WIP blog

Summary

Compact Fluorescent Bulbs (typically referred to as CFLs) have finally come into their own. They are available in a variety of styles, colors, and color temperature. Bulb costs have come down from what they were a few years ago. In this blog, I will discuss each of these topics in more detail. If you are thinking about replacing some of your incandescent bulbs and saving some money on energy costs, you’ve come to the right place. I will discuss the pros and cons of bulb replacement. In the end, you will find that it makes sense to replace some bulbs but probably not all.

Energy

The primary reason to use CFLs instead of incandescent bulbs is they use 1/4 (25%) of the energy of the comparable incandescent bulb. For example, a 15 watt CFL will output roughly the same amount of light (lumens) as a 60 watt incandescent bulb.

As one reader commented, there is some controversy surrounding the topic of energy consumption of CFLs. When I get my utility bill, electricity is charged by the kWh (Kilowatt hour). I suspect most people are billed this way. If this is the case for you, a CFL that claims to be “13 watts” will indeed draw 13 watts and be billed as such. However, if you are charged based on volt-amps (VA), your realized savings for CFLs will be reduced by a factor of around two, depending on the power factor (most CFLs have a power factor of around 0.5 whereas 0.85 or higher is desired, 1.0 being ideal). For example, a 13 watt CFL might use around 26 VA. If you are billed by VA, CFLs only effectively use 1/2 the energy instead of 1/4 the energy of a comparable incandescent bulb. This is a confusing topic that is surrounded by debate. I can tell you that I personally verified on my electric meter, which reports current watt usage, that a 13 watt CFL uses around 13 watts and a 65 watt CFL uses around 65 watts. The devil is in the details, but I still feel the energy savings of CFL bulbs is real and good. For more information, you can read here and here.

Life expectancy

In addition to CFLs using less energy, the other great thing is they usually last considerably longer than their incandescent counterparts. On the packaging, you’ll see a number of hours for the bulb rating. Common CFL ratings are 6,000 to 15,000 hours. For incandescents, 750 to 1000 hours is common. However, it’s a little more complicated than this. Both CFLs and incandescent life is shortened by turning the light on and off. In the case of incandescents, the life can be considerably extended by use of a dimmer for two reasons: first, if you turn the bulb on by making it dim first and then brighter, the filament is not shocked as much. Second, operating an incandescent at a lower temperature extends the filament life. So, you can exceed the 750-1000 hour rating by 5-10x with proper dimming, perhaps even longer. For CFLs, if they are operating in a hotter, enclosed environment (e.g. poor ventilation), life can be reduced significantly. One example is the CFL spotlights I discussed below. I’ve had mixed results with bulb life on these. Because the bulbs are enclosed in a glass casing, they tend to wear out prematurely. Also, having the bulb in a spotlight reduces air circulation and bulb life. My longest lasting CFLs I bought over 5 years ago. They get used for 2+ hours a day. They have good ventilation. On the other hand, I’ve had some regular spiral CFLs last less than 3 months when operated for 1 hour/day. So, your mileage will vary.

Styles

Incandescent bulbs have been around for over 100 years. As such, they have evolved into many different styles and form factors. CFLs have only become really mainstream in the last 5 years. For example, pretty much anywhere you go these days you’ll see CFLs if you look up. CFLs are quickly becoming available in different styles. The classic CFL is the spiral. Actually, all CFLs are spirals inside. A very popular style is CFL spotlights. These too have spiral bulbs inside with a glass housing to give them the same appearance as their incandescent cousins. A few years ago, CFL spotlights were ridiculously expensive. Now, you can get a 4 pack of R30 15w CFLs (equivalent of about 65 watts incandescent lighting) for $23 which is on par with the incandescent pricing for R30 bulbs. R30 CFL spotlights are great because they are so versatile. Many rooms use this mid-sized spot light. I have replaced many of my R30s with CFLs. Similarly, R20 (small) and R40 (big) spotlight CFLs are also available. I haven’t purchased either of these sizes yet, but I intend to. Currently, R30 is the sweet spot as far as bang for the buck is concerned.

Plain spiral CFLs make up the majority of the market since they are the least expensive. Stores are constantly running specials on these bulbs. My recommendation is if you see such a special, pick up a pack. Interestingly, I have seen spiral CFLs installed in the oddest of places. Many stores put spirals in their spotlight fixtures instead of an R30 CFL. I imagine this is because of cost. It creates for an unusual look. However, I can’t help but think this is just a paradigm shift and that before long, spirals in spotlight fixtures will become stylish and R30s will become antiquated. But, I’m no expert in trends. I am happy to see so many spirals being used, as they save tons of energy. In my house, the first incandescent bulbs I replaced were those inside a fixture where you can’t see the bulb. These are prime candidates for spiral CFLs. I’ve used spirals in my garage, hallway, bedroom, and kitchen.

Another style I really like that I feel is highly underrated is the classic “A” shape CFL. This CFL is designed to look like the ubiquitous classic incandescent bulb. Of course, the “A” shape incandescent bulb got its shape as the result of “form follows function”. It could be argued that the spiral CFL is the successor. However, for old fashioned people like me, I like the “A” shape CFL. But, I think it goes beyond just the shape. The light that exits the “A” shape CFL is more distributed whereas the light from a spiral CFL can be downright blinding if you look at it. I have a chandelier in my living room whose bulbs are readily visible. It originally came with “A” shape incandescent bulbs. I have since replaced them with “A” shape CFLs. I would not dare put spirals in there because I believe five spiral bulbs hanging down from a chandelier looks tacky. That’s just my 2 cents. Two thumbs up to the “A” shape CFL, even if they cost four times more.

There are many more styles I haven’t tried including those with a mini base, globe vanity bulbs, 50w halogen replacements (with two prongs at the end), and 3 way.

Testing

After buying a bunch of CFLs, I recommend testing them when you get home. You don’t need to test every bulb, just one from each style/brand. Look for light quality, warm up time, and noise. Chances are, if it is an Energy Star bulb, it’s fine. Always buy CFLs with the Energy Star logo. More on this below. If the bulbs you picked up are no good, return them immediately. Some brands or runs are inferior, although the trend is getting better since all the manufacturers just copy everyone else’s (better) design over time. Note that when CFLs are very new, they may take slightly longer for light to first appear. It seems the ballasts need to be “seasoned”. I had one brand of bulb that took about a quarter second for light to appear after flipping the switch. After running it for a few hours, it comes on instantly now. Of course, it still needs a warm up time for full brightness.

Energy Star

When buying a CFL, make sure it has the Energy Star logo. This logo can be placed on a product when it meets guidelines determined by the DOE (Department of Energy). The first thing that comes to mind when you hear Energy Star is, well, energy. Sure enough, CFLs bearing this logo need to use 75 percent less energy than their incandescent counterparts. That’s all good, but most CFLs will meet or come close to this just by their nature. To me, the two most important things about the Energy Star logo are it ensures the bulb makes virtually no noise and that the color temperature is reasonable. Some of the earlier CFLs made a slight hum. Every bulb that I’ve gotten with the Energy Star logo has been silent. Light quality from bulbs with the Energy Star rating have been true to their label (e.g. soft white gives a convincing soft white. See more on Color Temperature below). Although the Energy Star program has undergone criticism, I still feel it’s a good standard for CFLs. I also feel it’s better to have some standard vs. no standard. So, don’t forget to look for the Energy Star logo when buying your next CFL!

Colors

Like incandescent bulbs, you can now buy CFLs that emit different colors. This should not be confused with Color Temperature which I talk about next. I haven’t tried any of the colored CFLs because I haven’t had a need to yet. I’ve seen them on the shelf so it’s worth mentioning in case you are looking to replace a colored incandescent. So far I’ve seen red, black, and yellow (bug light) and I so no reason why other colors can’t exist.

Color Temperature and CRI

You can buy CFLs with different color temperatures, too, so your whole house doesn’t look like a 24 hour Safeway. Color Temperature and CRI (Color Rendering Index) determine the quality of light the bulb emits. Temperature refers to the area on the color spectrum the bulb is emitting. For example, a candle emits a yellowish light with a temperature around 1500 K. Sunrise/sunset emits a warmer light, around 3200 K. Midday sun is very warm, around 5500 K. There’s a good chart on color temperature here. But, just because a bulb emits light at a certain temperature doesn’t mean it’ll look good. For example, a tube fluorescent bulb with a color temperature of 4100 K doesn’t necessary look like sunlight at 10am (somewhere between sunrise and midday). This is because the CRI of that tube fluorscent may be in the 70s. Some guidelines recommend a CRI above 80. To be safe, I’d get one around 85 or higher, even if it’s a premium. The CFL will last a long time, so why not spend an extra dollar or two and enjoy the light? Note that by definition, incandescents have a CRI of 100. More information on CRI can be found here and here.

This topic can get confusing quickly because CRI is often ignored. Some manufacturers only put the temperature (usually in Kelvin) on the packaging. Again, we look to our friend the Energy Star logo. You will often see terms such as “Soft White” or “Warm White” or “White” or “Bright White” or the classic “Cool White” or “Daylight”. There’s a good temperature chart that describes these. While I prefer to see both temperature and CRI on the packaging, you often have to rely on just the color label. In general, if you are looking for a CFL that outputs light similar to the classic incandescent, get a “Soft White”. This has a yellowish light that we’ve become accustom to. I’ve been quite satisfied with the Soft White CFLs I’ve bought recently. They are great for the living room and bedroom. If you are looking for something more white, such as for the garage, “Bright White” is a good choice. Truth be told, I have Cool White and Soft White in my garage and it’s all good. What’s most important is that the CRI is in the mid 80s. CRI is ultimately what will make the light feel good or feel empty.

Dimming

I am a huge fan of dimming lights. I use them in the bathroom so I can turn on the light at night and not get blinded (which also interrupts your sleep). I use them in the kids room to signify it’s bed time. I use them in the living room when watching TV. I really like CFLs, which is why I wrote this article. But, my main issue with CFLs is they are not ideal for dimming, not even if you buy a CFL designed for dimming. Before I go on, it should be noted that I haven’t actually bought a dimming CFL yet. If/when I do, I will post a follow-up here. However, I’ve researched it extensively and will summarize my findings.

Packaging

Most CFLs have packaging that has fine print stating “not suitable for dimmers”. If you see no mention of dimming on the package, it can not be dimmed. Some newer CFLs are designed specifically for dimming and are marked prominently on the packaging.

Mechanism

The typical CFL can not be dimmed. Ones marked for dimming work with a modern dimmer, say one bought in the last 10 years. Most modern dimmers use an electronic circuit that contains a triac (an electronic component). They work by altering the frequency of the current. This trick works, for the most part, for incandescent and halogen bulbs. When applied to a regular CFL, the electronic ballast can’t handle it, behaves erratically, and can damage the bulb. CFLs marked suitable for dimming have a more elaborate ballast that can work with the triac circuit.

Cost

Dimmable CFLs are noticeably more expensive than the non-dimming standard CFL. I’ve seen less expensive dimmable CFLs on amazon. I saw a some at Lowe’s, Orchard Supply, Home Depot, and my local hardware store but they are quite costly. I was discouraged by the cost combined with the other limitations of the dimmable CFL.

Dimming Range

The dimming range determines how dim the bulb can get. An incandescent bulb on a modern dimmer circuit can practically go from 0%-100%. In other words, you can get the incandescent bulbs pretty darn dim to where they are a dark orange and emit almost no useful light. In contrast, dimmable CFLs at best go down to 10% or 20% of the maximum light. Some are worse and only go down to 50%. The packaging won’t tell you so it’s impossible to know the dimming range unless you either try it or read a knowledgeable review on the specific brand bulb.

Light Quality

The biggest drawback of dimmable CFLs is the light quality is not good throughout the dimming range. When incandescent bulbs are very dim, their color temperature changes and becomes very orange or red, similar to a sunset. In contrast, when a CFL is very dim, the color tends to be more like the normal color of the bulb. That is, the color temperature does not change much throughout the dimming range. At full dimness, some are slightly pink, like some CFLs when first turned on in a cold house. Humans tend to be more comfortable with the dimming characteristics of the incandescent bulb. When a bulb emits less light, we expect the color temperature to change towards the red. If it doesn’t, it has an eerie feeling. Thus, your dimmed CFL may not produce the light you expect.

You can find more information on dimmable CFLs here and here.

Warm up time

When you turn on an incandescent bulb, you get light immediately. The bulb also reaches full brightness right away. If you’ve purchased at least one CFL, you probably noticed it doesn’t have the same behavior as an incandescent when you turn it on. There are two factors to consider here when you hear about “warm up time”:

• Time to first light : When you flick the switch to “on”, how long does it take before you get any light? This depends on the bulb, whether or not the bulb has been broken in, and ambient condition. Different makes of bulb will inherently exhibit different turn on times. Some bulbs out the box turn on pretty much instantly. Others can take 1/2 second to show light. I’ve also noticed on many of my bulbs that when they are brand new, they will take about 1/2 second to light up. But, after a few hours of use they turn on immediately. This is because the ballasts need some burn in time. In any case, the time to first light is typically not an issue since it’s never more than 1/2 second. However, I wouldn’t recommend using a CFL for applications like a really dark stairway or, worse, a refrigerator, where you really want the light to come on right away.
• Time to full brightness : After the CFL first lights up, it typically takes 30 seconds to 2 minutes to reach full brightness. It depends on the bulb brand and particularly the ambient temperature. To observe the impact temperature has on CFLs, try this: turn the bulb on and let it reach full brightness. Turn it off and then turn it on 10 seconds later. You’ll notice it is at full brightness right away. In the winter, some of my CFL R30s are pink and dim when I first turn them on. They take a good two minutes to reach full intensity. On other bulbs, even when cold they only take 30 seconds. The time to full brightness is important based on the application. If you are keeping the bulb on for a while, it’s not an issue. For applications like the dark stairway, you probably are better served with an incandescent.

One alternative bulb configuration I use a lot is to mix incandescent and CFLs in the same fixture (or on the same switch). I do this for several reasons. First, it ensures I get some decent light when I first flick the switch on. Second, even after several minutes have passed and CFLs have reached full intensity, I get a nice balance of color temperature by using both CFL and incandescent. It’s true it uses more energy than 100% CFLs, but I find it a good compromise. If you are really concerned, you can also use a lower wattage bulb in the incandescent to offset some energy costs.

Noise

Some earlier CFLs (from 5 years ago) hummed. If you buy a CFL nowadays and it has the Energy Star logo, it’s safe to assume it will be silent when on. As mentioned earlier, when you first buy a batch of CFLs, test one for noise. Return it immediately if it makes any noise.

Conclusion

CFLs are here to stay. The quality has improved over the years and is quite good now. CFLs have a place in most homes. Most likely, you should replace some incandescent bulbs with CFL if you haven’t already. However, it’s probably not practical to replace all of your bulbs. Some applications are better suited for either incandescent or CFL. In the future, I look forward to LED lighting, which promises to address shortcomings in CFL.