All about CFLs

White, blue, green, bright, dim, daylight, natural….. Who knew?! I’m talking about light bulbs. It used to just be 40 watts, 60 watts and the eye burning 100 watts. Just to throw some chaos into the mix, we has the little candle bases and the ones that were just for the fridge, oven and the hood fan. Now, that’s all changed. Well, not just now, but it has been for awhile and with a modicum of improvement. We’re into LEDs (Light Emitting Diode) and the controversial CFLs (Compact Fluorescent Light). I say controversial, not to start a debate, but it seems that there’s been a lot of chatter about them, and that’s for another day.

What I had some confusion about is the wattage, colour, and what all the info on the bulb actually meant. Here’s what I found out; the CFLs are available in 7 watt, 9 watt, 13 watt, 15 watt, and 23 watt. The “old school” reference to make sense of these new numbers is this:

7 watt CFL = 15 watt incandescent

9 watt CFL = 40 watt incandescent

13 watt CFL = 60 watt incandescent

23 watt CFL = 100 watt incandescent

Great. Got it. Now, light also has a “colour” to it – based on where it is on the colour spectrum. The higher it is on the spectrum, the more RED (hotter) the bulb is, and when it’s lower on the spectrum, the more “BLUE” (cooler) the light is. So, the HEAT that a bulb actually burns at is measured in “KELVIN” or ‘K’, and that’s degrees Celsius + 272.15 (273) degrees to equal 1 kelvin.

Here’s a quick chart for the calculation;

kelvin / degree Celsius conversions (exact):

  • kelvin = degree Celsius + 273.15
  • degree Celsius = kelvin – 273.15

degree Fahrenheit / degree Celsius conversions (exact):

  • degree F = degree C x 1.8 + 32.
  • degree C = (degree F – 32.) / 1.8


The temperature of which a bulb “burns” at is written on the bulb (or packaging), and is generally ranged as 2700K-6500K (Kelvin). At 2700K to 3000K, the light is a “warm white”.  At 4000K-4100K, the light is a bluish. At 5000K-6500K, the light is considered “daylight”.

Ok. Now I got that part. All of that is great for reference and comparison, but your lighting choice, whether it’s type of bulb, colour of light, or power of the light, is entirely up to you and your preference. Make sure that you get the right bulb for the right fixture as well. Also, remember that the CFLs are not recycleable or just thrown in the garbage – they have to be taken for safe disposal. Check your local store for that availability, or check the Recyclepedia of the Recycling Council of BC at for a location near you.



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