Banging and rattling noises coming from the HVAC ductwork can be alarming and annoying, especially when you are trying to get some quality sleep. This can be unnerving as well because you do not have any idea what is happening with your HVAC system. If you have issues with noises in your ductwork, find out what causes them and how to address them.
Why Does My HVAC Ductwork Make A Banging Noise?
Your ductwork distributes air throughout the house. The quick movement of air within the ducts can sometimes create noise. Sometimes, the intensity of the sound can be startling. Some homes may also have ductwork that is made up of sheet metal and this material is notorious for being the noisiest. In some cases, the banging noise is not something to be worried about. However, loud noises and other sounds may point to a problem.
Common Causes For Noisy Ducts
There are several reasons why air ducts become noisy. Here’s a closer look at some of them:
HVAC Ductwork Makes A Popping, Ticking, & Banging Sound
Banging, popping, and ticking noises are fairly common in many homes. These sounds are produced when duct walls move or shift because of changes in the temperature and pressure.
When hot air travels through the ductwork, the heat causes the metal to expand. When it’s cold air that is being distributed through the ducts, the metal contracts. These movements produce noise.
To fix: To keep your ductwork quiet, ask your local HVAC technician about available options to upgrade your duct network.
Rattling HVAC Ductwork
A rattling noise sounds like there is something that shakes such as a small piece of metal against other metals. This sound is usually the result of the loosening of a portion of the ductwork. If the HVAC system is not being used, you will not hear this rattling noise. However, once the system is running and the air is moving through the ductwork, the rattling sound can be heard.
To fix: Call an HVAC technician to find the loose part and have it fixed. Do not attempt this repair yourself if you have no experience or skills since you could do more damage to the ductwork.
Clanging HVAC Duct Sound
A clanging sound in the ductwork is usually due to a loose vent damper. Once it has come off and air flows through, the damper will open and close, causing a loud noise.
To fix: Call a professional technician to get the vent damper repaired or replaced.
How To Quiet Down Noisy HVAC Ducts
Thankfully, you do not have to suffer through the day or night because of noisy ducts. There are ways to fix the issue. These include:
HVAC Vent Damper Upgrade
Getting your vent damper replaced is the best solution to completely stop that banging or clanging noise caused by a loosened old damper. Consider upgrading to a spring-loaded backdraft damper. This is designed to keep itself shut until it needs to open to allow air through. Dampers are very affordable and can help you keep your ductwork quiet.
Change The HVAC Air Filter
Ductwork is the tunnel through which heated or cooled air passes. With good airflow, your ductwork will be relatively quiet. However, dirt and debris that accumulate in the filter can restrict proper airflow. This will result in strange noises in the ducts.
Clogged air filters can also affect the efficiency of the HVAC system. Since dirt acts as an obstacle for air, the system has to work harder just to push a sufficient amount of air through. To do this, the unit has to consume more energy, which increases your energy cost unnecessarily.
As a preventive step, make sure that the HVAC air filter is checked periodically (at least once a month) and replace when necessary. The HVAC air filter replacement schedule will depend on the environment. A dirty HVAC filter will need to be replaced to keep your HVAC system working properly.
Consistent HVAC Maintenance
Your HVAC system will not only remain efficient and reliable but also cost-effective if it undergoes regular maintenance. When maintenance is consistent, your HVAC system receives the attention and service it needs. The HVAC technician can inspect the unit and identify problems early on. They can then apply the best solution to prevent further issues down the line, many of which can be costly.
Furthermore, consistent maintenance also ensures that your system is working well. You get to enjoy good performance every time and rely on the system to provide you with a comfortable indoor environment throughout the year. Better yet, you do not have to deal with those annoying banging noises.
HVAC Static Pressure Issues
Static pressure is another factor that causes noise in the ductwork. If the pressure within the ducts is a little too high for the HVAC system to handle, expect the ducts to pop or bang. High static pressure in the ductwork means that the system is moving more air that the ductwork cannot accommodate. The pressure causes the ducts to expand, which results in the banging and popping sound. When the pressure decreases, the ductwork will contract, which causes more noise.
HVAC Duct Silencer
Round ducts produce more noise than rectangular ones, so if this is an issue, consider having a duct silencer installed. This acts as a muffler for ducts and works very well, too. Duct silencers are built with double walls and insulation that helps reduce vibration and noise. Duct silencers are positioned close to the parts of the system that cause the most noise. So when the HVAC is running, any noise it produces is significantly reduced.
Variable Speed Blower
If your home uses a single-speed blower in your HVAC system to handle the heating and cooling, the ductwork will expand and contract as a result of changing temperatures. Consider having a variable-speed blower installed instead.
Variable-speed blowers can adjust the airspeed without impacting the temperature. They also prevent extremely high or cold temperatures, so the ductwork does not contract or expand. Variable-speed blowers are also energy-efficient, so you do not need to worry about higher energy consumption.
You could muffle HVAC noise effectively using insulation. You could do this as a weekend project or have a professional install it for you. The noise will still be present but it will not be as loud.
If your HVAC system remains noisy and requires costly maintenance and modifications, why not look at the benefits that a ductless mini-split system can offer?
Ductless systems, as their name implies, do not require ductwork to distribute air throughout the house. Many ductless models are energy-efficient and you could even choose to have a multi-zone installed. This will allow you to create different temperature settings throughout the house. Each of the areas or zones can be programmed to have a different temperature independent of other areas.
You could, for example, set a higher temperature in the bedrooms and lower temperatures in the kitchen at certain times of the day. Zoned ductless systems also allow you to turn off the heating or cooling in an unused room while keeping occupied rooms warm or cool. You not only enjoy better savings but also rest easy with the quieter operation of these models.
HVAC technology has improved immensely in the last 10 years. While some people may still consider banging and clanging noises in the ductwork as normal, it does not mean that you have to suffer through the inconvenience they bring. There are solutions available to you that allow you to enjoy high-efficiency and relatively quiet comfort.