Home Maintenance Tips: Lighting Science!

Everything we know about lighting is changing faster faster. As of January 1, 2012, all light bulb packaging will be changing as we move from Watts to Lumens! Incescent bulbs will be unavailable in a couple of short years! As with other technologies, we have found ways to make LED light bulbbetter lights, with true colors, using far less energy save money over time. These lights are called LED’s, or Light Emitting Diodes. They have been around since 1962, traditionally used as indicator lamps in many devices increasingly used for other lighting. Early LEDs emitted low-intensity red light, but modern versions are available with very high brightness, or Lumens.

LEDs are often small, present many advantages over incescent light sources including lower energy consumption, longer lifetime, improved robustness, smaller size, faster switching. LEDs powerful enough for room lighting are relatively expensive, but as shown in the chart below, a very economical choice over time:

 Cost Comparison : LEDs, CFLs Incescent bulbs

Light bulb projected lifespan50,000 hours10,000 hours1,200 hours
Watts per bulb (equiv. 60 watts)61460
Cost per bulb$35.95$3.95$1.25
KWh of electricity used over3007003000
50,000 hours
Cost of electricity (@ 0.10per KWh)$30$70$300
Bulbs needed for 50k hours of use1542
Equivalent 50k hours bulb expense$35.95$19.75$52.50
Total cost for 50k hours$65.95$89.75 $352.50


Here are three new definitions you should learn before you purchase your next light bulb or light fixture. Keep in mind that in a couple of short years, you will no longer be able to purchase regular incescent bulbs, they are being completely phased out in the United States.

Lumena unit of stard measurement that is used to describe the amount of light contained in an area as perceived by the human eye. The more lumens, the brighter the light. Here’s the key, you can use lumens to compare the brightness of any bulb, regardless of the technology behind it, regardless of whether it’s incescent, CFL or LED.

Coloring Rendering Index (CRI) – CRI represents the quality of light its faithfulness to render colors correctly. The CREE CR6 bulb, for example, features a CRI of 90 Warm White making it one of the highest in the industry.

 Correlated Color Temperature (CCT)is the measure used to describe the relative color appearance of a white light source. CCT indicates whether a light source appears more yellow/gold/orange or more blue, in terms of the range of available shades of “white.” CCT is given in kelvins (unit of absolute temperature). 2700K is “Warm” 5000K is “Cool”. (Which seems the opposite of what it should be!)

This is the new vocabulary of lighting bulb manufacturers. When you go to the store, you will see something like this on the packaging, depending on the type:

Incescent WattsCFL WattsLED WattsLumens (Brightness)
40 8 to 124 to 5450
6013 to 186 to 8890
75 – 10018 to 229 to 131210
10023to 3016 – 201750
15030 – 5525 – 282780

It may take a little getting used to, but it’s better to know as much as possible about lighting your home, lscape, or business, especially when huge cost saving benefits over the lifespan of your lumens!

HB Building Design can light up your life with a new lighting design installation to prepare you for the future. We are lighting specialists! Call for a free quote 650-728-5878.