Central Air Noise

Old 08-04-08, 06:42 AM
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Central Air Noise

I have a question. Any advice or suggestions would be greatly appreciated. Whenever I turn on my a/c a whistling type noise can be heard in my smaller bedroom. The noise is continously until the a/c is off. It is very irritable. The room that the noise is coming from is also by the attic, but the noise is definitely coming from the room. No other room in the house does that, its just that one room and as soon as I step out of that room I can not hear the sound. My vents are not on the floor, they are on the walls near the top of the ceiling. The noise is coming from inside my wall, it seems. What could be the problem as well as a solution.

Thanks a bunch!!!!!!

Last edited by tiaglam; 08-04-08 at 08:45 AM.
Old 08-04-08, 08:17 AM
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Very likely the vent cover for the A/C in that room or possibly a small leak in the duct near the vent. I had a similar noise once, and just sealing around the screw holes made it stop.

Try taking the vent cover off, see if the noise stops. You don't need to wait for the A/C to kick on, just put the fan to the "on" position. If it stops, partially block the airflow from the vent with a magazine or similar to simulate a vent. If you hear the noise, look into the duct for any holes or cracks.

If you don't hear the noise with it off and trying these tests, its probably caused by air passing over the vanes in the vent or leaking past the edges.

If it has adjustable louvers, try changing the position slightly. If it does, and that doesn't help, you may want to try a non adjustable vent cover. Less stuff in the way of the airflow to cause noise.

Some thin foam self adhesive weatherstrip around the flange of the vent might help also.

Sorry just thought of another way to listen. Use a papertowel tube or similar, held to your ear, to listen all around the edge of the vent, might find it right off. Try to keep it out of the airflow, just up close to the edges.

Oh, all this is based on you just having the vent (blows out) in there, not a return (sucks in). If you do have a return, might check that first. Esp if it has a filter in it!
Hope this helps..

Last edited by Gunguy45; 08-04-08 at 08:21 AM. Reason: other option

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