fire detection b. Smoke Control c. Escape Provisions A. Fire Avoidance Fire prevention or avoidance is reducing the possibility of accidental ignition of materials of construction, as well as, the building’s contents, furniture and fixtures (DHSS). These are the general factors to consider in the design of hospitals to avoid the accidental start of a fire or to prevent its sustenance. 1. First, is the use of construction materials which are non-flammable. 2. Second, is the avoidance of the use of furniture and interior accessories which will increase the building’s fire load; 3. Third, is ensuring that electrical installations follow recognized standards and good industry practice; 4. Fourth, is the provision of sufficient number of convenience outlets to avoid “octopus’ connections” with many extension cords; and 5. Fifth, through efficient fire planning and zoning, keeping separate the heat sources from combustible finishing and interior materials. The spaces in a hospital, for example, can be categorized into four fire zones as follows:  High Fire Risk Zone is composed of spaces which due to their functions and operations are more susceptible to an outbreak of fire or to a rapid spread of fire  or smoke (DHSS). The main kitchen and the boiler room in a hospital are examples of high fire risk areas.  High Fire Load Zone is composed of spaces which because of their construction or contents, contain large amounts of combustible materials, thereby constituting a fire load in excess of the normal load (DHSS). The gas storage room and the linen closet are examples of high fire load areas.  Life Risk Zone is composed of spaces in which all patients are ambulant and are able to move unaided away from a fire (DHSS). The Outpatient Department and the Services Areas are usually as life risk areas in the hospital.  High Life Risk Zone is composed of spaces in which patients may not be able to move unaided away from a fire (DHSS). The Intensive Care Unit, the Surgical Ward and the Operating Suite are examples of high life risk areas in the hospital. With the proper zoning of the hospital’s spaces during the design stage, these important objectives can be achieved:  Incompatible areas can be separated from each other by distance or by a fire- rated barrier wall. For example, the ICU must be physically separated from the main kitchen.  Non-ambulant patients will be assured of less fire risk, proper egress and sufficient time to evacuate by separating them from the high fire risk and high fire load areas.  Access of firemen to high fire risk and high load areas can be ensured for more efficient fire control. B. Fire Detection Fire detection makes use of visual and mechanical methods of alerting the occupants of the hospital that a fire has occurred in a given location (DHSS). The factors to consider to ensure fire detection are: 1. High Fire Risk and High Fire Load Areas should be visually accessible to the hospital occupants walking along the corridors and not hidden from view. 2. Fire, heat and smoke detectors should be provided especially in high fire risk and high fire load areas. 3. Fire alarm systems should be highly accessible and visible in order to signal the group of occupants that most require it during an emergency. Early detection of fire and early signal to other occupants will mean more chances of ambulant and non-ambulant patients to evacuate to a place of safety. C. Fire Growth Restriction Fire growth restriction is actively extinguishing fire or slowing down the development of a fire before full involvement of the room by the room’s local occupants (DHSS). Its aim is to ensure that the growing fire is extinguished immediately or at least is slowed down in order to provide time for the firemen to arrive, control the fire and evacuate the occupants. The means to restricting fire growth is as follows: 1. Manual means, by the use of local firefighting equipment, as fire extinguishers, fire blankets, water, and buckets of sand. Designing for fire growth restriction will mean the assurance that all this local equipment is immediately available for use and are so located that all areas in the hospital, especially the high fire risk and high fire load areas shall be cover adequately. 2. Automatic means, by the use of fire sprinkler systems, which are the frontline defense for hospital fire suppression in appropriate areas. D. Fire Containment Fire containment assumes that measures to control a growing fire may not be successful, hence its maximum size needs to be restricted, in order to reduce the risk, lessen facility, material and equipment damage and allow effective firefighting (DHSS).  The means to effectively implement the concept of fire containment are described as follows: 1. The use of fire rated walls and slabs to contain fire in a room, sub compartment and compartment which are zoned as high fire risk and high fire load areas in order to segregate these areas in case of fire. 2. Fire cladding the hospital’s structural components to ensure the structure’s stability and to prevent its collapse. 3. Fire cladding the hospital’s protected escape routes, firemen’s access routes/shafts and places of safety, to ensure their stability, integrity and insulation so that successful evacuation can be assured during times of emergency. 4. Plugging of all holes to prevent fire and smoke from penetrating into adjacent areas, extending the CHB walls up to upper slab, provision of a minimum one- meter ledge to prevent fire from creeping walls into floor above through windows. E. Fire Control Fire control covers those devices and systems which aid firemen in actively extinguishing the fire and bringing it to an end earlier than a free burning fire (DHSS). Fire control is implemented as follows: 1. Provision of a complete and rapid access for the Fire Department apparatus to all parts of the site, around the hospital’s exterior and all of the spaces inside building. 2. Since fire truck ladders have limited height capabilities, protected fire shafts are provided in multi-story buildings complete with facilities, equipment and amenities for fighting upper story fires. 3. Firefighting equipment are placed in strategic protected locations, rapidly accessible to firemen, on the site, and in building interiors. 4. All areas inside and outside the hospital building are covered by the reach of the fire hose. F. Smoke Control Smoke Control includes measures to reduce the hazard due to smoke by controlling its movement and by reducing its concentration to increase visibility (DHSS). Techniques of smoke control include the following (DHSS): 1. Smoke Containment is the technique of restricting movement of smoke by the provision of fire resisting elements. 2. Smoke dispersal is the technique of clearing smoke locally by the provision of natural cross ventilation or mechanical venting. 3. Pressurization is the technique whereby air is blown into spaces which are desired to be kept clear of smoke. The basic objective of smoke control is to free the burning building interiors of smoke, especially the designated access and escape routes in order that firemen may enter the building to fight fire and the occupants may be able to evacuate from the building without danger of suffocating from the smoke. G. Escape Provisions Escape Provisions cover a range of passive or active system which permit the occupants to move or be moved to a place of safety within or to the exterior of the hospital. These include: 1. The correct design of the corridor system as a protected means of escape. This will mean that corridors must be direct, not tortuous; with a simple lay-out; no barriers, cul- de-sacs, bottlenecks; limit dead-ends; doors should open out to the escape corridor and not in; must be easily detectible and not hidden from view; and must be compartmentalized. 2. The correct design of the fire escape stairs as a protected means of escape. The fire escape stair should be designed to be used daily for familiarity of escape route; well maintained and not used to store junk and must be compartmentalized. 3. The protected escape routes shall be delineated and designed as such.  4. Each sub compartment and compartment should have an alternative means of escape opening to a place of safety. This will mean the provision of a second exit door which shall be located in an opposite direction farthest from the first exit door and/or the provision of adequate number of exits based on building occupancy regulations. Fire exits shall be clearly recognizable with signages and emergency lighting. 5. The fire resisting doors of sub compartments and compartments should be correctly designed as to their width, fire rating, and the direction of their swing. 6. A place of safety is a compartmentalized space which can serve as a temporary place of refuge away from the burning compartment. The exterior of the hospital is the ultimate place of safety. 7. Evacuating patients and staff in a fully compartmentalized hospital will afford an organized group evacuation of the departments and the wards using the concepts of “progressive horizontal evacuation”, wherein the group can leave the hospital by leaving horizontally and vertically into places of safety within the hospital until they reach the exterior of the hospital. 4.8 Definition of Terms 1. Fire damper- a damper that closes an air duct automatically in the event of fire to restrict the passage of fire and smoke. 2. Fire pump- a pump that provides the required water pressure in a standpipe or sprinkler system when the pressure in the system drops below a pre-selected value. 3. Fire zone- a zone of a city within which certain construction types are prohibited because 4. Fire Retardant- a compound used to raise the ignition point of a flammable material, thus making it more material. 5. Flame-spreading rating- a rating of how quickly a fire can spread along the surface of an interior finish material. 6. Flash point- the lowest temperature at which a combustible liquid will give off sufficient vapor to ignite momentarily when exposed to flame. 7. Fusible link- a link made of a fusible material. When exposed to heat of a fire, the link melts and causes a fire door, fire damper, or the like to close.