What Causes Duct Bursts and Loud Popping Noises in Air Ducts?

Duct bursts and loud popping noises in air ducts can be caused by a variety of factors, and it’s important to understand the underlying reasons to address the issue effectively.

Pressure Differences

Pressure Differences Between Supply and Return Ducts

One of the main causes for these loud noises is the difference in pressure between the supply and return ducts in your HVAC system. The supply ducts carry the conditioned air from the furnace or air conditioner, while the return ducts bring the air back to the system. When there is a significant pressure difference between these two, it can cause the ducts to expand and contract, leading to the popping and banging sounds.
Temperature Changes

Expansion and Contraction Due to Temperature Variations

Another common cause of duct noises is the expansion and contraction of the ductwork due to changes in temperature. As the air in the ducts heats up or cools down, the metal or other materials used in the ductwork will expand and contract, resulting in the popping and banging sounds. This is particularly common in older homes or buildings where the ductwork may not be properly insulated or sealed.

Addressing these issues can help reduce the loud noises and prevent potential duct bursts. Proper maintenance, insulation, and sealing of the ductwork can help mitigate the pressure differences and temperature-related expansion and contraction, leading to a quieter and more efficient HVAC system.