# Dimmer causes lights to hum



## MatrixDweller (Jul 24, 2007)

I recently hooked up my Lutron Grafik Eye and noticed that when the lights are dimmed the bulbs make a high pitched hum. I read that rough service bulbs will not do this, but they normally don't come in the PAR format. 

Does anyone know of some good bulbs that are resistant to humming?


----------



## tonyvdb (Sep 5, 2007)

If you can find a Halogen par bulb that should also work as they are built differently. The "hum" you hear is the filament vibrating as its not hot enough to sit in the holder properly.


----------



## MatrixDweller (Jul 24, 2007)

Problem solved. I exchanged the BR30 bulbs for PAR20 and the humming is now gone. Thanks for the advice tonyvdb. I couldn't find any 50-75W PAR30 bulbs at my local ****** Tire or else I would have got those instead. The PAR20 has a narrower beam, but I think that might be better in my room anyway because I have sconces to pick up the slack. The light from the PAR20's is nicer too I think. More of a pure white than the BR bulb. 

I'm hoping that LED technology becomes cheaper so I can eventually replace these 50W bulbs with more energy efficient ones. I've seen them in the 4 or 5 Watt range. They're too expensive and not refined enough to switch my whole house over. I have a friend who switched his whole house to compact fluorescents. I'm not keen on the colour temp they give off. He worked it out in spreadsheet that he'd save a couple hundred bucks over a couple years.


----------



## Bent (May 24, 2006)

I'm not so sure you can dim LED type lights, and I'll almost 100% garrantee that 
90% of all CFL's can't be dimmed.

In the winter, any energy saved by using CFL's will be offset by the cost of your furnace running to make up the heat.

Watts is always Watts.


----------



## MatrixDweller (Jul 24, 2007)

LEDs are dimmable as they just use stepped down AC converted to DC. CFLs on the other hand have a ballast that can't normally be dimmed unless built expressedly to have that ability. Dimmable CFL I've seen are often 2 to 3 times the price of regular CFLs.

As for my furnace having to work extra...I have a furnace that is much more efficient at producing heat than an electric light bulb. I think the rating on my furnace is 94% AFUE. If you were to give a similar rating (not that it is really the same) on a light bulb it would probably be in the 25% or below range. A similar comparison would be an electric furnace, which is a more efficient heat generator, compared with my gas furnace. The electric furnace would end up costing twice as much to operate.


----------



## Bent (May 24, 2006)

sorry - I was assuming an electric furnace.
(I work for the power company)


----------



## steverc (Jan 5, 2008)

LEDs are dimmable but most dimmers have a minimum wattage that will work without flickering. I had to use incandescent rope lights under my steps instead of LED rope lights for that reason. Lucky for me I read the manual before I bought the lights.:nerd:


----------



## Kevin_Wadsworth (Apr 25, 2007)

MatrixDweller said:


> Dimmable CFL I've seen are often 2 to 3 times the price of regular CFLs.


For the record, I bought some expensive dimmable CFL's to try out in my basement. They still didn't work. so, I reassigned them to areas of the house that don't use dimers and bought incandescents for the basement.


----------

