Pops, Bangs and Whistles: Dealing with HVAC Ductwork Noise

Pops, Bangs and Whistles: Dealing with HVAC Ductwork Noise

There are few things as disturbing as being woken up from a deep sleep because of HVAC duct noises. Here are some simple ways to prevent and deal with the pops, bangs, and whistles that are keeping you up at night.

Is It Expansion And Contraction?

One of the most common causes of banging in a furnace is the expansion and contraction of the ducts themselves. When you turn the system on or off, you’re running hot or cold air through it. If that temperature is wildly different from the ambient air, you may hear noises that resemble large banging inside the system.

While this is normal, it’s not desirable. One way to stop this from happening is to wrap the ductwork in insulation, seal it up better, or call these HVAC contractors to help you replace the ductwork with a thicker gauge of steel.

Check The Dampers

Check the dampers on the supply side of the ductwork. If you have a lot of dampers closed, it could create your banging noises at night. Open one damper at a time and see how that affects the noise. If you notice an improvement, keep opening dampers until the noise has completely dissipated.

Add a Filter

Adding a filter can help dampen the noise you hear. These filters are non-pleated inside the ductwork. Attach them with metal braces and see how that affects the noise.

Adjust The Actuator

Inside your ductwork is an actuator. Adjust it up or down to change the banging. These adjustments can cause the noise to stop altogether, but if this doesn’t work or you’re unsure how to manipulate them, you’ll need to contact an HVAC technician for assistance.

Clean The Ducts

Clean the ducting. Sometimes, excess dirt or grime will get trapped inside the ducts and cause the air to flow improperly through them. This can also be an unusual cause of knocking or banging noises. You’ll probably have to hire a professional for this job though.

He will come and run a “snake” through the ductwork to capture any debris that may be trapped inside there. Then, he will flush it out one side of your duct system. Alternatively, he may send a special vacuum into the ducting to clean out the system.

Clean The Fan

Cleaning the fan is a simple solution that might also work well for you. There’s a fan inside the ductwork that moves air for both the air conditioning and the heater. Make sure If this worked for you, remember it. You may have to do this multiple times throughout the year. It doesn’t mean that there’s something wrong with your system. On the contrary, it might work so well, that’s it’s accumulating a lot of dust and dirt.

Add More Insulation

This can reduce or stop the banging noises in your HVAC system. Simply add insulation to the entire run of ductwork that’s in your basement or attic. Make sure you’re using insulation that’s specially made for them though.

Monica A. Phelps works as a home improvement associate. She enjoys sharing her experiences by posting on the web. Her articles are available on many home improvement and DIY websites.