Madison Wisconsin best lighting

Light Bulbs 101

Now here’s a topic that used to be quite simple that lately has become almost overwhelming. Save energy and frustration with this brief tutorial on bulbs.

Residentially there are 3 major types of light bulbs; incandescent, fluorescent and LED.

Incandescent Bulbs

incandescent light bulbWe’ll start here because we’ve all bought them.  You may know the Energy Independence and Security Act (EISA) of 2007 sets performance standards for all light bulbs.  It does not ban incandescent bulbs; rather it sets minimum efficiency levels that have forced them to be re-designed, and so their packaging has been updated. If you’ve bought bulbs in the past couple of years you’ve seen the change. The deadlines and goals for the phased-in requirements are:

  • On January 1, 2012, light bulbs as bright as a 100 watt traditional incandescent bulb could use no more than 72 watts of electricity.
  • In January 2013, bulbs as bright as a current 75-watt incandescent could not use more than 53 watts.
  • Starting January 1, 2014, the standard will apply to 60 watt bulbs, which will not be able to use more than 43 watts and 40 watt bulbs will not be able to use more than 29 watts.
  • Bulbs under 40 watts, three way bulbs, appliance bulbs, and a few other specialty types are exempt.
  • By 2020, a 200% increase in efficiency is required for all light bulbs!

The Hybrid 

To meet this challenge, manufacturers have essentially developed a highbred halogen/incandescent bulb that will have all the outward appearances of our old standbys.

And the comparable stats are:

Standard Incandescent
Halogen / Incandescent
Energy Used (in watts) 100 72
Light Output (in lumens) 1150 1490
Life Expectancy (in hours) 2500 1000
Price $0.60 $1.60

We’ll let you draw your own conclusions about the cost effectiveness of the new requirements.

compact fluorescent light bulbCompact Fluorescent Bulbs

In offices and stores across America, we work and live under fluorescent lighting. Known originally for their exceptionally long life, low energy usage, annoying buzzing, and migraine inducing flickering, compact fluorescent’s (CFL’s) have improved dramatically over the years. Using a little more electricity when they are turned on, they take about 75% less energy than incandescent bulbs once the electricity gets moving through them. It takes anywhere from 30 seconds to 3 minutes to kick start a CFL, and that is why they become brighter as they burn over the first minutes.

CFL‘s now come in an array of warm and cool white light so you can find a type natural to you. How do you choose the right light? Light color is measured on the Kelvin scale (K). Lower numbers mean the light appears yellowish and higher numbers mean the light appears white and even blue.

Warm White
Cool White
Natural / Daylight
Soft White Neutral White Think Noon’s Daylight
2700-3000K 3500-4100K 5000-6500k

CFL ballasts have improved with the use of electronic ballasts and no longer make that buzzing sound. Maximize the life of the bulbs by using them where the lights are on a lot: exterior home lighting is a great use for CFL. With enclosed exterior lighting fixtures, left on for security, the bulbs burn inexpensively for months and even years. Remember to recycle these bulbs; they contain mercury, which is harmful to the environment.

LED Lighting

LED bulbs and tubes are safe and easy to use. Lasting up to 40 times longer than incandescent bulbs, LED bulbs are eco-friendly Wisconsin-style. With no mercury vapor, no harmful UV rays and no headache causing flickering LED bulbs eliminate the issues of compact fluorescent and last even longer. We started using them in recessed lighting applications where changing a bulb is a major event like vaulted ceilings. We simply swapped out LED bulbs with incandescent bulbs once, and never changed the bulbs again. That got our attention! The initial cost of the bulbs can be a little hefty, but they pay for themselves over time because they last for years. Really!

Now that you know the difference between bulbs we can make some useful comparisons.

Bulb Type:
CFL (compact fluorescent)
Halogen / Incandescent
LED (light emitting diode)
Brightness: 800 750 800
Watts: 13 43 8
Life Expectancy: 8,000 1,200 50,000
Price: $3.70 $1.60 $6.75
Annual Cost: $1.57 $5.18 $0.96

New Idea!

Going forward, we need to stop thinking about light bulbs in terms of the number of watts required to run them (i.e. 40 watts, 60 watts etc.), and instead categorize by the light produced, or lumens. Why?

While watt measurements are familiar to us all and have been featured on the front of light bulb packages for decades, watts are a measurement of energy used, not brightness.  And as lighting technology improves, wattage varies wildly with the amount of light each technology generates. Relying on watt measurements alone makes it difficult to compare traditional incandescent bulbs to more efficient bulbs, such as compact fluorescents and LEDs.

In order to help you make the transition to new bulb technology this chart bases the comparison on the incandescent bulbs we all grew up with.

How Many Lumens Do I Need?

Incandescent Bulbs
Minimum Light Output (Lumens)
40W 450
60W 800
75W >1,100
100W 1,600
150W 2,600

Reading The Label

Now we’re back to the new packaging you’ve noticed. The U.S. Federal Trade Commission now requires manufacturers to clearly label the front of their package with the bulb’s brightness in lumens.  The back of each package has a “Lighting Facts” label modeled after the “Nutrition Facts” label that is currently on food packages. The Lighting Facts label provides information about:

Light bulb label front


Light bulb label back

* Brightness * Energy cost * Life expectancy * Light appearance (for example, “warm” or “cool”) * Wattage * Mercury content

Read More

There are some excellent resources to help you learn how to compare light bulbs.

Design Recycle:

Earth Easy:

US Dept of Energy: