Posts Tagged ‘complaints’

California Lighting, Final Thoughts

Wednesday, July 22nd, 2009

All in all, the California Title 24 legislation is pretty progressive. With regard to lighting, it is really focused toward making you think about the lighting in your home. You really have two primary approaches toward lighting your living space: either committing fully to fluorescent lighting or using dimmers throughout your home for energy savings. The state is also clearly looking forward to LED lighting, but frankly the industry isn’t ready to support that yet. However, the rate of growth is so strong it will only be a few more years before that changes.

If you commit to fluorescent lighting remember to consider the color temperature and color rendering index of each lamp. Right now people aren’t accustomed to the way everything appears under fluorescents, but I think in a generation the quality of fluorescent lighting will become our new “normal.” With technological advances the fluorescent and LED sources will improve and either the manufacturers will make them more like natural light or (more likely) we’ll just grow to accept the spectral profiles of those sources.

However, if you aren’t ready to make that leap yet you can use dimming systems. I think everyone should use dimming in their homes even if they don’t care at all about energy efficiency, since I believe the quality of life benefits shouldn’t be ignored.

And instead of just using local dimmers, hopefully this will stimulate the use of wider-ranging lighting systems. System that enable you to program lighting for entire rooms rather than just adjusting each circuit. There are countless options out there so don’t feel limited by the adoption of more stringent energy efficiency standards as they progress from the west coast eastward.

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Posted in Dimming, Fluorescent (and CFL), General Knowledge, Homeowner Tips, Incandescent | No Comments »

Finding a More Efficient Lamp

Monday, July 13th, 2009

As I was finishing up my previous post about efficiency pitfalls, I realized that I had started an example which could be useful in and of itself. So I’m going to take it a step further.

Situation Summary: I have an existing fixture in my home that I want to make more efficient. It is a surface mount that looks like a glowing bowl stuck on the ceiling. It uses two 75 watt bulbs. The light in the room is more or less acceptable, although it is a little dim and I would like it to be slightly brighter if possible. Looking up the information about the existing bulbs, I see that the total lumen output of both bulbs is 2,340, so I know I want to at least match that and if possible increase it slightly.

I could have just substituted my 75 watt incandescent bulbs for 20 watt self-ballasted CFL bulbs, based on the label on the box that says to replace my 75 watt bulbs with the 20 watt CFLs. The energy savings is good, since now my fixture only uses about 40 watts instead of 150, meaning I’m saving about 73%. However, the mean lumens of those CFLs are only 965, so the new total would only be 1,930. Since I thought the room was already a bit too dark, going from 2,340 lumens to only 1,950 is going to make me unhappy over the long term, and I run the risk of someday switching back to the incandescents. (Note, the initial lumens of this bulb are listed as 1,150, which brings my total up to 2,300 and almost a perfect match to my existing. However, that is initial lumens and won’t last for the lifetime of the bulbs. They will continue to depreciate and my room will get darker and darker, so it is an unfair comparison to use the initial lumens.)

Fearing the decreased light output, I buy two 26 watt self-ballasted CFLs because I see that the mean lumens for those are 1,365, meaning my new arrangement will provide me 2,730 lumens! I’d be saving about 65% energy by using 52 watts, but I discover that the 26 watts lamps are bigger than my existing incandescents and they won’t fit in my fixture. The bowl hits the ends of the lamps preventing me from reattaching it.

Now I recall reading my own post from yesterday. I go to my local electrical supplier and buy a replacement fixture for the existing. Based on my post, I’m now using a long “blob” instead of a bowl on the ceiling. I get 2,772 lumens, so I am very happy with the new lighting level in the room, and I’m only using 32 watts. That’s a savings of about 75%, better than the savings from those CFLs! Granted, I’ve now bought a new fixture as well as lamp, and I had to be very careful about my lamp and ballast choice, but I’m much happier with the final result.

Of course, this just shows that in order to make the best choice you need to have some knowledge, but that’s what this blog is for. Feel free to send me questions or reply to my postings to get more information.

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Posted in Fluorescent (and CFL), General Knowledge, Homeowner Tips, Uncategorized | 4 Comments »

Color Temperature Basics: Summary

Friday, July 3rd, 2009

I hope the previous discussion of color temperature is useful. There is a lot of technical information that goes into understanding and effectively using color temperature. Here are some key points that you can rely on as being useful to you.

  • Color temperature usually only matters for non-filament sources: fluorescents, compact fluorescents, metal-halide, induction, etc. (and it’s really the correlated color temperature, so it will be labeled CCT)
  • There are many options for color temperatures of fluorescent lamps. Don’t just pick something up because it’s on the shelf. Think about the space and select a color temperature that is going to help. You may need to go somewhere and see some samples of different color temperatures before you decide.
  • Higher color temperatures give a greater perception of brightness. There are complex optical reasons for this that you don’t really need to understand, just know that a CCT of 4000K will appear brighter than a CCT of 3000K even if the measurable quantity of light is equal.
  • Color temperatures higher than 4200K tend to be perceived as too cold for comfort. They are useful for very visually-intensive tasks, so you find them in manufacturing facilities where there are lots of small parts being used, but not homes or professional offices.
  • Color temperatures lower than 3000K will seem to be too amber during the daytime. Things may appear to be visually “mushy.” However, at night 3000K can be very nice.
  • Typically, places used and lit during the daytime benefit from higher color temperatures and places used and lit during the nighttime will benefit from lower color temperatures.
  • Dimming fluorescents will not shift the color like it does with incandescents and halogens. This is actually a negative, since during the daytime you need higher lighting levels and a higher color temperature to be comfortable, but in the evening you’ll want to turn down the intensity and color temperature.
  • I have found the best middle of the road CCT for fluorescents is 3500K. No single color is going to be the best for every purpose, but 3500K is a pretty decent compromise.
  • If you have fixtures will multiple lamps you can mix a warm and a cool to try control the balance of “white” light better. However, don’t mix colors from a single-lamp fixture to the next since it will be start to look just plain weird.

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Color Temperature Basics: Fluorescents

Thursday, July 2nd, 2009

The real meat of the color temperature discussion is with regards to fluorescent and HID (high intensity discharge) sources. Color temperature is tricky for fluorescents because it is based on heating the black-body object to get a color. However, fluorescent sources do not have an object to heat since there is no (functional) filament. Instead, it is a gas discharge process, so color temperature doesn’t really apply. Instead, we use the CCT, or “correlated color temperature.” This is just an approximation of the color temperature the manufacturer is trying to achieve with their mix of phosphors inside the lamp.

The reason CCT is important is because there are so many different phosphor mixes that can be used. Unlike incandescent lamps, there is a wide range of mixes and each mix, relating to a CCT, establishes what we see as “white.” It is this establishment of “white” that makes any and all of this matter.

By using a different phosphor mix, we make white objects appear either warm or cool, based on the (correlated) color temperature of the light source. All other objects, from artwork to skin color, reflects the same “bias” toward the color we have established as white light. This is why early adoption of fluorescent office lighting was so painful. The phosphor mix and color temperature of the light was shifted so far toward the higher, cool end of the lighting range people didn’t like the way things looked. There were other problems, but the main thing most people took away from the experience was an association of fluorescent lighting being “cold.”

However, we could just as easily make our fluorescent lighting “warm” by using lamps with a CCT with a lower number. For example, you could use lamps with a CCT of 2700 to try to match the incandescent lamps you are used to having in the home. In my experience, most people don’t like a fluorescent lamp with a CCT of 2700K either, since it doesn’t look like a regular incandescent lamp with a color temperature of 2700K. That’s part of the “correlated” aspect, and there is also some color rendering issues which I’ll discuss in following posts.

The trick to good fluorescent and compact fluorescent lighting is finding the CCT you like for any particular use. In more residential settings, a 3000K lamp may be preferred, whereas in an office or kitchen 3500K may be better. You can’t just pick one and use it for everything, although that would be preferable to not picking at all and just installing whatever shows up. Selecting the right color temperature is a part of the lighting design process.

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Full-Spectrum Lighting Health Claims

Friday, June 26th, 2009

I realized there are a couple of other things to mention, but so much of what I’ve been hearing relates to the health claims that I want to address that today and let the other things spill over into next week.

When the full-spectrum term was coined in the 1960′s it referred to both visible light and the invisible ultraviolet (UV) light. The health claims of full-spectrum lighting mostly revolve around the UV end of the range. All fluorescent light emits UV radiation, since it is the UV rays created by the mercury vapor striking the phosphor coating which makes a fluorescent light work. Full-spectrum lamps just emit more UV radiation than normal lamps.

The typical recommendation is to avoid as much UV exposure as possible. UV exposure has been linked to sunburn and skin cancers as well as cataracts in the eye. UV exposure also cause the degradation of textiles, paints, and architectural materials. Museums typically require all wavelengths shorter than 400nm to be filtered out of artificial lights.

  • Technical info, you may ignore: Visible light is 760 nm to 380 nm, UVA is light wavelengths between 400 nm and 315 nm, UVB is light wavelengths between 315 nm and 280 nm, UVC is light wavelengths between 280 nm and 100 nm. Visible light is broken down as red from 760 to 610 nm, orange from 610 to 591 nm, yellow from 591 to 570 nm, green from 570 to 500 nm, blue from 500 to 450 nm, and purple from 450 to 360 nm. These are defined by the International Organization for Standardization in ISO 21348:2007.

Full-spectrum lighting to treat SAD (seasonal affective disorder): Using full-spectrum lighting does not fit into the standard treatment of SAD, which involves exposure of the eye to a white light source in a light box. The light box typically generates 10,000 lux and it is used for about 30 minutes. Lower intensities might be used for longer periods. At 10,000 lux, any light source will be effective to treat SAD. Most importantly, these light boxes shield out UV rays, which is the opposite of using full-spectrum lighting. Using full-spectrum lamps in normal overhead lighting will have no effect upon SAD treatment.

Full-spectrum lighting and vitamin D production: Vitamin D is important, but the production is stimulated by the UVB band (315 to 280 nm) of light. Full-spectrum lamps typically use phosphors to generate UVA radiation (400 to 315 nm), and they typically peak around 355 nm. You are better off eating fish and dairy products and–if you’re really worried–taking supplements. Various studies have been done showing exposure to full-spectrum lighting for vitamin D production is impractical. For example, to spike vitamin D production in your body you may need 30 hours continuous exposure to a full-spectrum lamp to get the same affect as 22 minutes of mid-day sunlight. Or, 8 hours of full-spectrum office lighting has about the same UVB exposure as 1 minute of direct sunlight.

Also, the UVB rays that are generated by full-spectrum lamps often don’t bounce off surfaces. That means that if you are hoping to increase your UVB exposure you will only get it when in direct line of sight from the lamp to your skin. Everything else is absorbed by the materials and clothing around you. That also increases the deterioration of those materials.

In summary, there really are no serious health benefits to using full-spectrum lighting.

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Posted in Fluorescent (and CFL), General Knowledge, Homeowner Tips, New Tech | No Comments »

Intro to Fluorescents, Day 3

Wednesday, June 10th, 2009

Following up on yesterday’s post, there are fixes for the two common complaints regarding color and flicker.

  1. Color is tricky. The details regarding color for fluorescent lighting is complex and I’ll address it in another post, but for now just look for two things: the lamp’s color temperature and its CRI. The color temperature will be four digits followed by a “K,” such as 3000K or 4200K. The CRI will be two digits and may or may not be labeled, such as 72 or 86. For color temperature, select from three options: 3000K, 3500K, or 4000K. The 3000K will appear warmer, supporting reds and oranges better. The 4000K will appear cooler and brighter, supporting the blues and greens better. It comes down to personal preference, and you should see each before making a selection. For the CRI, select the highest number available, hopefully higher than 85. The color temperature and CRI will be printed on the bulb if it isn’t on the box. GE uses a code like F32T8/SPX35/ECO, where the SPX means a CRI of 86 and the 35 means a color temperature of 3500K. Philips and Sylvania use similar codes: F32T8/TL835/ALTO for Philips or FO32/835/XP/ECO for Sylvania. The 8 means a CRI of 86 for Philips and 82 for Sylvania (the addition of XP raises it to 85) and the 35 means a color temperature of 3500K. Those three codes will basically provide you the same lamp.
  2. Flicker is not tricky. Flicker can be solved by using electronic instead of magnetic ballasts. Older, magnetic ballasts operate at 60 Hz, as discussed yesterday. Electronic ballasts operate at thousands of cycles per second, so it is impossible to see the flicker. Plus, they are much quieter than older ballasts, so if you hear a ballast buzzing, change it!

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Posted in Fluorescent (and CFL), General Knowledge, Homeowner Tips | 1 Comment »

Intro to Fluorescents, Day 2

Tuesday, June 9th, 2009

Since fluorescent lighting is much more efficient it would seem to be good way to save on energy consumption. However, most people don’t want to switch to fluorescents. There are basically two main complaints.

  1. I hate the color. It’s not so much the color as the lack of color. Incandescent, like sunlight, has a wide “spectral distribution,” which simply means it looks white because it has all the colors of the rainbow mixed together. Because the light in a fluorescent lamp is generated by the phosphor coating on the inside of the lamp (see yesterday’s post), rather than incandescence, the spectral range is reduced. Think of a rainbow with parts missing. Objects and people that you see will looked dingy if the colors on them are not present in the fluorescent lamp’s “rainbow.” Although most people can’t quite put their finger on it, that’s why they think that things just look bad under fluorescent lights.
  2. I hate the flickering. The “flicker” that some people see is a real problem and can lead to headaches as well as annoyance. It is caused by the ballast. Old ballasts operate at 60 cycles per second, the same as the cycle supplied from the power company. Each end of the lamp is actually firing off 60 times per second, which is slow enough some people can see it, usually in their peripheral vision.

There are good fixes for these complaints, which is tomorrow’s posting topic.

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Posted in Fluorescent (and CFL), General Knowledge, Homeowner Tips | No Comments »