1 / 13

LAMPS (Chapter 3)

LAMPS (Chapter 3). Lamp efficacy, life, and color Incandescent Incandescence (Additional information) Light emitted from a heated object Uses a tungsten filament enclosed in a glass bulb, usually filled with a mixture of nitrogen and argon gases Operates at 4800 o F

cruz-harmon
Download Presentation

LAMPS (Chapter 3)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. LAMPS (Chapter 3) • Lamp efficacy, life, and color • Incandescent • Incandescence (Additional information) • Light emitted from a heated object • Uses a tungsten filament enclosed in a glass bulb, usually filled with a mixture of nitrogen and argon gases • Operates at 4800oF • Tungsten has the highest melting point of all metals (6170° F) and has a high conductivity • Efficacy (some additional information) • Efficacy = Lumens/Watt • Life • Color • Special lamps • Lamp Shape and size

  2. LAMPS (Chapter 3) • Fluorescent lamps • Fluorescence (Additional information) • Conversion of ultra-violet light into visible energy • Efficacy • Life • CRI • Color • Operation • Lamp types and bases • Preheat • Instant start • Rapid start • High and very high output • Lamp designations • Ballasts • Special fluorescent lamps • Compact • Energy efficient fluorescent lamps • Cold cathode • Neon

  3. LAMPS (Chapter 3) • High intensity discharge (HID) • What is it? • Production of light by passing an electric arc through a conductive vapor • HID efficacy and life • Mercury • Color • Efficacy • Life • Sodium • High pressure • Low pressure • Color • Efficacy • Life • Metal Halide • Color • Efficacy • Life • CRI • Comparisons • Other types • E-lamp • A compact high-tech induction reflector lamp • LED • Special semi-conductor chips (diodes) that emit light when connected in a circuit

  4. LIGHTING NUMBERS (Chapter 7) • Terms and accents • How much light? • Luminaire photometrics • Luminaire (Additional information) • Complete lighting unit consisting of lamps, parts that position and protect lamp, and means of connection to power supply. Also referred to as a fixture • S/MH (spacing-to-mounting height ratio [spacing between two adjacent luminaires/mounting height of the luminaire); also called spacing criteria (SC)] • Coefficient of utilization (CU) • CU values are influenced by (Additional information): • Room surface reflectances • Size and shape of a room • Location of luminaires • Design of luminaires • Light loss factor (LLF) (Additional information) • Ratio of illumination of a given area after a period of time to the initial illumination on the same area • Usually two main factor are taken into consideration for calculating LLF (additional information): • Lamp lumen depreciation (LLD): A factor used to account for reduced lumen output due to aging of lamp sources. • Luminaire dirt depreciation (LDD): A factor used to account for reduced illumination due accumulation of dirt on luminaires. May be obtained by consulting the Maintenance Category of the luminaires. • LLF = LLD*LDD • Cavity ratio (CR) (Additional information) • A number that indicates the proportions of a cavity (space) calculated from its length, width, and height. Room, floor, and ceiling cavity ratio have to be determined. • RCR • FCR • CCR

  5. LIGHTING NUMBERS (Chapter 7) • Footcandle calculations • Example calculations • Reflectances • Coefficient of utilization • CU values are influenced by (Additional information): • Room surface reflectances • Size and shape of a room • Location of luminaires • Design of luminaires • Lighting quality numbers • VCP • ESI • CRF • VDT

  6. L Perimeter = 2x(L+W) W

  7. LIGHTING DESIGN (Additional information) • Determination of CU • Divide the space into cavities: (1) Ceiling cavity (2) Room cavity (3) Floor cavity • Determine cavity ratio: CR = 2.5*cavity ht.*cavity perimeter/cavity area • Example: • Room cavity ratio = [2.5*5.5*(29.33+14+29.33+14)]/410.62 = 2.9 • Reflectances • Find out wall, ceiling, and floor reflectances based on surface colors • Find out effective ceiling and floor cavity reflectances • Effective ceiling cavity reflectance: Combined reflectance effect of all surface areas above plane of luminaire • Effective floor cavity reflectance: Combined reflectance effect of all surface areas below work plane • Use actual reflectances when CR = 0 • Adjust CU if effective floor cavity reflectance is more than 30% or less than 10%

  8. LIGHTING DESIGN (Additional information) • Choosing a luminaire • Choose one that has a CU table available • Use lamps with high efficacy • Determine number of lamps and find out initial lumens, life, and replacement protocol • Spacing criteria (SC or S/MH) • Fixture spacing should have an acceptable uniformity of illumination. Use recommended SC factor to determine both across (side-to-side) and along (end-to-end) spacing. • Formula to be used for lighting design • Illuminance = (No. of luminaires*lamps per luminaire*lumens per lamp*CU*LLF)/Area • No. of luminaires = (Illuminance*Area)/(Lamps per luminaire*lumens per lamp*CU*LLF)

More Related