Lamps Chapter 5 © 2006 Fairchild Publications, Inc.

Families Incandescent Tungsten-halogen Discharge Fluorescent, cold cathode, neon HID (High-Intensity Discharge) LED (Light-emitting diode) Chapter 3 Electrical Sources © 2006 Fairchild Publications, Inc.

Lamps

Characteristics Light output Efficacy Color Lamp life Maintenance factors Cost Chapter 3 Electrical Sources © 2006 Fairchild Publications, Inc.

Comparative lamp efficacy

Lamp life

Consider heat load on building too…

Naming Wattage + Bulb shape + Bulb size [+other information]

Incandescent Lamps Operating principles: Electrical current heats tungsten filament until incandescence Heat causes filament to thin and break Fragments of tungsten deposit on glass Bulb made of blown soda lime (soft) glass Inert gases added to bulb to reduce oxidization of tungsten filament

Standard shapes

Three-way lamps Two filaments: One filament for lowest wattage (50) Second filament produces next highest wattage (100) Two filaments operating together produce highest illumination wattage level (150) Chapter 3 Electrical Sources © 2006 Fairchild Publications, Inc.

Fun facts 10–15% of energy produces light Dimming reduces amount of light and heat Operating voltage affect life Any mounting position Chapter 3 Electrical Sources © 2006 Fairchild Publications, Inc.

Advantages Greatest amount of flexibility Directional or non-directional illumination Varied size and shape Easy dimming Quick on Frequent starts High optical control Low initial cost Excellent CRI Chapter 3 Electrical Sources © 2006 Fairchild Publications, Inc.

Disadvantages Low efficacy rating Generation of heat Relatively short life Damages artwork, fabrics, and other precious materials Chapter 3 Electrical Sources © 2006 Fairchild Publications, Inc.

Options Frosted lamps: Acid etch Soft-white: Coated with silica Crown-silvered lamps: Coating covering top half Rough service Protective shielding Chapter 3 Electrical Sources © 2006 Fairchild Publications, Inc.

Reflector incandescent Reflector (R) lamp: Improves efficacy and directional qualities Halogen parabolic aluminized reflector (PAR) Elliptical reflector (ER) Multifaceted reflector (MR) Chapter 3 Electrical Sources © 2006 Fairchild Publications, Inc.

Beam spread ranges Spot to flood Codes: Example: SP, NS, VNSP, WFL, MWFL, VWFL Example: SP10: a spot lamp with a 10% beam distribution Chapter 3 Electrical Sources © 2006 Fairchild Publications, Inc.

Reflector (R) and Parabolic Aluminized Reflector (PAR) Lamps

Tungsten-Halogen Lamps Halogen regenerative cycle: Evaporated tungsten redeposit on the filament Requires a heat-resistant glass (quartz) ~ 20-30% more efficient than incandescent Longer life Whiter light Higher color temperature and efficacy rating MR 16, MR11 MR8, and PAR popular Chapter 3 Electrical Sources © 2006 Fairchild Publications, Inc.

Tungsten-Halogen Lamps Line voltage Low-voltage with a transformer: Device to step down electrical current Chapter 3 Electrical Sources © 2006 Fairchild Publications, Inc.

The halogen effect

Different lamps come with different bases: can help (or hurt) inventory control

Halogen incandescent lamps shapes and their designations

Fluorescent Lamps Electrical current passes through hot tungsten cathodes at end of tube Tube with low-pressure mercury vapor gas and other inert gases Cathodes emit electrons that excite mercury gas Vaporized mercury produces radiant energy Phosphorous coating determines color of the light Chapter 3 Electrical Sources © 2006 Fairchild Publications, Inc.

Lamp shapes and sizes T12, T8, and T5 Decoding catalog #: F48T8CW Fluorescent (F) lamp 48 watts (48) Tubular shape (T) 8/8” in diameter (8) Cool-white color (CW) Inch mark = Tahoma font Chapter 3 Electrical Sources © 2006 Fairchild Publications, Inc.

Ballast construction Can effect efficacy of luminaire Generally considered hazardous waste

Advantages Energy efficient High lumen output Long life Radiate less heat than incandescent Moderate initial cost Low operating cost Variety of color options Use up to 80% less energy than incandescent Can last up to 18 times longer than incandescent

Disadvantages Needs ballast Flickering can occur Indoor use only Time needed to reach maximum lumen output Sensitive to ambient temperatures Dimming is expensive Shape and size limitations Mismatches with lamps and ballasts Variations between lamp manufacturers Continuous on and off is detrimental to life and performance of lamp

Compact Fluorescent Lamp (CFL) 1 or 2 linear fluorescent tubes are folded, bent, or twisted Twin, triple, and quad tubes Ballast: Separate control gear or Built into the unit (integral system) Chapter 3 Electrical Sources © 2006 Fairchild Publications, Inc.

Advantages Disadvantages Replacement for incandescent Crummy replacement for incandescent CRI, color temp, warm-up time

High-Intensity Discharge (HID)

HID Functions Similar to fluorescent lamp: Illumination begins with arc between 2 electrodes Operates in a gas-filled cylindrical tube Requires ballasts Creates radiant energy from gases and metal vapors Doesn’t use phosphors to generate light in visible range Chapter 3 Electrical Sources © 2006 Fairchild Publications, Inc.

Metal Halide Lamp shapes

Restrike time

Advantages – HID Lamps HID characteristics: MH gives decent CRI, color temp. Very good optical control Very high efficacy Very long life Operation in a wide range of ambient temperatures Positive long-term economics Chapter 3 Electrical Sources © 2006 Fairchild Publications, Inc.

Disadvantages – HID Lamps Long start-up time (up to 5 min.) Long re-start time (up to 15 min.) Color shifts during the life of lamp Variations in color between the same lamps Strict ballast requirements Not easily dimmable Chapter 3 Electrical Sources © 2006 Fairchild Publications, Inc.

LED lamps

Operation Not called “lamps”

Electrons jump across gap between “N” and “P” metal plates

Designated driver Constant voltage type Constant current type Can add more (parallel circuit) Typical of string lights Constant current type Total voltage for entire circuit Requires more precise planning More efficient Better dimming

Advantages of LED Can be made in almost any incandescent bulb shape Can be made in almost any fluorescent bulb shape Very long life (20,000-100,000 hours) Very high efficacy (20-100 lumens/W) Dimmable

Disadvantages of LED Very high initial cost Heat dissipation concerns CRIs typically only in the 80’s

Light source selection criteria

Other more rare types… OLEDs Cold Cathode and Neon Fiber optics Planar source Cold Cathode and Neon Both have very long life, decorative applications Fiber optics Usually uses Metal Halide as source

In-class exercise Sketch RCP of assigned room Count lamps in each luminaire Guess wattage Fluorescents are probably 32W Incandescent downlights are 100W Metal Halides are 150W Total up (make a little chart) Find price in lightbulbs.com Calculate total cost of lamps Chapter 3 Electrical Sources © 2006 Fairchild Publications, Inc.

Groups of two VPAC 204 and 205 VPAC Main gallery The Lodge Academic Center SW lobby and corridor Academic Center café Science Building main lobby