Compact fluorescent light bulbs – to switch or not to switch?
You’ve heard that CFL bulbs can save you money, provide the same light as incandescent bulbs and need to be disposed of properly. But do you know how? Let’s find out!
How do they work?
CFLs use a completely different technology than traditional incandescent bulbs. Instead of an electric current running through a metal wire, an electric current is transmitted through an internal ballast and into a tube containing argon and trace amounts of mercury vapor. These elements then emit UV rays, which energize the fluorescent (phosphor) coating on the inside of the tube, releasing visible light. The initial illumination uses slightly more energy than an incandescent bulb so a slight flicker can sometimes be seen as the bulb warms up (this typically takes 30 seconds to 3 minutes to complete, depending on the bulb); however, the energy needed for continued operation is significantly lower.
CFLs with decorative covers like globe or reflector shapes have a unique design challenge and often have a slightly slower warm up time, meaning that they take longer than bare spirals to reach full brightness.
Older CFLs used large and heavy magnetic ballasts that caused a buzzing noise in some bulbs. Most CFLs today — and all ENERGY STAR qualified CFLs — use electronic ballasts, which do not buzz or hum.
How do they save me money and how much?
Since CFLs use about 75% less energy to produce the same amount of light as the equivalent incandescent, your savings on just one light fixture can amount to as much as $58 or more over the life of the bulb.
Furthermore, since CFL bulbs last about 10,000 hours, 10 times as long as an incandescent bulb, you won’t need to replace it as often – saving you money and the hassle of replacing light bulbs frequently.
Do they really provide the same amount of light?
Yes, if you choose the right bulb. The old way of buying bulbs – watts – simply lets you know how much electricity a bulb uses. Instead, shop for the amount of light output, also known as lumens. A quick look at our Bulb Selector will provide you with all the information you need!
Have incandescent bulbs really been banned?
No, but new standards are phasing out inefficient light bulbs over an eight year period ending in 2020.
How do I dispose of CFL bulbs?
Safe disposal of CFLs is actually quite easy. CFLs do contain trace amounts of mercury (about 4 milligrams, or less than 100th of the amount in a mercury thermometer), so they should not be thrown in the trash where they can be broken. Instead, many areas provide curbside collection of CFLs or central recycling locations. If this is not available in your area, we offer several mail-back CFL recycling boxes.
To put this in perspective, check out these other products you probably have around your home that also contain mercury:
– Watch battery – up to 25 milligrams
– Thermometer – up to 2 grams
– Tilt thermostat – up to 3 grams
If a CFL is accidentally broken in your home, you should immediately pick up every visible piece of glass, carefully wrap it in paper and stow it in an airtight plastic bag or sealed glass jar until you can take it to a suitable drop off location (as listed above). Additionally, you should vacuum area carpeting or rugs to pick up glass pieces too small to see and discard the vacuum’s bag. To really play it safe, ventilate the room so that any residual gas from missed shards of glass won’t accumulate in the room.
A little wary of CFLs? Want to save more?
LED lights are the next step in savings. LEDs are even more efficient at converting electricity to light than CFLs and they don’t contain any mercury or need special disposal. On top of that, LEDs have gotten significantly cheaper in recent years – some as low as $10! For more information on LED lighting, check out our previous blog posts on LED bulbs.
—The EnergyEarth Team
©2013 Energy Earth LLC. All Rights Reserved.
Yadong Li and Li Jin. Environmental Engineering Science. October 2011, 28(10): 687-691. doi:10.1089/ees.2011.0027.