What Is Causing Noises in the Air Ducts?

You’ve probably heard noises coming from your air ducts, which could be anything from a mild creaking to loud banging sounds. While some are nothing to be worried about, others may indicate a problem that requires the attention of an HVAC professional. In today’s post, All Seasons Inc. discusses the reasons why your air ducts are making noise.

Thermal Expansion and Contraction

Air ducts are typically made of sheet metal, which are subject to expansion and contraction from changes in temperature. When you turn on your HVAC system for the first time in the season, the air ducts expand or contract, creating cracking and popping sounds, particularly near the seams. Usually, such noises would cease as soon as the air ducts have acclimated to indoor temperatures. If they’re persistent, you have to have it inspected by an HVAC professional.

Obstruction in the Air Ducts

Sometimes, noise in the ducts can be a result of debris or pests blocking the airflow within. These obstructions can create unusual sounds as the air tries to move around them. Pests and contaminants usually make their way into the air ducts through gaps, which may be caused by corrosion, damage or improper installation. This emphasizes the need to have your air ducts cleaned and resealed by an HVAC professional every five years or so — clean air ducts are less prone to noises and will help maintain indoor air quality.

Differences in Air Pressure

Sometimes the air ducts would be mismatched with the furnace or air conditioner’s capacity, causing differences in air pressure that results in popping and banging, or whistling and rattling. A mismatch can happen if the air conditioner or furnace isn’t sized in proportion to the air ducts, which can happen when an inexperienced individual chooses a replacement system. There is no single fix to this issue because of the factors involved — it’s best to have your system diagnosed by an HVAC professional if it is a persistent problem.

If you’re experiencing noisy air ducts, our HVAC professionals at All Seasons Inc. can help you regain peace in your home. Give us a call at (253) 879-9144 or fill out our contact form to schedule a consultation. We serve communities in Puyallup and Tacoma, WA.