Film-Tech Forum ARCHIVE: energy efficient dimmable bulbs

This is topic energy efficient dimmable bulbs in forum Ground Level at Film-Tech Forum ARCHIVE.

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Posted by Frank Cox (Member # 6258) on 08-12-2011, 12:37 AM:

My auditorium has a half-dozen floodlight receptacles on the ceiling and walls that are attached to a Kelmar automatic dimmer.

With new standards for energy efficiency, the standard incandescent floodlight is apparently going to be an endangered species within the next few years. Therefore, my question is, what is or will be a reasonable substitute for those things in a theatre auditorium?

I bought one "dimmable" CFL floodlight the other day to experiment with and found that while you can dim it a bit, after a certain point it starts to flicker and flash instead of dimming, so you can't crank it down to the point that you really want it while the show is on. It's not infinitely dimmable like an incandescent bulb is.

Posted by Scott Norwood (Member # 30) on 08-12-2011, 09:05 AM:

No need to worry much about this. PAR-type (reflector) incandescent bulbs will still be available, as will traffic-light bulbs (which work fine and last longer than normal bulbs) and rough-service bulbs. Halogen bulbs are another option, although they have higher heat output than standard incandescents, which some fixtures may not be able to tolerate.

If you are using standard A-type bulbs, you can replace them with one of the other types or, if you have the space, stockpile them.

CFL light quality is generally pretty bad, and some CFLs can actually be dangerous if connected to a dimmer circuit. They are good for exit stairways and other areas where the light will be turned on 24/7 and where long life and efficiency are more important than aesthetics, but not for lobbies, bathrooms, or auditoria.

Posted by Paul Mayer (Member # 355) on 08-12-2011, 09:30 AM:

Dimmable LEDs seem to work much better than CFLs from what I've seen so far - they certainly dim better than CFLs and give similar operating lifetimes and electrical cost savings. But boy are they expensive.

Posted by Randy Stankey (Member # 64) on 08-12-2011, 09:38 AM:

We have mostly biax fluorescent fixtures in our lobby and the few incandescent fixtures we have are now changed over to CFL or LED. While none of these dim, they still work well and it's a good thing we don't have to get out the Genie Lift or the ladders to change them nearly as often.

However, inside the auditorium, we are still using nearly all incandescent because 99% of the house lights must dim. I think only the exit signs and things like that are different. I think the exit signs are LED. I'm not sure because campus maintenance is in charge of those lights. I am responsible for everything else.

The high, ceiling lights are all halogen. The chandeliers are 40 w. candelabra base. The side lights and the aisle lights are regular 100 w. light bulbs.

It would be nice to change some of those over to fluorescent or LED so I wouldn't have to climb up into the catwalks or use the lift or ladder to change them so often. It's a frickin' pain in the ass when you have to climb up 50 feet and hang yourself half way off a ledge to reach a fixture.

I would like to kill the architect who designed this place, sometimes, but he already died about 5 years ago. (Good riddance! [Wink]

)

Posted by Bill Enos (Member # 440) on 08-12-2011, 10:17 AM:

Tried CFLs on both electronic and resistance dimmers, don't work well enough on either to use. CFLs don't come until nearly full power is applied so there is no fade in at all. The so called dimmable CFLS will dim to slightly more than half brightness and blink off. Either way they are of no use in theatrical applications.

Incandescent bulbs that are labeled halogen will continue to be available, as will regular bulbs 25 watt and below, colored bulbs will also continue along with candelabra and other "specialty" bulbs.

Posted by Scott Norwood (Member # 30) on 08-12-2011, 12:26 PM:

Randy--get the traffic-light bulbs to replace the regular incandescents. They provide less light per watt, but last significantly longer than standard bulbs. Alternatively, you could put in 130v bulbs, which give a slightly yellower light, but which also last longer than regular bulbs.

Posted by Louis Bornwasser (Member # 3063) on 08-12-2011, 09:14 PM:

As Bill said: only the larger bulbs are going away. Smaller bulbs, specialty, and special purpose bulbs are NOT on the extermination list. Louis

Posted by Gordon McLeod (Member # 33) on 08-13-2011, 10:49 AM:

I have had good luck with some LED products but again many use a small switch mode in there base so they cannot be dimmed
A caution on halogens if on a dimmer they often blacken if the operating temp is too low (namely running long periods at low levels) and the halogen cycle stops
Also the sockets in fixtures often have issues with the heat

Posted by William Schmidt (Member # 6395) on 09-19-2011, 11:29 PM:

I just this summer switched my auditorium over to CCFLs from Litetronics. They dim smoothly with my Kelmar dimmer down to 3-4% then go out. My show level is 0% so I have had no flicker issues. On the fade up they do blink on but not brightly enough to be jarring then fade up to my end titles level. They also make them in different color temps. The 2250K has just the nice rosy glow I want. Overall I am very happy.

Posted by Monte L Fullmer (Member # 2797) on 09-20-2011, 03:05 AM:

Ya, we switched over to these little guys in half of our houses that have wall sconce fixtures...

I'll never be changing out bulbs again the way these things will last!

...I have them running 80% on full bright, and they do dim down quite nicely, but have to really watch the dim settings in your dimmer pack (we have the Luminary 16-4 packs and I can really get the levels real good), for they will blink if the settings are just a tad too low.

What I don't get, in each package there is this little plastic shield like thing that looks that it goes with the base of the bulb....They seem to work without this shield that just seems to drop in the socket before screwing in the bulb in the socket.

-Monte