3 Reasons Your Air Vents Are Noisy when Your Heat Turns On

Noisy Vent

Many home and business owners become frustrated with one of the most popular general HVAC service questions: What causes noisy air vents? For some, this is a mere annoyance. For others, it can make it impossible to live or work in the building. Most explanations for this noise revolve around the fact that too much air is flowing through the HVAC system. But why is this the case? There are three common reasons:

1. Inadequate Ductwork

Not all ductwork is the same. As common sense would indicate, larger and wider ductwork can handle more air flow. When ductwork is too narrow to effectively provide the necessary amount of warm or cool air to a building, the speed of the airflow usually increases to compensate. When the air is moving faster than the ductwork can take, it can create unusual noises.

Ductwork can be inadequate for multiple reasons, including a miscalculation during installation, poor design or the installation of a more powerful HVAC unit that provides more air to the building than the original ductwork can handle.

2. Blocked Air Return Vents

Another reason for too much airflow through an HVAC system is when the air return vents are unable to deliver the required amount of air. This can be because there aren’t enough air return vents, but more often, it’s due to closed or blocked return vents. One of the quickest and easiest fixes to noisy air vents is simply unblocking them.

3. Not Enough Air Supply Vents

When there aren’t enough air supply vents, what little air the HVAC system can pull from the building’s indoor areas must flow through one or two air supply vents at high speed. Because there aren’t enough vents, air flow has no choice but to move faster in the existing air supply vents. This faster-moving air can be the source of strange or loud sounds coming from the HVAC’s air vents.

To get answers to any additional general HVAC service questions you may have, don’t hesitate to contact our knowledgeable HVAC technicians and staff at McCall’s Supply, Inc.