How to Identify Your Reflector Light Bulb

Feb 24, 12 How to Identify Your Reflector Light Bulb

Before CFLs and LEDs, most people referred to reflector light bulbs simply as “flood lights,” or even less correctly, as “halogens.” Only designers and commercial lighting installers knew bulb shape jargon like “PAR30″ and “BR40.”

For better or worse, that’s no longer the case. Since the advent of more energy-efficient lighting technologies, selecting a light bulb has actually gotten more complicated, often requiring everyday customers to know specialized bulb terms. No longer can you unscrew a burned out bulb, take it to the local hardware store, and pick the bulb’s exact match. Now you have to ask yourself not only “What is this?” but also “What replaces this?”

Fortunately, learning the terminology and selecting the right bulb is easier than you might think.

R-Type Bulbs (R20, R30, BR30, R40, BR40)

If you’re replacing a bulb inside your home with a diameter between 2-1/2 and 5 inches, you’re likely looking for an R-Type bulb. They’re what you usually see in kitchens, living rooms, and media rooms, especially in recessed cans. R-Type bulbs have a frosted face that evenly diffuses light and eliminates glare, but unlike a PAR bulb (explained next), the entire bulb envelope (lighting nerd speak for the outside of the bulb, not including the base) is made of blown glass. The outside of the bulb is completely smooth, and the bulb is relatively lightweight since it only consists of thin glass, a filament, and a brass base.

Because LED replacements for R-Type bulbs are rare and CFL replacements are much more easily found, let’s focus on CFLs: To identify the CFL replacement you need, select an R-Type bulb based on its diameter. All light bulb diameters are referred to in eighths on an inch, so if the diameter of your bulb is 20 eighths of an inch (2-1/2 inches), you’ll need an R20 CFL. If your bulb is 30 eighths of an inch in diameter (3-3/4 inches), you’ll need an R30 CFL, and so on.

PAR Bulbs (PAR20, PAR30, PAR38)

If you’re replacing a reflector bulb on the exterior of your home with a diameter between 2-1/2 and 4-3/4 inches, you’re most likely looking for a PAR bulb. Unlike R-Type bulbs, PAR bulbs feature an aluminum reflector with a special pattern of impressions that amplifies and concentrates light in a single area. The bulb envelope is made of two pieces: The glass face and the shiny aluminum wall of the envelope. The texture of the bulb will be either rough or textured and the bulb will be heavier than an R-Type bulb due to thicker glass construction. PAR bulbs are also used indoors, especially in track lights; in a pinch, they’ll work just fine for recessed lighting as well.

Both LED PAR bulbs and CFL PAR bulbs are easy to find, though they aren’t always weatherproof like traditional halogen PARs, so be sure to check their UL listing before installing them outdoors.  You can determine if you need a PAR20, PAR30, or PAR38 based on the bulb diameter in eighths of an inch, just as you would with an R-Type bulb.

An Exercise in Reflector Bulb Identification

A reflector bulb in your living room has just burned out. It’s in a recessed light. When you remove it, you notice that the sides are smooth and the bulb is surprisingly lightweight. When you measure the diameter, it comes out to 3-3/4 inches. What is it? If you guessed it’s an R30, you’re right. Now what do you replace it with? If you guessed a CFL R30 or an LED PAR30, you’re also right!

If you can’t identify your bulb, no worries! Feel free to describe it in the comments on our blog, post it on the Facebook wall, or ask us about it on Twitter using our handle @1000bulbs.

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Buying Fluorescent Ballasts: 3 Factors to Consider

Feb 10, 12 Buying Fluorescent Ballasts: 3 Factors to Consider

Unless you’re an electrician, you’ve probably never changed a ballast. Chances are, when your garage fixture or kitchen light went out, you changed the bulbs, and when that didn’t work, you went to an overpriced hardware store and bought a brand-new fixture. Sound familiar?

Unfortunately, you could’ve saved a lot of money by switching out the ballast—an investment of only $10 to $15.

But with so many options out there, how would you know which ballast to pick? The truth is, it’s pretty simple. There are tons of fluorescent ballasts to choose from (we have nearly 300 on our site!), but most business owners and even homeowners will find it easy to wade through that seemingly never-ending selection if they concentrate on just 3 key specs: Bulb type, start method, and ballast factor.

Bulb Type

Needless to say, this is the most important part. If you don’t know what type of fluorescent bulb you’re using, you’re going to have a hard time figuring out which type of fluorescent ballast to buy. Fortunately, most fluorescent fixtures will use one of three common bulb types: An F40T12 (4′ long; 1.5″ in diameter), an F32T8 (4′ long; 1″ in diameter) or an F54T5 (46″ long; 0.625″ in diameter). If your bulbs don’t meet one of these descriptions, you’ll need to check the etching near one of the ends of the fluorescent bulb (a good idea even if you think you know the bulb type).

Start Method

Once you’ve determined what type of  fluorescent bulbs you have, don’t burn them out prematurely by choosing a ballast with the wrong starting method. As discussed in a previous article on how to extend the life of a light bulb, an instant start ballast hits the fluorescent bulb cathodes with about 600 volts every time you flip the light switch. As you might imagine, the bulb can only stand so many of those on/off switches. Consider where your fixture is installed. Offices, boardrooms, and retail spaces tend to stay lit for long periods, so use an instant start ballast should be fine, as long as you don’t switch the lights off and on more than about 3-4 times a day. Hallways, stairwells, and bathrooms are switched much more frequently, especially since the lighting in these areas is often controlled by an occupancy sensor. In these areas, it’s best to use a programmed start ballast, which will heat the bulb cathodes more slowly and prolong its life.

Ballast Factor

Finally, you need to consider light output. “What?” you say. “You mean the bulb isn’t exactly the brightness it says it is on the label?” Nope. The light output shown on a fluorescent bulb’s label, expressed in lumens, is figured using a normal light output ballast with a ballast factor between 0.77 and 1.1. A normal ballast factor is usually the right option, for “normal” circumstances. But if you don’t need your room quite as bright, you can save electricity by using a low output ballast with a ballast factor below 0.77. On the other hand, if you are lighting a warehouse or manufacturing facility where brightness is important, you will need a high output ballast with a ballast factor above 1.1, which will push the bulb to be 10% or more brighter than stated on the label.

Of course, if you need something more specialized like a sign ballastdimming ballast, or circline ballast, you’ll likely need an equally specialized electrician. The same principles still hold true, however, so if you need to call an electrician, at least he’ll be impressed by how much you know!


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Understanding Life Hours, Part 3: How to Extend the Life of Your Bulbs

Jan 27, 12 Understanding Life Hours, Part 3: How to Extend the Life of Your Bulbs

The third and final part in a series about life hours and how you can use this spec to inform your purchase and maximize the life of your bulbs.

If you’re a lighting nerd like most of us at, you’ve likely heard of the 110-year-old Centennial Bulb in Livermore, California. If (more likely) you’re not a lighting nerd, here’s the brief rundown: The Centennial Bulb was installed in a firehouse over 110 years ago and still hasn’t burned out. It’s not known exactly how it has lasted so long, but there are a few good clues: One, it has only rarely been moved; two, it has been switched off only a handful of times, and three, it is operated at very low power.

The two previous articles in this series explained how manufacturers determine life hours and how life hours and warranties are two different things. This third and final article in the series explains how you can make your light bulbs last longer. We can’t guarantee they’ll last 110 years (in fact, we can almost guarantee they won’t), but by following a few tips you can easily double or triple the life of your bulb. One caveat, however, because not all light bulbs use the same technology, these tips do not apply to all bulbs.

Don’t move it! Light bulbs get hot. Really hot. And when metal (which makes up a bulb’s filament) gets hot, it gets brittle. The more you handle a bulb with a brittle filament, the more vibration you subject it to, making the filament much more likely to snap. This doesn’t apply only to handling the bulb; it also applies to placement. Any bulb installed in a place that moves also moves. The swish of a ceiling fan or the slam of a refrigerator door, while barely heard by you, is a light bulb’s death knell. It’s for this reason that you may have seen special bulbs with reinforced filaments marketed as “ceiling fan bulbs” and “appliance bulbs.” As you might have picked up, this rule only applies to bulbs with filaments, like incandescent and halogen bulbs.

Leave it on! This may sound contradictory to common sense, but it’s not. Every time you flip a switch, you are blasting your light bulb with power. That poor little filament is forced to go from room temperature to 5000° F in a fraction of a second! You do that too many times, and the filament will literally crack under the pressure. This also goes for ballasted bulbs like linear fluorescents, CFLs, and HID lamps. In the case of an instant start fluorescent ballast, you’re hitting the fluorescent tube cathodes with 600 volts every time you flip the switch. After so many power cycles, the lamp will fail. Keep in mind, however, that while this trick will prolong the life of your bulb, it could also increase your electricity usage.

Operate it at low power. This may be the real secret to the Centennial Bulb’s longevity. Less power means less heat, which translates to less stress on a bulb filament. If you live in the United States, your house is operating on ~110V, so if you buy a bulb rated for 130V, you’ll be hitting the bulb with 15% less power than it is designed to handle  (130V – 15% = 110.5V). You can stretch this principle even further with a dimmer switch. When you dim a bulb, you are lowering the voltage delivered to the bulb filament, putting it under less stress. This also applies to fluorescent technology, but in a slightly different way: Unlike an instant start ballast, a programmed start ballast supplies a much lower starting voltage and heat to the lamp.  If you switch to this type of ballast, you could extend the life of your fluorescent bulbs by over 30%.

Finally, remember that the aim of extending bulb life, in most cases, is to save money. Is it really worth it to make that incandescent bulb last forever by dimming it and leaving it on for longer periods? In many cases, it’s better to switch to a more efficient CFL or LED. But if you’re a die-hard incandescent fan, or want to recreate your own Centennial Bulb, these tips will come in handy.

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Understanding Life Hours, Part 2: Life Hours vs. Warranties

Jan 20, 12 Understanding Life Hours, Part 2: Life Hours vs. Warranties

Part 2 in a series about life hours and how you can use this spec to inform your purchase and maximize the life of your bulbs.

In the previous article, we discussed how manufacturers determine life hours differently for incandescents, fluorescents, HID lamps, and LEDs. Switching to something less technical, this article will give you information that is much more practical, namely, how to choose the right light bulb for your application.

Life hour ratings are often confused with warranties, but unlike a warranty, a life hour rating is not a guarantee of the life of the bulb. If your light bulb is rated for 1,500 hours and has a warranty of one year, you’ll be hard pressed to get the manufacturer to reimburse you the cost of the bulb after one year and a day, even if you only used the bulb 1,499 hours. Likewise, the manufacturer would be likely to reimburse you if your bulb failed one day short of a year but you used the bulb 1,501 hours. (On a side note, if you set a stopwatch every time you screw in a light bulb, you need to find a new hobby.)

So when you go to buy a light bulb, should you just ignore the life hour rating and look for the longest warranty? That depends on your application. If you’re a homeowner looking to get your full return on some expensive new LED bulbs, you’d be wise to look for an ironclad warranty. But if you’re outfitting an auditorium with 50 foot ceilings, you’d be better off selecting bulbs with the longest life hours. Why? A warranty isn’t much consolation when you still have to climb 50 feet to change a bulb.

Several major lighting manufacturers don’t even offer warranties, and if they do, they tend to make the warranty documentation difficult to find and contingent on more variables than most people care to read. Sylvania’s Quick60+ Warranty, for example is a system warranty, meaning it only applies if you are using both Sylvania lamps AND ballasts in your application. If you’re using Advance ballasts with your Sylvania lamps, then sorry, you’re out of luck!

The other two of the “big three,” GE and Philips also tend to be stingy with their warranties. However, a lack of a warranty doesn’t mean a low-quality bulb. In fact, if you’re into the big brands, just the opposite could be argued. You’ll remember from the last article in this series that life hours represent roughly the amount of time it took one half of a test batch of bulbs to burn out. The other half hadn’t yet burned out. Think about your application, how often you’re going to use the bulb, and how likely you are to hold on to your receipt. You might find yourself less concerned with warranties than you thought.

In the next and final installment of this series, we’ll tackle the fine art of making your bulbs last longer, sometimes longer than either warranty or life hours. A hint: It’s not really an art at all.

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Understanding Life Hours, Part 1: How Are Life Hours Determined?

Jan 16, 12 Understanding Life Hours, Part 1: How Are Life Hours Determined?

Part 1 in a series about life hours and how you can use this spec to inform your purchase and maximize the life of your bulbs.

The term “life hours” sounds simple but is one of the most misunderstood of all lighting terms. A life hour rating isn’t a warranty or guarantee of a light bulb’s life, so the life hour rating you see on a bulb’s packaging isn’t necessarily how long the bulb will last in your fixture.

A manufacturer’s projection of life hours has to take into account many variants including the calibration of manufacturing equipment, temperature fluctuations, and material quality, to name just a few. By using a big enough test sample, manufacturers hope to account for any manufacturing inconsistencies, making their rating as accurate as possible.

Manufacturers determine life hours for filament lamps, fluorescent tubes, HID lamps, and LED bulbs all in slightly different ways. Here’s the rundown:

Filament Lamps (Incandescent and Halogen)

  • Manufacturers test a group of sample lamps by burning them continuously.
  • The point at which 50% of the lamps fail is the life hour rating.

Fluorescent Lamps (Linear, U-Bend, Plug-In)

  • Manufacturers test a group of sample lamps by burning them for 3-hour intervals.
  • The point at which 50% of the lamps fail is the life hour rating.

HID Lamps (Metal Halide, HPS, Mercury Vapor)

  • Manufacturers test a group of sample lamps by burning them for 10-hour intervals.
  • The point at which the lamps meet 40% of their original lumen output is the life hour rating.

LED Lamps

  • Manufacturers test a group of sample lamps by burning them continuously. Like HID lamps, LEDs aren’t allowed to burn out.
  • The point at which the lamps meet 70% of their original lumen output is the life hour rating.

In the next part of this series, we’ll show how you can use this information to inform your light bulb purchase.

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What are Lumens, Candlepower and CRI

Jun 20, 11 What are Lumens, Candlepower and CRI

When looking through a selection of light bulbs, it can become confusing to compare different lamps to each other, but understanding bulb terms can help in finding the right lamps for the fixtures in a home or business. The following are the most basic terms to consider.

Wattage and Voltage: Watts and volts are sometimes mistaken as measurements of light output. This comes from the familiarity of people with the incandescent light bulb, which has been the standard in lighting for decades. This long history has trained the average homeowner to think of lighting an area in terms of whether it needs a 40, 60, or 100-watt bulb. Even today, manufacturers of CFLs and LED light bulbs tend to stress the incandescent equivalent wattage rather than the actual, much lower wattage of the bulb.

Lumens and Candlepower: As the lighting industry shifts away from incandescent lighting, it will become more and more important to focus on the actual light output of a bulb rather than how it compares to an incandescent light bulb. Lumens, also shown as lm, represent the actual amount of ambient light coming from a lamp. The higher the amount of lumens, the more “lit up” a room will be. Candlepower, on the other hand (measured in candelas), is a unit of measurement that stands for the luminous intensity going in a specific direction from a light source. The latter, usually seen on reflector-type bulbs, is most important when the actual “punch” of the concentrated beam of light is more important than how much of an area it illuminates.

Coloring Rendering Index (CRI) and Color Temperature (CCT): A bulb’s color rendering index is a representation of how well the lamp will reproduce colors. Lighting sources at the low end of the index, such as low-pressure sodium lamps (CRI 20-30) tend to wash out colors and are best used in commercial applications where accurate color rendering is not important. An incandescent or halogen light bulb, on the other hand, is considered to have a “perfect” CRI of 100. Linear fluorescents and compact fluorescents (CFLs) usually fall in the 80 to 90 range. While CRI represents how accurate a light source is, color temperature (represented in degrees Kelvin (K)) represents the character of the light source. At the low end, a color temperature of 2600-2700K creates a warm light character like that seen in incandescent bulbs; a higher color temperature of 4100-5500K creates a whiter light like that most often seen in office buildings.

Life Hours: Life hours represent the life expectancy of any given manufacturer’s light bulb. This, however, does not represent how long every bulb will last, but is rather the number of hours it took one-half of a batch of test lamps to burn out. Though this is a good indicator of a light bulb’s life, it is not a guarantee and should not be confused with a warranty.

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