If the noise is just air movement, you will want to line the duct with absorbing material, or create a baffle. If you go this route, do not use materials that can become airborne such as fiberglass. Closed cell foam would be the safest.
If you notice an AC vent rattling noise or clanking sound, it could mean that your metal duct joints are loose or disconnected. Use metal tape to reconnect the joints, then call a local AC repair pro for a long-term fix.
Banging noises are a sign of air pressure problems in your ducts. A whistling sound, on the other hand, might indicate a blockage or gap somewhere in the system, forcing air to squeeze through. Rattling can mean loose parts inside your air ducts that are knocking around.
A correct installation, e.g. avoiding the use of excessive lengths of ducting, crushed ducts, or improperly sealed ducts that cause leaks or the build-up of pressure (either of which will require your ventilation unit to have to work harder, in turn generating excess noise).
To combat this problem, wrap your ducts with acoustical insulation, or replace the sections nearest the air grilles and vents with lined duct sections. Another solution is to replace your regular metal grilles with lined versions, or to ask your landlord about adding sound attenuators to the ducts.
Damping, also known as sound deadening, can reduce noise in ventilation systems. Damping involves coating or sticking a viscoelastic or bituminous type of material to thin, vibrating surfaces. The coating reduces the surface's tendency to amplify vibrations and radiate noise.
The duct silencers enable maintaining proper acoustic parameters in the rooms – even reducing noise in the rooms which require a high degree of acoustic comforts, such as e.g. sleeping rooms or reading rooms. The noise can be generated not only by the flow of air through the ducts.
In many instances, the whistling noise is produced by vents that aren't properly attached or the incorrect size. In the winter months, the whistling noise may be reduced by slowing down the system's fan speed. This will slow the speed of air moving through the system and may help eliminate the issue.
Experts advise having your air ducts cleaned every 2 to 3 years to prevent many maintenance and health problems before they start. However, homes with pets or children with allergies should have their air ducts professionally cleaned more frequently than the recommended average.
Installing duct silencers or wrapping your system's compressors in soundproof blankets can significantly reduce noise. Silencers absorb sound, and soundproof blankets wrap around the equipment to minimize vibrations.
This surprisingly high amount of sound leakage from such small holes and cracks can be readily treated and eliminated with the use of acoustical caulk. Latex-based acoustical caulking provides an effective sound barrier because it remains soft and pliable for its lifespan and will not harden and crack.
It is best to place the Duct Silencer within 2 - 4 feet of the blower / ventilator for maximum noise reduction.
The State of California requires that vehicles have an adequately working muffler, which means you cannot remove or make adjustments to your muffler that intentionally increase the noise of the vehicle.
Vent silencers are mounted after relief valves to reduce noise pollution to a bearable level. Relief valves are commonly used in i.e. power stations, as well as chemical, petrochemical and other similar plants.
The most ideal solution is to use separate ducts to feed each room and if that is not possible then at least position the ducts as far away from each other as possible. A suitable acoustic foam duct lining material is the fire retardent Duct Foam. It's best not to use fibreglass type materials due to fibre migration.
Adjust or Upgrade the Dampers
Dampers help control the flow of air throughout your duct system. Sometimes a banging sound is caused by vent dampers that blow open and slam shut. You can fix the problem by adjusting the actuator in the damper, which can reduce or stop the noise.
Baking soda is known for its odor-absorbing properties. Vinegar Solution: Create a solution of vinegar and water and spray it into the HVAC vents. Vinegar can help neutralize odor. Essential Oils: Place a few drops of essential oils on the air filters or a cotton ball and put it near the ventilation system.
The materials and construction methods used in your home play a significant role in sound transmission. Thin walls, poorly insulated windows, and lightweight materials can allow external sounds to penetrate easily. Homes located in densely populated areas or near busy streets are more susceptible to these issues.