The answer to 'why is my ductwork making loud noise' is that there are several common causes, including air leaks, loose connections, and obstructions. Loud noises from the ductwork can indicate a problem that needs to be addressed to maintain proper airflow and efficiency in your HVAC system.
Some of the most common causes of noisy ductwork include: air leaks that allow air to escape, loose connections between duct sections, obstructions or blockages in the ducts, and issues with the blower fan or motor. These problems can create whistling, banging, or rattling sounds that are disruptive and may indicate a larger problem with your HVAC system.