Are there certain types of older lighting fixtures into which CFLs should NOT be used?
I currently have 4 in larger table lamps (all lamps from the 1960s with narrow "harps"). The fourth table lamp is controlled by a timer - 6 hours on, 18 hours off.
But hesitated to install any in the glass globe ceiling fixtures in the bathroom and kitchen (these fixtures are totally enclosed with no apparent heat venting for the 60-75watt incandescent bulbs now used). I was concerned about potential heat-buildup problems. (Since these lights are not turned on for long periods of time, it might not be cost-effective.)
We now are using GE or Sylvania, but previously started with smaller Ikea CFLs.