We recently added new office space in the basement of our home. I bought three fluorescent fixtures 48" with 4 T-8 32 watt bulbs in each one. These were Home Depot's "Best" quality with electronic ballasts and were supposed to be "noise free." Well, the first thing I noticed when they were switched on, was the annoying "hum!" I thought electronic ballasts were not supposed to make noise. Does anyone know why they might produce this annoying hum?

Thanks in advance

They may be a hybrid ballast. Which means it is a combination magnetic coil and electronics. These may hum as they still have magnetic coil in them.

But if it is a true electronic ballast, the noise must be the high frequency hum or buzz, that is getting amplified by the metal housing of the fixture.

Does the housing have any screws or clips that can be tightened?

I will tell you, I have hundreds of fluorescent light fixtures installed and never a peep.

I believe HD sells Lithonia fixtures, which are typical, popular, and I use them also. I don't get them from HD, but through distributors, but they all should be coming from the same factory.

Can you provide the model number of the fixture and the ballast?

Thanks for the reply tk...

Yes, they are Lithonia fixtures. I don't have the boxes anymore but inside the lamp cover the sticker says "Lithonia 987213 model LB4 32 120 1/4 GESB" The Ballast says "AcuPro Model AP-RC-432IP-120." I checked for loose screws but everything appears to be snug. It is definitely an electronic "buzz" coming from all three fixtures. They cost $54.95 each from HD. I figured for that price they ought to be decent quality. I will take them down and bring them back to the store if necessary, but it seems odd that all three fixtures are making noise.

Probably some off shore ballast and the right combination of loose housing to cause the high frequency noise to be audible.

Sure, bring them back, like I said I can't say I know what one sounds like as I have been around 1000's of new fixtures that are quiet.