MAGNET NOISE DAMPENER - Banging House Ductwork

MAGNET NOISE DAMPENER House heating and cooling duct work banging

New house has new glitches to solve.

Our ductwork is banging when the heating and cooling system turns on and off. I believe the air pressure from the blower moves the metal out and then it slams back in place – making a banging noise. Every house I have lived in - has done this. I went on line to get solutions. There were more than a few ideas, but they seemed more involved than I was willing to put into at this time.

I came up with using a sheet magnet to stick to the metal section of ductwork that bangs to reduce the noise.

Supplies

Material

Magnetic Sheets estimated size of 8 inch X 15 inch (they come in different sizes)

Strong Magnetic Vent Covers - Vinyl Magnet for Air Registers

Optional

Heavy duty craft scissors

Step 1:

Strong Magnetic Vent Covers - Thick Magnet for Air Registers – they are used for RV, Home HVAC, AC, and Furnace Vents - These Magnetic Sheets can be found in the estimated size of 8 inch X 15 inch. Well I am sure magnetic sheets can be found in other sizes but I find that these are easy to find.

The magnets I purchased was a multi package also these are thin enough to be able to cut and trim to the size as needed - with heavy craft scissors.

Step 2: Find the Banging Duct Work Section

Just sitting in the house I could hear the banging. While the furnace was off for a little while, I went downstairs. I had my wife turn on the system with the thermostat. (in hindsight I should of just had her turn the fan on and off). I was able to locate the section of ductwork that was banging. It actually turned out to be two sections.

Step 3: Place the Magnet on the Metal Ductwork

I am fortunate to have a basement and my banging sections were easily found and also easy to get at. (please note usually when I tackle a project it is in the last place I look and the hardest place to get at). Anyway I started out by placing the magnets in the center of the ductwork. I found it had better dampening affect by putting them slightly offset. So a little trial and error. I used what I had and a greater sound dampening probably could be obtained by larger magnets.