humming vent

[Scoot]

My cold air return vents are making a humming noise. If I hold my hand over them, it stops the vibrations and makes the humming stop. Given that I can't reach all of the vents at once and that I have better things to do, I need a suggestion as to how to fix it. Any suggestions?

[minneman]

have you tried tightening the screws that are holding the registers to the wall?

Seems odd that they would vibrate at all. where do the vibes come from? From air passing threw them seems unlikely..?

[MNice]

Usually its just the vanes of the register vibrating slightly. Tweak them with a needle nose, or remove one of the vanes completely.

[fivebucks]

But are they humming out of tune?

[sparcebag]

Mnice I notice mechanical inspect.Coult it be he has a over sized,furnace? blower motor? sounds to me like hes a lot of air passing,Or maybe a cloged fresh air (exterior air)vent?

[MNice]

Very good point. AC's are usually set for blower to be on high speed, which could cause the humming. Once in a while you would run across a bad register and any amount of air would make it hum. As far as the clogged outdoor air, I would doubt it. Back in the day it would be normal to run the combustion air into the return air system, but newer furnaces are very touchy about that now. To cover their product, most furnace manufactures limit the return air temp to 55* or 60* min temperature.

[Scoot]

Thanks fellas. I originally tweaked a vane in each section of the vent, but it didn't work. I went back and tweaked three vanes in each section and it took care of it.