Lamping Guide FAQ + Resources
- How did Eleek come up with average prices?
- Where did Eleek get information about lumen output and efficacies?
- Can you compare all lamps equally?
- What makes halogen MR16s and LEDs different from other lamps?
- How can I find out more about lighting color and color rendering?
- I am concerned about the fact that fluorescent bulbs contain mercury. Although they save energy compared with most other competing technologies, is it worth the risk?
- Where did Eleek get its information about energy related carbon dioxide output?
- Does Eleek have any recommended resources for further exploration?
How did Eleek come up with average prices?
We compared pricing of various brands on the site of a single online retailer: www.bulbs.com. While there may be more price variation between retailers, our research indicated that this method offered a good overview of pricing.
Where did Eleek get info about lumen output and efficacies?
Most lumen information we derived from manufacturer specifications, and we calculated efficacy in the standard way—dividing lumens by respective wattage. There are some pre-built lists available, such as that on Wikipedia; however, keep in mind that it may be difficult to source lamps that have lumen to watt ratios as high as some listed on sites like this.
- Wikipedia : Luminous Efficacy
- Philips Lighting Company 2008 Lamping Specification Charts
Note: Eleek does not endorse specific lamping brands.
Can you compare all lamps equally?
One of the goals of our chart is to present an “apples to apples” comparison of different lamping types. That said, different lamps are used for different purposes and their perceived strengths and weaknesses can vary accordingly. For instance, not all lamps are useful for outdoor applications; and some, like LEDs and MR16s, have lumen counts that are not easily comparable to ambient lamps such as most compact fluorescent and incandescent lamps. Consider the Guide a general tool. If you need more information, we have a list of resources here that can get you started.
What makes Halogen MR16 bulbs and LEDs unusual?
Most manufacturers don’t publish lumen counts for halogen lamps fitted with MR16 reflectors , since they concentrate light into a spot. The lamp still produces the same number of lumens as a naked bi-pin halogen; but the concave reflective surface surrounding the bulb concentrates the area of illumination, making the lumen count somewhat misleading. If a spot is what you need, however, you’ll be very happy to have those lumens concentrated rather than having to use more power to light up a larger area.
Similarly, LEDs often use reflectors and as such their lumen count can also be difficult to translate for real-world applications, making it easier to compare them with halogen spots than ambient lamps. Straight calculations of efficacy (efficacy=lumens divided by watts) can be misleading, as LED light output is particularly sensitive to how it is integrated into its final fixture. LED ballasts can reduce efficacies depending upon a number of variables such as reflector design and how successfully it manages to disperse LED heat generation. Because of this, you may want to consider investing in LEDs made by trusted manufacturers and implemented by lighting designers with expertise in LEDs.
- Weir, Bernie. “Trends and Tradeoffs in Powering LED Luminaires” LED Journal Nov/Dec 2008
- Reo, Ann. “To LED or Not to LED?” Architectural Lighting Magazine, Sept 2008
- U.S. Department of Energy: Energy Efficiency and Renewable Energy, Solid State Lighting
- The Lighting Research Center
How can I find out more about lighting color and color rendering?
There are a number of excellent sources out there, including some subjective measurement surveys to find the most visually satisfactory products. Here are a few we used the most:
- Wikipedia on the Color Rendering Index
- Popular Mechanics Compact Fluorescent Light Comparison 2007
- The Department of Energy, for general news and information about LED light color & color rendering
I am concerned about the fact that fluorescent bulbs contain mercury. Although they save energy compared with most other competing technologies, is it worth the risk?
Although mercury in the environment is a serious concern, at this time fluorescents still provide more benefits than drawbacks compared to most incandescents. The amount of mercury in fluorescent bulbs is much less than it used to be, and if disposed of properly and not broken, mercury is kept out of the natural environment entirely. Even if large amounts of bulbs are badly disposed of and broken, studies have shown that given their energy savings compared with incandescent bulbs they will create a net reduction in mercury pollution in areas supplied by coal power, since coal energy is the largest source of mercury in the environment. If you are concerned about mercury (and we all should be), please consider all the ways in which you can reduce your use of electricity overall, and please support renewable power production in every way you can. Some utilities offer wind power offsets, for instance. You may also want to consider using LED bulbs, which do not contain mercury.
- Spatial Assessment of Net Mercury Emissions from the Use of Fluorescent Bulbsby Matthew Eckelman, Paul Anastas and Julie Zimmerman. Environmental Science & Technology 2008
- EPA directions on cleaning up broken fluorescent bulbs
- Additional information and facts about fluorescent mercury content and emissions from Wikipedia
Where did Eleek get its information about energy related carbon dioxide output?
The Carbon Dioxide Information Analysis Center provided the formula for calculating carbon dioxide footprint based on coal energy consumption. Approximately 49% of the electricity produced in America is generated by coal. According to the U.S. Environmental Protection Agency, coal-fired power plants are the largest single man-made source of mercury pollution in the U.S., and are the largest contributor of hazardous air pollutants. If your electricity is generated from resources other than coal, this calculation may not necessarily apply to you (however, it is still beneficial for all of us to reduce our energy consumption).
- Carbon Dioxide Information Analysis Center
- Energy Information Administration for energy generation statistics in the United States
- Energy Information Administration for data on coal power in the United States
- “Coal Plants = Toxic Mercury” by the Sierra Club
Yes—here they are, in no particular order:
- On Fluorescent Mercury Content: Information and Facts from Wikipedia
- On Coal Power: “Coal Plants = Toxic Mercury” by the Sierra Club
- For Compact Fluorescent light quality testing: Popular Mechanics Comparison Report 2007
- For in-depth information on LED development: U.S. Department of Energy, Solid State Lighting
- For in-depth, general lamping technical information: The Lighting Research Center