Presentation on theme: "CRIME PREVENTION THROUGH ENVIRONMENTAL DESIGN Security Lighting."— Presentation transcript:
CRIME PREVENTION THROUGH ENVIRONMENTAL DESIGN Security Lighting
Alan D. Duer, CPP Security Analyzer Baltimore Gas and Electric Company 7309 Windsor Mill Road Baltimore, MD phone fax e mail
CPTED 90 % of crime occurs after dark Proper lighting enables law abiding citizens to observe / report crime and to identify suspects. It makes people feel safe.
Lighting Terminology Light: Radiant energy that excites the retina of the eye. Lumen: Volume of light Candlepower: Intensity of light in a specific location. Foot Candle: amount of light a candle gives off in a square foot area. Illuminance: Light on an object
Lighting Terminology Lux: metric measurement of illumination Lumen: measurement of light at its source and the amount of light output. Luminaire:The complete light fixture with the light source and ballast. Light trespass:Light pollution in unintended areas. HID: High Intensity Discharge Lamp
Lighting Terminology LPW: Lumens per watt, a measurement of efficiency Ballast: A device used with an electric discharge lamp to obtain the necessary voltage and current to start and operate the lamp. Uniformity: Relative Illuminance, lighting that doesnt allow dark areas in parking lots.
Fluorescent Lamps that pass electricity through a gas enclosed tube to create light Usually used indoors and in some cases for signage
Fluorescent Advantages: 1) They create twice the light & less than half the heat of an incandescent bulb of equal wattage. 2) Long life (10, ,000 hrs.) 3) Efficient 4) Good color rendition
Fluorescent Disadvantages: 1) Temperature sensitive
Mercury Vapor A high intensity discharge device which produces light by excitation of mercury vapors (also passes electricity through a gas) Emits a bluish white light
Mercury Vapor Advantages: 1) Long life ( ,000 hrs.) 2) Low initial cost
Mercury Vapor Disadvantages: 1) Inefficient operation 2) Light output drops over life (2 - 3 yrs.) 3) Delayed hot restart
Metal Halide High intensity discharge arc tube in which light is produced by the radiation of exited metal halides 100 watt bulb lasts 10,000 hrs.
Metal Halide Advantages: 1) Excellent color rendition 2) Sparkling white light a) imitates daylight conditions b) used in sports stadiums, car dealer lots, etc. 3) Works well with CCTV
Metal Halide Disadvantages: 1) Hot restart can take several minutes 2) High initial cost 3) Most expensive light to install and maintain
High Pressure Sodium High intensity discharge arc tube in which light is produced by radiation from sodium vapor operating under pressure
High Pressure Sodium Advantages: 1) Very Efficient ,000 hrs. life 2) Can cut through fog and allow the eyes to see detail at greater distance ( used on streets & parking lots ) 3) In some cases it can be used with CCTV
High Pressure Sodium Disadvantages: 1) High initial cost of fixtures 2) Hot restart can take several minutes
Low Pressure Sodium High intensity discharge arc tube in which light is produced by radiation from sodium vapor operating under pressure Emits a dull yellow /gold hew
Low Pressure Sodium Advantages: 1) Very efficient ( ,000 hrs. life, a 90 watt bulb may last 16,000 hrs.) 2) May be used to combat prostitution, drug dealing, or illuminate an area just to detect movement.
Low Pressure Sodium Disadvantage: 1) Poorest color rendition
Security Lighting Recommendations 1) Illuminate entrances, fire escapes, etc. with bright white light. 2) Parking lots should be illuminated with bright white lights that allows for uniformity, (not allowing any dark areas in the parking lot). 3) Implement a maintenance policy
Security Lighting Recommendations 4) Parking lots should be illuminated so one can identify a human face at 33 ft.,(3 foot candles vertically above the surface). 5) Wire cages or industrial strength shatter resistant lenses should be placed over the light to deter vandalism. 6) Position lights to avoid glare areas & blind spots.
Parking Lot Illumination The general rule of thumb involving the installation of lighting in parking lots, is the height of the light pole multiplied by 4 will give the distance the light poles should be apart.
Building Illumination The general rule of thumb involving the installation of wall packs, (lights on the sides of a building), is the height of the wall pack multiplied by 6 will give the distance the wall packs should be apart.
Lighting Benefits 1) Less vandalism 2) Fewer Break-ins 3) Improved morale & safety / security 4) Fewer assaults 5) Premise liability enhanced 6) Increased curbside appeal 7) Increased building value 8) Improved Productivity 9) Increased utilization of public areas resulting in more natural surveillance
National Institute of Justice Research in Brief - April 1996 The most important CPTED security feature is lighting. Lighting should meet standards of the Illuminating Engineering Society of North America. The most important CPTED security feature a city can mandate is lighting.