Skip to content

Compact Florescent Light Killers

21 March 2012

I will be the first to admit that compact florescent lights (CFLs) are not perfect and can be quite confusing. Yet I do feel that their energy and money savings make up for this. Seattle City Light has a great page all about CFLs. I was most interested in their “CFL Killer” table, which is pasted below. I would like to highlight two common problems that are super easy to fix. One is that regular CFLs don’t work well with dimmer switches. It is worth buying CFL bulbs specifically designed for dimmer switches. Second is poor quality and off-brand CFLs. You need to make sure that your CFL is up to standard, which means you need to purchase Energy Star rated bulbs. As seen below off brand CFLs can shorten the life of your bulb by 25% to 75%. Woofta! I hope this helps answer some questions.

CFL Killers Life reduced by:


Best Option
Dimmer Switches 85% – 100% – definitely worth investing in the right bulb for the fixture. Unless your CFL specifically states that it is rated for use with a dimmer, its life on a dimmer will be short.  Even if you leave the dimmer switch up all the way, it will still drastically shorten the life of an ordinary CFL. Look for bulbs that are specifically designed for use with dimmer switches.
Recessed cans and enclosed fixtures 15-25% – investing in the right bulbs will pay off.  Standard bulbs will have a limited life. CFLs are more sensitive to heat than ordinary bulbs.  Unless your CFL is specifically rated for use in enclosed fixtures and recessed cans, the heat build-up will cause early failure of the ballast. Use reflector CFLs for recessed cans.
Use CFLs that specifically state that they can be used in enclosed fixtures.
Motion sensors 25% – 35% A CFL usually has about 7,000 on-off cycles in it.  It’s up to you how you use them.  Some motion sensor and photo cell fixtures can be particularly hard on CFLs due to their repeated on-off cycling. If your fixture turns on and off more than 20 times in a 24 hour period, it’s not a good candidate for a CFL.
Poor quality or off-brand CFLs 25-75% Not all CFLs are created equal.  Off-brand products have not gone through the Department of Energy’s ENERGY STAR® testing process. Look for bulbs with the ENERGY STAR® label insuring that it’s met strict US DOE testing requirements.
Jostling and vibration 10-40% (depends on the severity) CFLs are not designed for use in fixtures subject to high levels of vibration as it can cause the electronic components in the ballast to separate. If you suspect that vibration may be shortening the lives of your bulbs beyond your tolerance, do not use a CFL in that fixture.
Bad house wiring 85% – 100% While this is an uncommon situation, cases have been recorded where loose neutral wires and improper system grounding have led to voltage fluctuations that have caused early failure of the ballast. If you suspect that this may be a problem, contact an electrician to make sure your home wiring is sound.

No comments yet

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

%d bloggers like this: