P/00/011 Regulation 3.2 AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION INNOVATION PATENT Safety Way Guidance and Emergency Escape Lighting System and Unit The following statement is a full description of this invention, including the best method of performing it known to us: 1 Title: Safety Way Guidance & Emergency Escape Lighting Method and Unit Field of Invention 5 The field of the invention relates to the safety of building occupants during a forced evacuation caused by fire, smoke or Hazmat (Hazardous Materials) events, terrorist or bomb threats, power outages, natural disasters such as cyclones and the like. In particular the invention creates a visually trackable o and directional safety way guidance system along an escape path to speed occupants' orderly egress to the nearest internal refuge or fire exit in clear air and in progressively accumulating fire smokes or other toxic airborne contaminates. 5 Background In Australia, emergency lighting is generally provided in the form of a dedicated ceiling mounted luminaire at spacing's based on the lit classification the luminaire achieves at test. AS 2293.1.2005 is a standard mandated by the o Building Code of Australia (BCA) and sets out a classification test and a table of maximum spacing (in meters) for tested classifications of luminaires at specific mounting heights measured from floor. This ensures an emergency luminaire will achieve a minimal level of emergency illumination when normal lighting fails i.e. mains failure. The minimum level of emergency illumination is 5 0.2 Lx at floor level and must be provided for not less than 120 minutes after power fails in normal day to day use. This lit standard applies to all parts of the buildings environment i.e. open areas and escape path(s). This type of emergency lighting design cannot provide directional information. 30 Since the mid 1970's compliant emergency luminaires commonly used in Australian buildings comprise a non-maintained lighting unit (lamp assembly) constructed of metal or plastic discs, generally 65 to140mm diameter, with a 10 W halogen bulb mounted in a slightly recessed centre. Generally the bulb protrudes approximately 5mm below the ceiling level and is easily damaged, 35 removed or vandalized. These lighting units are installed into ceilings and clearly visible throughout a building and are in addition to normal overhead lighting. 2 This lighting unit is connected by wiring looms to the other components of the luminaire consisting of an inverter, battery charger, electronic control gear and a rechargeable battery pack i.e. uninterruptible power source (UPS) all of which make up the complete emergency luminaire. These other components 5 are normally not visible installed above the ceiling and connected to an unswitched active mains electricity circuit(s) above the ceiling. Should mains power fail or be disconnected for example by attending fire and rescue services in an emergency, this is sensed by the inverter which immediately switches to the rechargeable battery pack/UPS to provide emergency lighting. 0 Further the lighting unit must provide a visible signal which indicates either normal operation of the emergency luminaire or failure. This visible signal is generally provided by a small illuminated (3mm) LED which may be red or green and is separate from the main light source. In normal operation the LED 5 signal would be on. If this signal is not visible it indicates the charger of the luminaire, or other critical component has failed and the luminaire is no longer operational. The term "non-maintained emergency luminaire" is a standardized industry o description for a normally unlit but powered luminaire, which can energize the light source utilizing the battery pack/UPS supply i.e. after mains failure or disconnection. The above references to and descriptions of prior proposals or products are 5 not intended to be, and are not to be construed as, statements or admissions of common general knowledge in the art in Australia. Summary 30 In one aspect the invention relates to combined emergency lighting and safety way guidance system for a built environment said system comprising a plurality of lighting units, each lighting unit comprising: a) a first light source which emits light of a first color and is activatable in an emergency; b) a second light source which emits light of a second color for wayfinding; and c) 35 a third light source which emits light of a third color which indicates operational status of the unit wherein said lighting units are located at suitable intervals and characterized in that the second light source when powered in non-emergency conditions constantly emits light of the second color enabling a person to learn the escape path(s) prior to an emergency and optionally 3 where the second light source flashes on/off in the initial stages of an emergency enabling a person to find and follow the escape path(s). The term "emergency lighting" refers to non directional lighting which is 5 activated during a power failure or where the mains power supply has been disconnected by fire and rescue. This type of lighting is generally mandated by building codes as described earlier. The term "safety way guidance system" refers to a system by which a person o may be guided safely from a built environment using visual cues. Thus the invention results in escape path directional lighting. The term "escape path directional lighting" refers to a system of conspicuous and unambiguous lit visual cues along an escape route which a person can follow, this being a path(s) leading to the fire exit(s) or internal refuges of a building and also 5 includes wayfinding. Generally the escape path will be determined by the fire safety engineering plan based on building usage, occupancy and BCA deemed to satisfy requirements. Alternative engineered solutions to deemed to satisfy requirements are commonplace provided they meet or exceed the deemed requirements. 0 In an emergency an audible non-directional alarm is activated either manually or automatically at the commencement of an emergency evacuation. The emergency lighting is not required to be activated in conjunction this audible alarm. Thus in the initial stages of an emergency the emergency lighting is not 5 switched on and may not be switched on until power fails or is disconnected some considerable time after the building evacuation commenced. The term "built environment" refers to any built structure and includes structures such as homes, offices, schools, high-rise buildings both residential 3o and commercial, shopping centers, entertainment and sports venues, hospitals, nursing homes, factories, cinemas, theatres, hotels, hospitals, pubs, road tunnels, railway stations particularly underground railway stations and the like. 35 The term "plurality" means more than one lighting unit. The term "lighting unit" refers to a lamp assembly capable of energizing and/or controlling a light source. Preferably the lighting unit is capable of directing a light source to provide wayfinding and emergency lighting. 4 Preferably the lighting unit used in the invention is provided as part of a luminaire. The term "light source" refers to the element which is capable of emitting light. 5 These light sources may be in the form of different types of incandescent or halogen bulbs, fluorescent tubes and light emitting diodes (LED's) sources. Preferably the lighting unit comprises a tri-coloured LED design which has up to 3 independently controlled LED's encapsulated in a single epoxy or silicon plastic dome shaped lens/casing, mounted onto a star shaped metal base. o The 3 LED's may be lit separately or simultaneously. This tri-coloured design has been developed to provide the dual functions of emergency lighting and safety way guidance or wayfinding. The first light source emits the first color which is preferably that mandated 5 and/or approved by a regulator. Generally this color is white in Australia. Optionally the color may be green which is more visible in fire smoke conditions and assists in more clearly identifying an escape path. The term "activatable" in an emergency means that the first light source is o able to be activated the mains power fails or is disconnected. Preferably the first light source is activated immediately the mains power fails or is disconnected. The second light source emits a second colour and is preferably powerable by 5 mains power. Preferably the second color is green. The term "indicates operational status of the unit" means that the third light source indicates whether the lighting unit is functioning correctly or whether it needs repair or maintenance. 30 The third light source is preferably recognized as indicative of the failure of the BCA mandated 6 monthly duration test failure (i.e. the emergency luminaire shall be able to provide minimum level of emergency illumination for 90/120/180 minutes energized solely by battery pack/UPS). The colour of the 35 third light source is preferably red and flashes on/off every second for a period of 7 days to warn that the luminaire requires compliance checking/service. The term "located at suitable intervals throughout the environment" means that the units are positioned relative to each other so as to delineate the 5 escape path(s). This means that each unit is within the line of sight of the next unit of a person following an escape path(s) and that the spacing of the units is such that the next unit in the series is visible under low light conditions as a person makes their way along the path(s). This provides a tracking function 5 for a person. Preferably the lighting units are located at 8m to 12m centers along the ceiling or other suitable structure of the built environment. The term "the second light source when powered in non-emergency conditions constantly emits light of the second colour" refers to the second o light source being in operation constantly provided power is available, 24 hours a day prior to an emergency. This enables people using the built environment daily, to learn the escape path and further may be used in fire drill training awareness. When the mains power fails or is disconnected by fire and rescue services in an emergency, the second light source ceases to emit 5 light. Preferably the second color is indicative for wayfinding. Preferably this color is green. Preferably, in the event of a fire alarm activate signal being received by the control gear of the luminaire (in conjunction with audible fire alarms of the o building) and prior to mains power failing or being disconnected, the intensity of the second color can be increased and the light can be alternatively flashed on and off at intervals. For example in non emergency conditions the light can operate at a relatively low intensity to avoid glare; whereas in the initial stages of an emergency evacuation the light intensity can be substantially increased 5 and be flashed on and off at intervals of 1 second until a fire alarm de-activate signal is received by the control gear of the luminaire or mains power fails or is disconnected and the emergency lighting function is activated. The "activate and de-activate" fire alarm signals are normal part of a fire control panel system mandated for the built environment. The 1 second on/off cycle has 3o been chosen to avoid inducing epileptic fits in susceptible individuals. Preferably the light intensity and other qualities of the light emitted by each coloured LED light source, such as flashing/non-flashing are individually controlled for each coloured LED. Up to 3 different coloured LED's can be 35 individually controlled in the tri-coloured design. Further in a broader aspect the invention relates to a method of providing wayfinding of an escape path(s) for a person in a built environment said method comprising provision of lighting units which while connected to mains 6 power will constantly emit a wayfinding indicative light in normal and in low light conditions; said units alternately powerable by rechargeable battery pack/UPS, being located at suitable intervals throughout the environment to mark direction(s) of said escape path(s) wherein the wayfinding indicative light 5 is different from other lighting in the environment allowing a person to learn the path(s) prior to, or in an emergency situation requiring an evacuation. The term "wayfinding" refers to a person finding their way to an escape path to allow them to follow that an escape path(s) to a fire exit or internal refuge in o the built environment in timely and safer manner. The term a "wayfinding indicative light" means a light that indicates the way to the nearest fire exit or internal refuge in a built environment. Preferably the wayfinding indicative light is distinguishable from other normal lighting in the 5 environment, the other light sources being white light from artificial lighting (fluorescent lights, etc) daylight and other white light sources. The wayfinding indicative light may be green or another suitable colour approved by the regulator. o The term "normal lighting" refers to when the building is normally lit by a combination of standard artificial light and daylight during the day or normal artificial light at night. The term "low light conditions" refers to where normal lighting conditions are absent or caused by a power failure or disconnection when emergency lighting is activated and in smoky conditions. 5 The term "alternately powerable by rechargeable battery pack/UPS" means that each unit is powered by mains but is able to switch to its rechargeable battery pack/UPS should mains power fail or be disconnected. Alternatively, the lighting units will then energized by its battery pack/UPS. 30 The invention also relates to a method of facilitating learning an escape route or routes in a built environment, said method comprising: providing lighting units which while powered constantly emit a wayfinding indicative light in normal and in low light conditions, said units powerable by batteries, an 35 uninterruptible power source separate from mains power, said units being located at suitable intervals throughout the environment to mark said escape path(s) wherein the wayfinding indicative light is different from other lighting in the environment allowing a person to learn the escape path(s) prior to, or in an emergency situation requiring evacuation of the environment. 7 The term "facilitating learning" refers to promoting or assisting learning or knowledge of an escape path(s). 5 Preferably in both of the above methods the wayfinding and learning escape path(s) functions are combined with an emergency lighting system. This is advantageous because it allows use of the existing emergency lighting points in a building to be retrofitted and upgraded to provide a wayfinding function. o Although closely related issues, evacuation procedures and emergency lighting systems have operated quite separately. Traditionally emergency lighting has been employed under quite a different philosophy to that of fire alarm systems. This is in part caused by the different wiring requirements of systems. The components of a fire alarm system such as smoke and heat 5 detectors, fire alarms, etc are generally hardwired (24V) back to the fire control panel which has series of relays to energize or activate/deactivate alarms. The fire control panel has its own UPS. Emergency lighting is generally hardwired on an unswitched active 220-240v lighting circuit and each emergency luminaire contains a rechargeable battery pack/UPS. 0 As will be appreciated it may be necessary to evacuate a building for a number of reasons such as when smoke activates the fire alarm, heat activates the fire alarm or when a person activates the fire alarm by breaking the glass and pressing the emergency fire button. It may also be necessary to 5 evacuate the building in the case of a bomb scare or other threat. The first five minutes in an evacuation procedure is considered to be crucial to an individual's safety. If building occupants 'do not start moving out' of the building within this first five minutes then their required estimated time to evacuate, may exceed the available estimated time to evacuate anticipated in 30 the buildings evacuation plan and their chances of injury are greatly increased. The advantage of the present invention in one of its preferred forms is that during that first period of an emergency, before emergency lighting operates 35 and when normal lighting is on, it can be used to visually alert people and start the evacuation process in conjunction with the audible fire alarms and importantly provide individuals visual directional and tractable cues along an escape path(s) to the nearest fire exit or internal building refuge. 8 In a preferred form the invention provides vital links between safety way guidance, wayfinding, emergency lighting and a building's audible alarm systems. 5 The invention also provides a lighting unit for use in the system and method. Thus in another aspect the invention provides a combined emergency lighting and wayfinding guidance unit comprising: a) an emergency lighting component which in use, is able to emit a first light source comprising a first o colour and is activatable in an emergency and; b) a wayfinding guidance indicator lighting component; wherein the indicator lighting component is able to emit light of a second colour and is indicative of a buildings escape path(s) when a plurality of said units is installed in a built environment to indicate an escape path(s) from said environment characterized in that in use in non 5 emergency conditions the wayfinding component is able to, while powered, constantly emit light of the second color enabling a person to learn escape path(s) prior to an emergency and optionally is able to flash on/off at least in the initial stages of an emergency enabling a person to find and follow an escape path(s) during an emergency. 0 The term "wayfinding guidance" refers to the ability of the unit to assist a person in finding an escape path(s). Preferably the combined emergency lighting and wayfinding guidance unit is 5 for use in a luminaire. Preferably the first colour is white and the second colour is green. Preferably the first and second light sources are provided by the Multi 30 coloured LED design. More preferably the intensity of the first and second colours is controlled individually or separately. This is preferably achieved by supply of current to the relevant coloured LED in the range of about 15mA to 350mA. 35 Preferably the lighting unit of the invention comprises a combined reflector and heat sink present in a single housing design. Even more preferably the tri coloured LED emergency lighting and wayfinding component is recessed within the heat sink. Preferably the recessed heat sink is provided in the form of a cone which also functions as a reflector. The cone accentuates the lit 9 effects of the tri-coloured LED and minimizes glare at higher outputs. Still more preferably the emergency lighting and wayfinding indicator lighting components are provided in a single encapsulated epoxy or silicon dome shaped lens/casing. Even more preferably the unit complies with mandated 5 emergency lighting as per AS 2293.1 2005. The various standards are outlined in the appendix. This new type of emergency lighting unit combines the important functions of emergency lighting, wayfinding and safety way guidance. 0 In its most preferable form the invention achieves these multiple functions using a unique emergency lighting unit design, in which the reflector and heat sink are consolidated into a 'one piece' mechanical design and coupled to a fully recessed low-glare vandal proof tri-coloured LED module. The tri 5 coloured LED module encapsulates up to 3 coloured LED's specifically designed to provide visual ceiling mounted safety way guidance, wayfinding plus the mandated emergency lighting. Each LED can be individually controlled. o The design provides evacuees conspicuous, unambiguous visual cues along an escape paths, in additional to an emergency lighting mode in cases of power failure or disconnection. In its most preferred form the invention provides four different modes which 5 are: 1. Non- Emergency mode (mains power on working normally) for daily and training use. This means that the lighting unit is permanently lit green passive (non flashing) low luminous intensity providing directional indicators along emergency escape path(s) to Fire Exits, Refuges, etc. For example the green LED in the passive mode would draw a current of less than 50mA. 30 2. Emergency Evacuation mode (mains power on working normally) activated by a signal from building's fire control panel and remaining operational until mains power fails or is disconnected. This mode comprises flashing lit green (flashing @1 second intervals) high luminous intensity 35 directional indicators along emergency escape path(s) to Fire Exits, Refuges, etc. This flashing rate is similar to that prescribed for transport warning signals in Australia. Note: Mains power on implies that normal lighting would be on. This mode would draw a current of less than 300mA. 10 3. Emergency Lighting mode (mains power failed etc,) on failure or disconnection of mains power the unit will switch to internal UPS/battery to supply emergency lighting. This emergency lighting can be in white light or a more suitable colour to further delineate escape paths, from non-escape 5 paths during an emergency. For example the emergency white LED in this mode would draw upto 350mA. 4. Unit Failure. Occurs when the mains power is on and there is a catastrophic failure of charger. This is indicted by no normal operation green o signal present. Part of the motivation for inception of the present invention is that lighting standards have excluded consideration of the visual hazards presented by progressively forming fire smokes until very recently and 5 lack of coordination between audible and visual alarms and in the evacuation processes so important in making people aware of the need to react soonest and then assisting them to find an escape path(s) to the nearest fire exit or internal refuge. o Details of the research on smoke are given in the appendix. The publication of International Commission Illumination standard, CIE S 020/E: 2007 is the first emergency lighting standard to make recommendations seeking to improve the performance 'exit signage in smoke' by increasing luminance above10 cd/m 2 and lowering installed height of signs where possible. Currently 5 Australian standard mandates minimum of 8 cd/m 2 and does not allow signs to be mounted below 2 meters. In Australia the smoke hazard continues to be excluded in our emergency lighting standards and as a consequence emergency lighting sold in Australia 30 (both exits and complementary emergency luminaires) are designed and tested to work in clear air i.e. non smoke conditions. The sole function of emergency luminaires remains the illumination of escape paths when the power fails or is disconnected, normally by fire and rescue staff attending the forced evacuation. It is not designed to provide directional cues. 35 The standard has excluded fire smoke considerations and safety way guidance systems since its inception in late 1970's. At that time standards committee stated that their smoke exclusion was based on the view "there 11 was no practical way ensuring a system (the prescribed emergency lighting) would continue to be effective under smoke conditions". Mr I Wilson evaluated the effectiveness of Exit signs in smoke in relation to 5 the AS/NZS 2293 1979 standard amendments and in his conclusion noted "the performance of exit signs and emergency lighting systems in smoke warrants further study particularly since in the worst case smoke is likely to be present in at least part of the escape route when the evacuation of the building is required" (Wilson report 1990 page16). 0 The most recent edition of AS 2293.1 2005 Scope notes "due to the known detrimental effect of smoke on the visual conditions provided by emergency lighting it is recommended that provision be made to keep escape paths as free from smoke as possible by means such as constructional techniques and 5 ventilation". Importantly AS 2293.1 05 Clause 6.8.1 requires escape signage to be installed "not less than 2 meters and not more than 2.7 meters above floor level". Typically signs are mounted above doors or on or close to ceiling o heights i.e. 2.3 to 2.7 meters. This requirement last places signage in progressively forming smoke layers during a fire. The natural buoyancy of hot fire smokes means it will rise, forming layers until restricted by the ceiling or structure. Smoke control systems can accentuate 5 this layering effect and may increase smoke density above 2 meters level in complying with BCA E2.2b. Relatively thin and survivable fire smokes will quickly obscure low luminance backlit escape signage by forming a veil between the eye and the sign. 30 Signage will not be 'clearly visible at all times' at the designated viewing distances of 16, 24 or 32 meters for 100,150 or 200mm sign height pictorial elements respectively. The peak international lighting body CIE addressed this issue in a new 35 standard CIE S 020/E: 2007 stating in the Introduction "the primary objective of emergency lighting is the provision of visual conditions that can alleviate panic and facilitate safer evacuation of building occupants during the failure of normal lighting, in clear air (non-smoke) and smoke filled conditions". 12 Section 11 this standard states "generally smoke accumulates at the ceiling where it can obscure high mounted safety signs and we recommend the use of safety way guidance in accordance with ISO1 6069, increased luminance of exit signs to improve visual conspicuity and lower mounting of exit signs". 5 Smoke spreads much faster and further than fire growth. Many building occupants are hesitant to transit through even light smoke and so can become trapped in the early stages of a fire when smoke is survivable. Toxic hazmat, cyclones and other life threatening events mean people need to o escape the building or to the safety of an internal refuge quickly. AS 3745-2002 Emergency Control Procedures recommends emergency responses for workplaces which form the basis of most evacuation training. States regulations generally require the managing entity of multi-occupancy 5 buildings to produce and keep on site their Fire & evacuation plan. Today buildings detection and audible alarm systems cater for these events as well as fire but do not provide visual safety way guidance to speed transits to the nearest fire exit or refuge. This invention addresses this missing link in o building evacuation plan, by providing visual safety way guidance to complement the audible alarm systems and ameliorates some of the serious and known performance concerns of emergency lighting as prescribed in AS 2293.1 2005. 5 Learning the escape paths before an emergency is vitally important to safety.. .the 'Non-Emergency Mode' of this invention can be used to complement the buildings evacuation training plan, 6 monthly fire drills as recommended in AS 3745-2002. 3o Non-Emergency mode provides tractable low intensity and glare overhead green LED lighting along escape paths to fire exits or to refuges that building occupants can follow and learn on a daily basis. This is particularly important for new employees or those unfamiliar with a building layout or part of a larger building i.e. tenancies. 35 Warning and initiating early movement are recognized as a major safety factors for all forced evacuations. 13 Whilst mains power is on the 'Emergency Evacuation Mode' of this invention can be activated from a buildings fire alarm panel giving occupant's a high intensity flashing visual alerting and tractable safety way guidance to follow along escape paths to complement audible warning and annunciations. The 5 continuous flashing chain of high intensity green LED's (Cohn 1978) will be more conspicuous in a person's peripheral vision and actively encourage early movement to safety. When mains power fails (including power outages) or is disconnected the o luminaire's UPS backed emergency lighting will be activated as required by BCA/AS 2293.1 2005 Applications of the invention include: 5 1. Higher Risk Buildings. This invention will assist in alleviating these important safety issues with recommended installation along escape paths and at changes in escape path direction or as determined by fire safety engineer/authority i.e. retirement homes, hospitals, schools, hotels, large offices, shopping centre's, dangerous o or inflammable materials use, where occupants may be infirmed or asleep or unfamiliar or need structured or assisted evacuations. 2. Lower Risk Buildings. As above but recommended for single storey retail, restaurants, offices and 5 the like where total distance to fire exit exceeds meters 12 meters. 3. All Buildings. The invention will also provide the mandated emergency lighting as per BCA/AS 2293.1 2005 requirements in accordance with the BCA building 30 classifications on type/usage along escape paths. The current Australian emergency lighting minimum is 0.2Lx on floor, which between 5 and 50 times lower the international best practices of upto 1OLx. It should be noted that the present invention is not intended to replace escape 35 signage but complement it. In one of its preferred aspects the present invention provides far better emergency illumination. Specifically the 0.2Lx level is considered to be unsatisfactory for today's built environment. It is likely to be increased to along 14 escape path(s). The invention in a preferred form provides higher emergency lighting Lx level than mandated in Australia in keeping with best international practice. 5 In another preferred aspect of the invention comprises the lighting unit substantially as described in the illustrative embodiments, to a method of manufacture of the lighting unit of the invention and to a method of fitting out a building with a plurality of lighting units of the invention. 0 Detailed Description of Illustrative Embodiments of the Invention Possible and preferred features of the present invention will now be described with particular reference to the accompanying drawings, however it is to be understood that the features illustrated in and describe with reference to the 5 drawings are not to be construed as limiting on the scope of invention. In drawings: Figure 1 is a side sectional view of the lighting unit including the LED light source. The other components common to all emergency lighting luminaires o are not shown. Figure 2 is a side sectional view of the cap comprising the combined reflector and heat sink of the lighting unit. 5 Figure 3A is a plan view of the base of the lighting unit. Figure 3B is a sectional A-A of the base shown in figure 3A. Figure 4 is exploded above and underneath views (partly sectioned) of the 30 lighting unit. Referring to figures, lighting unit 1 comprises housing in the form of mounting base 10, cap 20, LED unit 30 and locking ring 40. The emergency lighting component and wayfinding indicator lighting component is provided by LED 35 unit 30 which is held in place between base 10 and cap 20. The lighting unit of the invention can be screwed into a standard single or double tubed 18w, 36w or 58w fluorescent ceiling fitting or ceiling troffer in 15 common use. As such the lighting unit may be factory fitted or retro-fitted, with a luminaire's other components (inverter, charger, battery pack and control gear) fixed inside the ceiling fitting or troffer and powered from the fittings power source. It is a common practice within the lighting industry worldwide to 5 convert non-emergency light fittings into emergency fittings. Similarly the unique lighting unit and tri- coloured LED light source can be screwed on a standard suspended ceiling spring fixing again in common use for wide variety of down lights for both domestic and commercial use. These o are not shown but consist of a ceiling mounting plate and two sprung clips which secure lighting units to underside of a ceiling tile. Suitably dimensioned base 10 of lighting unit 1 has a first end 10a and opposite thereto a second end 1Ob, a cylindrical portion 1Oc for receiving LED 5 unit 30 which sits on floor 10e of solid portion 10d. Bores 13 in solid portion 1Od are suitable for running electrical wires 15 from second end 1Ob to cylindrical portion 1 Oc. Solid portion 1 Od also has annular fins 11 on an outer surface to assist with heat dissipation. Cylindrical portion 10c has an internal thread suitable to receive cap 20 and an external thread suitable for receiving o locking ring 40 as described below. Suitably dimensioned cap 20 has a first side 20a and opposite thereto is second side 20b. Between first side 20a and second side 20b is first shoulder 20c, annular threaded portion 20d, second shoulder 20e suitable for retaining 5 an insulating washer as described below and beveled portion 20f. Cap 20 also comprises a cone shaped recess 25 which is defined by a surface extending between first circular opening 21 on first side 20a and second circular opening 23 on second side 20b at the other end. First circular opening 21 is larger in diameter than second circular opening 23. Cone shaped recess 25 is made of 3o appropriate material such as aluminum and functions both as a heat sink and reflector. Locking ring 40 comprises an internally threaded ring of suitable diameter to screw up over the external thread of cylindrical portion 1 Oc and abut first 35 shoulder 20c of cap 20. LED unit 30 comprises mounting disc 31, radialy disposed rebates 32 to accommodate wires 15, wiring terminals 33 and tri-coloured LED domed shaped lens/casing 36 and housing white, green and red LEDs. Tri-coloured 16 LED lens/casing 36 is made of epoxy resin or silicon. Domed shaped lens/casing 36 as shown encapsulates up to 3 separately controllable coloured LED's for emergency lighting, wayfinding indicator and directional safety way guidance as described. Preferably the first colour of which is white 5 and the second colour is green. When the components are assembled wires 15 are inserted through bores 13 and soldered to LED unit 30 which is placed inside base 10 on floor 10e. Insulating washer in the form of 0 ring 14 is seated on top of mounting disc 31 o and cap 20 is screwed into cylindrical portion 10c of base 10. 0 ring 14 prevents electrical contact between wires 15 and cap 20. Epoxy dome 36 extends through the second circular opening 23. Cone shaped recess 25 performs an important function in that the recess reduces glare and problems associated with a point of light temporary blinding effects associated with high 5 brightness LED's. Lighting unit 1 may be wired into standard 18w, 36w or 58w ceiling fluorescent light fitting or troffer's mains power (not shown). It has rechargeable batteries or UPS for times of power failure or when the mains are disconnected. o Optionally the control gear has an open/closing relay connected to the fire alarm wiring/panel of the built environment. Preferably this is a 24 V connection. This optional feature enables the combined emergency lighting/wayfinding of the present invention to be activated by a signal from the fire panel and to operate in concert with the fire warning system of a built 5 environment as explained in more detail below. The units are positioned overhead on the ceiling of the built environment or incorporated into a ceiling light fitting as described previously such that the wayfinding indicative light in the form of a green light track the escape path(s) 30 of the buildings fire exit(s) or internal refuge's. The units are placed apart at an appropriate distance, preferably at 8m to12 m centers and may be used to replace existing emergency lighting units. The constant illumination of the wayfinding indicators on the series of lighting 35 units means that the person using the building has an opportunity to learn the escape path(s) prior to an emergency. The invention is partly predicated on the recognition by the inventors that consciously or unconsciously humans, upon entering a building become spatially aware of their surroundings but not to the extent of recognizing escape path(s). Thus in an emergency people 17 attempt to exit the same way as they have entered a building which is generally not the nearest fire exit and not a designated escape path. The less familiar people are with the building or in a power outage/low light or in progressively forming fire smokes or combination of these hazards the greater 5 the risk of delays, confusion/panic and injury occurring. Independent testing clearly demonstrates the need for improved visual wayfinding techniques as proposed by this invention to be coordinated with audible fire alarm warnings. In a preferred aspect the lighting units are used in a multi-storey building o operating concert with the cascading response of a fire alarm system. For example in a multi-storey building if a fire is detected on the 14th floor the fire panel activates alarms on this floor and the floors directly above and below. If the fire is subsequently detected on adjacent floors the alarms cascade up and down respectively. In a preferred aspect the lighting units of the system 5 and methods of the invention are integrated with this cascading system such that in emergency conditions the wayfinding lights begin flashing and operate to warn people and start the evacuation process. This is optionally achieved by flashing on/off and increasing intensity of the second color. o Preferably the system and methods of the invention meet the building code requirements of the country where they are installed. Whilst wayfinding is not mandated by the codes they provide for it as an option. For example BCA at EP4.2 provides for "other means of identification must to the degree necessary - (a) be provided to identify the location of exits; and (b) guide 5 occupants to exits and, (c) be clearly visible; and (d) operate in the event of a power failure of the main lighting system for sufficient time for occupants to safely evacuate ". Further preferably the various aspects of the invention meet the BCA requirements to provide, in combination with existing exit signage, adequate lighting in an emergency, have adequate identification of exits and 30 paths to exit, make occupants aware of an emergency, warn occupants to evacuate, manage the evacuation process including identification of exits and paths to travel to an exit. Preferably the invention is also suitable in assisting visually impaired people 35 by providing intermediate wayfinding (flashing green coupled with audible alarms) down an escape path(s) exit signage is not clearly visible at 24 meter distance's. In a preferred aspect the invention provides a visibly trackable continuous line of sight along the escape path(s). As described in the smoke research outlined in the appendix a building occupant will not be able to see a 18 sign at 16, 24 or 32 meters in thin to moderate fire smoke. Eye irritation effects slow transit speeds by up to two thirds in effect making a 50 meter escape path 150 meters long and increasing the health and injury risks. For the less familiar, vision or movement impaired occupants, these risks are 5 greatly increased. The longer a person is exposed the greater the disorientation, panic and increased prospect of injury occurring. Furthermore by the use of LED of the present invention provides a distinct advantage because tests on safety signs show that in smoky condition's LEDs o are most visible in moderate and dense smoke whereas photoluminescent, photoluminescent luminaire combinations and reflective pictograms and luminaire combinations are least visible in smoke. Throughout this specification and the claims that follow, unless the context 5 requires otherwise the words "comprise", "comprises", "comprising" will be understood to mean the inclusion of the stated integer, step or group of integers or steps but not the exclusion of any of other integer, step or group of integers or steps. o Appendix Explaining Relevant Standards and Research The Building Code of Australia (BCA) prescribes AS 2293.1 2005 which provides the regulatory framework for both States and Federal agencies legal and administrative processes e.g. Queensland Building Fire Safety Regulation 5 2008. Emergency Lighting is prescribed in part E4 of BCA 2006 volume one and describes the objective in section E04 "to safeguard occupants from injury in an emergency by having adequate lighting, identification of exits and paths of 30 travel to exits and being made aware of an emergency". BCA part EF4.1 functional statement clarifies this further stating "adequate lighting is to be provided upon failure of artificial lighting during an emergency and adequate means is to be provided to warn occupants to evacuate, 35 manage this process, and identify exits and paths of travel to an exit". BCA part EP4.2 performance requires suitable signs or other means of identification must "guide occupants to exits, identify the location of exits, be 19 clearly visible to occupants, operate in event of power failure for safe evacuation" BCA part E4.8 design requires exit signs "be clearly visible at all times when a 5 building is legally occupied". BCA specification E2.2b requires smoke control fans to maintain tenable conditions for not less than 2 meters above floor level for specific periods and building types. 0 AS 2293.1 standard gives a set of 'minimum requirements' for the design of emergency lighting luminaire's and includes factors such as luminaire construction, installation and maintenance, compliance testing and classification of luminaire's. 5 Mandatory Requirements. Compliance and Inspection with BCA is normally undertaken by State Fire Brigades and/or Local Authorities under their jurisdictions. These regulators are able to approve alternative or engineered solutions to the BCA's deemed to satisfy standards relating to evacuation e.g. o use of lifts, paths of travel, smoke control, signage, smoke control, etc. AS 2293.1 standard gives a set of 'minimum requirements' for the design of emergency lighting luminaire's and includes factors such as luminaire construction, installation and maintenance, compliance testing and 5 classification of luminaire's. Fire Smoke Research. 3o Tests by various international expert authorities in North America, UK/EU and Japan acknowledge the serious threat posed by fire smoke on visual conspiciuty and the potential high risks it poses to all building occupants. Below follows a summary of this science based commentary. 35 The UK Building Research Establishment (BRE) published research papers 1994 IP 17/94 titled Emergency Wayfinding Lighting systems demonstrated that recognition distance for a typical backlit exit signage (similar to those prescribed in AS2293.1) would be reduced from approximately 24 to 6 meters, in light to moderate smoke densities of 0.4 m-1. (See BRE graph). 20 BRE findings generally concur with work of Dr T Jin National Fire Protection Equipment & Safety Centre of Japan, who showed that in moderate smoke densities between 0.4 and 0.7 m-1 visibility would be reduced to approx 5 5 meters. Jin & Yamada (1985) further evaluated irritant effects of fire smokes on occupant's (eyes and breathing) and thus transit speeds. They observed that transit speeds reduced from approx 1.2 to 0.4 meters per second as density o increased to moderate level of 0.7m-1. This would substantially increase transit times and exposure to fire smoke. The Norwegian Fire Research Laboratory carried a series of tests using Exit signage and found that up to 40% of test subjects could not find the fire exit in 5 smoke and less than 10% noticed signs when fleeing from a fire. (Professor Withington 2007 Sydney International Lighting Conference) Cohn (1978) evaluated evacuation egress conditions and reported that yellow light was most effective for visual conspiciuty followed by green and red. 0 Demaree of the US Federal Aviation Admin (FAA) classified smoke densities from his tests in optical density terms m-1 as follows: Light.......... < 0.35 5 Moderate.... < 0.35 to 1.17 Dense.........< 1.17 to 3.50 Very Dense < over 3.50. Sime (1984/5) analyzed escape route egress data to found that people tended 30 to select a route they were most familiar with or the way they came in during an emergency, even though that it may not lead to an fire exit or route to a fire exit. He concluded that 2.5 minutes would not allow sufficient time to initiate movement if information to evacuees was insufficient. 35 US National Institute of Standards & Technology NISTIR tests demonstrated that signs viewed from 20 meters with mean illuminance below 12cd/m2 disappeared in very thin smoke with midpoint optical densities of 0.1 od/m-1 in less than 5 minutes; whilst signs above 12 lasted only twice as long. 21 AS 2293.1 requires signs to have minimum illuminance of 8 cd/m2. References 5 Withington D "Light plus sound = Safescape" presentation, School of biomedical science, University of Leeds, Leeds UK. Webber GMB and Shipp MP "Review of emergency lighting and way o guidance systems for offshore structures." HSE Offshore Technology Report OTH 95 499. HSE (HSE Books). Jin T and Yameda T "Irritating effects of fire smoke on visibility". Fire Science and Technology 5 79-90 1985. 5 Jin T" Visibility through fire smoke, Part 5: allowable smoke density for escape from fire". Report of the Fire Research Institute of Japan, 43 12-14 1976. Webber GMB and Aizelwood CE "Emergency wayfinding lighting systems in o smoke" Building Research Establishment Information Paper IPI 17/94 BRE Garston 1994. British Standard BS5226 Part1 "Code of practice for the emergency lighting of premises used for entertainment" BSI London 1988. 5 Webber GMB and Aizelwood CE "Emergency wayfinding lighting systems in smoke" Proceedings of the CIBSE National Lighting Conference Cambridge March 1994 131-143 1994. 30 Wilson I "The effectiveness of exit signs in smoke" Lighting in Australia 10(1) 14-19 1990. Collins BL Dahir MS and Madrzykowski D NISTIR 4399 "Evaluation of exit signs in clear and smoke conditions" NIST USA 1990. 35 Jin T "Visibility through fire smoke" Journal of Fire and Flammability 9 (April) 135-155 1978. 22 Jin T and Yameda T "Experimental study of human behavior in smoke filled corridors" Fire Safety Science-Proceedings of the Second International Symposium, Tokyo, June 1988 Hemisphere Publishing Corporation New York 5 511-519 1989. Australian Standards Association Emergency Evacuation Lighting in Buildings AS 2293 part 2007. o Cohn BM "Study of human engineering considerations in emergency exiting from secure places". Gage Babcock and Associates Inc Report #7762.2 March 1978. Rea MS Ouellette MJ and Clark FRS "Design considerations for egress signs 5 based on visibility through smoke" Proceedings of American Institute of Architecture Conference on Research and Design Los Angeles 295-277 1985. Sime JD " Movement towards the familiar: person and place affiliations in a fire entrapment setting" in Duerk D and Campbell D (Eds) The Challenge of o Diversity: Proceedings of EDRA/15 Washington DC EDRA 100-109 1984. Sime JD "Perceived Time Available: The Margin of Safety in Fires" School of Architecture Portsmouth Polytechnic. 23