Incandescent Lighting

Incandescent

Incandescent lighting

Incandescent lighting is the most common type of lighting found in homes.  It is also the least efficient.   Incandescent light bulbs convert only about 10% of the electricity they use into light.  The remaining 90% gets wasted as heat.  Though these bulbs are the least expensive to buy, they are often the most expensive to operate, with a low efficacy of 10-17 lumens per watt and a short average operating life (between 750 and 2,500 hours).  The three most common types of incandescent lamps are standard incandescent lamps, tungsten halogen lamps, and reflector lamps.

What are my options?

  • Standard Incandescent (“A” Bulb) Lamps:  This is the least efficient light source available.  Standard incandescent bulbs produce light from a coil of tungsten that glows when heated by an electrical current.  Larger wattage bulbs have a greater efficiency than smaller wattage bulbs, but they are not always the most energy-efficient or cost-effective option. “Long-life” bulbs last longer than standard A-type bulbs, but they are even less efficient.
  • Tungsten Halogen Lamps:  These lamps provide bright white light.  They are 10% more efficient than standard A-type bulbs, and they last three to four times longer.  Halogen incandescents generally cost between $10 and $20.
  • Reflector Lamps (Type R): These lamps spread and direct light over specific areas.  There are two types of reflector lamps, parabolic aluminized reflector lamps (Type PAR) and ellipsoidal reflector lamps (Type ER).  PAR lamps have a durable glass lens that helps focus the light.  Halogen PAR spotlights and floodlights use one-third less energy than standard reflector lamps, and halogen PAR infrared bulbs save even more energy.  ER lamps focus the light beam two inches ahead of the lamp and are twice as efficient as parabolic reflectors.
Lighting Type Efficacy (lumens/watt) Lifetime (hours) Color Rendition Index (CRI) Color Temperature (K) Indoors/
Outdoors
INCANDESCENT
Standard "A" Bulb 10-17 750-1000 98-1000 (excellent) 2700-2800 (warm) indoors
outdoors
Tungsten Halogen 12-22 2000-4000 98-1000 (excellent) 2900-3200 (warm to neutral) indoors
outdoors
Reflector 12-19 2000-3000 98-1000 (excellent) 2800 (warm) indoors
outdoors
FLOURESCENT
Straight Tube 30-110 7000-24,000 50-90 (fair to good) 2700-6500 (warm to cold) indoors
outdoors
Compact Flourescent Lamp (CFL) 50-70 10,000 65-88 (warm to cold) 2700-6500 (warm to cold indoors
outdoors
Circline 40-50 12,000     indoors

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