Energy Efficient Lighting Design Concepts For Your Home

key_points
  • Energy efficient lighting can reduce energy use by 50%–75%.
  • Fluorescent lamps use 65%–75% less energy than incandescent bulbs.
  • The use of timers, photo sensors, and motion sensors help to conserve energy.

Energy-efficient lighting design focuses on methods and materials that improve the quality and efficiency of lighting. Installing task lighting where needed, using energy-efficient lighting components, controls and systems, and maximizing the use of daylighting all help to reduce energy use.

Interior Lighting Options

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  • Interior Lighting Options Incandescent bulbs produce a warm light; use 10 to 17 lumens per watt, with an average operating life of 750 to 2500 hours.
  • Tungsten halogen lamps provide excellent color rendition. Reflector (R) and parabolic aluminized reflector (PAR) lamps are slightly more efficient than standard bulbs, with average operating life of 2000 to 4000 hours, and are excellent for accent lighting.
  • Fluorescent lamps use 65%–75% less energy than incandescent bulbs to provide the same amount of light (30 to 110 lumens per watt), with an average operating life of 7,000 to 24,000 hours-almost ten times longer. Fluorescent lamps with electronic ballasts outperform standard and improved electromagnetic ballasts by operating at a very high frequency that also eliminates flicker and noise. Tube-type fluorescents (T12s or T8s), require special fixtures with built-in ballasts, but the newer, compact fluorescent lamps (CFLs) are often sold with built-in (or separate) electronic ballasts and adapters which can be used in fixtures designed for incandescent bulbs. Fixtures designed for use with plug-in (pin) type CFLs are also available with electronic ballasts.
  • Today’s highly efficient windows make it easier than ever to use windows and skylights to bring light into the home during the day without causing heating or cooling problems. South-facing windows are most advantageous for daylighting because they bring the most sunlight into the home during the winter, but little direct sun during the summer, especially when properly shaded.

Efficacy (lumens/watt)

Lifetime (hours)

Color rendition index (CRI)*

Color temperature (K)**

Incandescent
Standard "A" bulb

10-17

750-2500

87-100 (Excellent)

2700-2800 (Warm)

Tungsten halogen

12-22

2000-4000

98-100 (Excellent)

2900-3200 (Warm to neutral)

Reflector (R)

12-19

2000-3000

98-100 (Excellent)

2800 (Warm)

Parabolic aluminized reflector (PAR)

12-19

2000-3000

98-100 (Excellent)

2800 (Warm)

Fluorescent
Straight tube

30-110

7000-24,000

50-90 (Fair to good)

2700-6500 (Warm to cold)

Compact fluorescent lamp (CFL)

50-70

10,000

65-88 (Good)

2700-6500 (Warm to cold)

Circuline

40-50

12,000

Outdoor Lighting
Mercury vapor

25-60

16,000-24,000

50 (Poor to fair)

3200-7000 (Warm to cold)

Metal halide

70-115

5000-20,000

70 (Fair)

3700 (Cold)

High-pressure sodium

50-140

16,000-24,000

25 (Poor)

2100 (Warm)

Low-pressure sodium

60-150

12,000-18,000

-44 (Very poor)

* CRI is a measure of how “true” or realistic the colors of objects beneath the light appear.
** Color Temperature is a measure of how “warm” or “cool” the light from a bulb appears.

Lighting Control Options

While the toggle switch is the most common lighting control used in homes, using dimmer switches, timers, or occupancy sensors can help save more energy.

  • Fluorescent dimmers-dedicated fixtures and bulbs-provide even greater energy savings than regular fluorescent bulbs.
  • Strategically located occupancy sensors will turn lights on automatically when someone enters the room, and turn them off soon after they leave. There are two types of occupancy sensors: ultrasonic sensors that detect sound, and infrared sensors that detect heat and motion.
  • Timers are a great option for keeping your home well-lit when you’re away, but most homeowners find timers inadequate when they are home.

Outdoor Lighting Options

Outdoor lighting can be used to illuminate the exterior of the home and landscape, provide security, and to illuminate the steps, porch, and driveway so you, your family, and friends can move about safely after dark.

  • Incandescent lamps are the most common choice for outdoor lighting.
  • Fluorescent lamps do not operate well at temperatures below 40°F so they are generally not the best choice for outdoor use. Certain types of compact fluorescent lamps (CFLs), however, are specially designed to operate at temperatures as low as –20°F.
  • Mercury vapor lamps last for 16,000 to 24,000 hours on average, with an energy efficiency of 50 lumens per watt, and are suitable for many outdoor settings.
  • Metal halide lamps last for 16,000 to 24,000 hours on average, with an energy efficiency of 50 to 140 lumens per watt, and are suitable for outdoor settings.
  • High-pressure sodium lamps last 16,000 to 24,000 hours on average, with an energy efficiency of 50 to 140 lumens per watt.
  • Low-pressure sodium lights are the most efficient and last 12,000 to 18, 000 hours.