Why are some self-ballasted lamps/bulbs dimmable and some are not? What would happen if an "undimmable" lamp was put into a socket with a dimmer? Also, I'd like to know if a self-ballasted fluorescent lamp that says it uses only 25 watts but says to use in 100 watt applications can be used in a 60 watt application? Most light fixtures say "use only 60 watt bulbs" but I figure I should be able to increase the light by using a fluorescent that puts out more lumens but uses less watts.

There is no problem using a 25W self-ballast lamp in a 60W application (vs a 100W application). However, the area will be brighter.

You cannot use a self-ballast lamp with a dimmer (unless the dimmer function is not used). The reason is because self-ballast lamps require full voltage to maintain an arc that gives off light.

Normal lamps use a resistive element and the dimmer varies voltage to vary the temperature of the resistive element. Full voltage makes the resistive element the hottest. The hotter the element the more light produced.

Thank you bhayne,
Our historic church seems very dark and the chandeliers have sockets for three 60 watt bulbs and one 200 watt bulb. The trustees were afraid to install higher wattage lamps in these sockets for safety reasons. Guess we can now try blocking the dimmer slides and buy the highest fluorescents we can find for the 60 watt sockets. Thank you again.

For safety reasons, rather than blocking them, I would remove the dimmers. You can use the largest compact fluorescent bulbs you can fit in the sockets. I believe they make 40 watt CFs that will give you 200 watt equivalent light.

I just went to a trade show and GE lighting was advertising their new dimmable self-ballast fluorescent lamp. Cost is quite high at $16.

Another thing; the lamp was surprisingly hot. I would expect the heat from the ballast as the fluorescent bulb produces little heat. Just be aware of that and make sure you read the bulb's directions if your tending that way.

I am a Certified Lighting Consultant. Here is the scoop on lamping.

1. Self ballasted fluorescent lamps can be used with dimmer if you purchase a dimmable fluorescent lamp. This is market on the package.

2. Wattage is a measurement of power consumption only. It has nothing to do with brightness. That is called lumen. All new lamp packaging has these new markings on them by law.

3. Fluorescents are a terrific form of lighting and energy savings. The fact that Kelvin Temperatures are now very prevalent, the type of lamp you buy should be purchased around the highest lumen level, with the power consuming wattage is no higher than the socket can handle, and that the Kelvin Temperature of the lamp (marked from 2700K warm to cooler color hue in the 4000 kelvin and above. This is very important when trying to properly light a room with color ranging from different sides of the color spectrum. Most churches have uses for dimming capability. If this is so, purchase dimmable fluorescent sub compact lamps. If I know the scope of the room, I can recommend the proper lamp. Jim Lehman 1-800-362-8155