The answer to 'air duct sealing making noise' is that air duct sealing can sometimes cause noises like whistling, rattling, or humming. This is often due to improper installation or the use of the wrong type of sealing material. Duct sealing is an important step in HVAC system maintenance, but it needs to be done correctly to avoid creating new problems.
If you've recently had your air ducts sealed and are now hearing strange noises, the first step is to inspect the sealing work. Look for any gaps, cracks, or loose connections in the ductwork. Improperly sealed joints or the use of the wrong sealant can cause air to escape and create whistling or rattling sounds. In some cases, the duct sealing material itself may be vibrating and causing a humming noise.