Posts Tagged ‘tips’

California Lighting, Overview

Thursday, July 16th, 2009

California has recently adopted energy efficiency standards that have a huge impact upon lighting. And since California has been leading the country in energy efficiency standards I thought I’d write up a quick summary of what homeowners ought to know about the changes to residential lighting since it is just a matter of time before similar rules spread to the rest of the country. Note that there are a couple adoption dates that we haven’t reached yet, so the entire Title 24 code isn’t in effect as of right now, but we may as well look to the future.

First of all, the new rules apply to all new residences and other projects that require a permit, so chances are you’re going to have to comply. Portable lighting, such as table and floor lamps, are not covered by the changes. However, all permanent lighting is covered and that basically includes anything attached to a surface. So you can’t stick a lighting track on the ceiling but control it by a cord plugged into an outlet. Lighting installed in furniture like cabinets or bath vanities is included. The big exception to this is lighting that is built into appliances, such as microwaves, refrigerators or stove exhaust hoods.

The idea is to divide lighting fixtures into high efficacy and low efficacy groups. You can install all the high efficacy fixtures you want anywhere you want. (Interestingly, to divide the fixtures into high and low efficacy the rules use just the lamp efficiency, rather than the actual fixture efficacy. Remember the efficiency/efficacy post?) To determine if a fixture is high efficacy it must comply with the following lumens per watt limits.

  • If the fixture’s lamp is 5 watts or less, it must get at least 30 lumens per watt.
  • If the fixture’s lamp is up to 15 watts, it must get at least 40 lumens per watt.
  • If the fixture’s lamp is up to 40 watts, it must get at least 50 lumens per watt.
  • If the fixture’s lamp is over 40 watts, it must get at least 60 lumens per watt.

(However, the method to determine the lumens per watt of LED fixtures has some restrictions so you can’t use the LPW of the LED module. You have to use the input power of the LED driver, but then it must also comply with the same LPW restrictions as above. You do NOT have to take the ballast for fluorescent lamps into account.)

Anything that doesn’t meet the above LPW restrictions is considered a low efficacy fixture.

In addition, there are some things that will automatically classify fixtures as a low efficacy fixture, the most important being that anything with a screw base socket is considered low efficacy. That means all fixtures using the medium or candelabra size socket that all our fixtures in our homes have been using for decades. There are some other things but the screw base socket is the most important. There is an exception for HID lamps with screw base sockets, and a huge section regarding the GU-24 base, but you probably won’t have to be concerned with those details.

Now, once you know what is high efficacy or low efficacy you can figure out what you can install in your home. There is a complex exception for the kitchen, but the basic rule of thumb is that you can only use high efficacy fixtures in your home.

Now, there are exceptions for most of your living areas:

  1. Low efficacy fixtures may be used if the circuit is controlled by a “vacancy sensor.” This is not the same as an occupancy sensor! A vacancy sensor is defined by the state as a control that can only be turned on manually and will automatically turn itself off after a preset time of 30 minutes or less unless it detects that the room is occupied or if the control is turned off manually. This explicitly excludes controls that turn on automatically, which is how occupancy sensors typically work. Also, if the control has a switch or something that allows you to choose if the turn on method is manual or automatic, it does not count.
  2. Low efficacy fixtures may be used if the circuit is controlled by a dimmer. The dimmer can be one that has several steps instead of a continuous sliding range, however, the dimmer must reduce the energy use by at least 65% at its lowest setting. That means that two-level switches with three settings (off, 1/2,  and full on) do not count. Three-level switches which have four settings (off, 1/3, 2/3, and full on) do count. Also, if the dimming circuit can be controlled from multiple locations it must be impossible to bypass the dimmer. The alternate locations can either be remote dimmers or switches that turn the lights either off or to the dimmed level only.

There are exceptions and additions, most notably in the kitchen. However, it’s fairly involved so I’ll address them in the next post.

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

Residential Fluorescent Lighting

Tuesday, July 14th, 2009

So, yesterday I posted a process I might go through to replace a fixture in my home with something more energy efficient. However, it isn’t really what I would do in my own home because I like everything to be dimmed. That includes fluorescents.

A good number of fluorescent and compact fluorescents can be dimmed using dimming ballasts. That does NOT include the self-ballasted CFLs with the screw-in base that you find at the hardware store. GE has come out with a self-ballasted replacement CFL that can be dimmed, and I’m sure others either have or will have soon their own versions. However, these can only be dimmed about 50% before they just turn off. They aren’t worth it.

Instead, I would have to buy separate dimming ballasts and install them myself. I would also have to change out my dimmers to a special versions for fluorescent lighting or perhaps install an interface. Some fluorescent dimming is done using two-wire ballasts, which would be easier to install using existing wiring, but the better dimming is accomplished using three-wire ballasts, which requires a third connection between the dimmer or interface and the ballast.

Fluorescent dimming ballasts typical have a minimum power setting of 1%, 5%, or 10%. For residential use I always recommend using 1% ballasts. This is because reducing the power doesn’t look like the same amount of light reduction. If you dim fluorescents down to a 10% it looks like it has only been dimmed down to about 30%. This just isn’t low enough for use in homes. Instead, using a 1% ballast means the lighting will look like it has been reduced to about 10%.

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

Three-Way Dimming

Tuesday, June 23rd, 2009

Yesterday, at the end of the post, I mentioned three-way and four-way dimming. For local dimmers there are two approaches: “mechanical,” and “electronic.” Mechanical and electronic refer to the dimmer type. Electronic dimmers are labeled as such and usually have LEDs on them. Mechanical dimmers are cheaper and will have no special functions and usually have a rotating dial or a slider.

For mechanical three and four way dimmers you will have to select a single location to install the dimmer, which should typically be the place from which you control the light most often. All the other locations will still be a switch that just turns the light on or off, and when turned on the lights go to the level set by the dimmer. For both three-way and four-way circuits you only use a three-way dimmer. It will have three wires instead of two (excluding the green ground wire).

Electronic dimming allows you to use remote dimmers in those locations that otherwise would have had to stay switches. However, installation is much more complex because typically there is a low-voltage wire connecting all the dimmers together. If your house doesn’t already have that wire you’re pretty much out of luck. You can use radio-controlled dimmers to eliminate the need for those extra wires, but the cost is very high (hundreds of dollars per item). Some electronic dimmer also let you use IR remote controls, and sometimes you can tie your master remote for the TV/DVD to the lights. That way you can adjust the lighting just the same as adjusting the volume on your TV. You’ll probably need to hire an electrician for those kinds of installations.

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Posted in Dimming, General Knowledge, Homeowner Tips | No Comments »