November 20, 2022

When your home has a forced-air furnace system, the boxes between the outgoing and intake ducts are called the supply and return plenums. Along with assisting the furnace with distributing and collecting air, the plenums also serve two additional and important functions.

1. Reduce the Noise Made by Air Flowing Through the Ducts

One function served by both the supply and return plenums is noise reduction. In a forced-air system, the air coming from and returning to the furnace is usually pretty loud. Without the buffering effect of the supply and return plenums, you would hear the whooshing of air throughout the house.

When one of the plenums is damaged, a loud noise is one of the first signs that something is wrong. This noise is often accompanied by a rattling sound. When you hear these noises, it means air is being lost until the plenum is repaired.

2. Clean the Dirty Air Before It Enters the Furnace

The return plenum serves another critical purpose. It is the furnace’s first line of defense against dirt and dust. It partially cleans the air before it flows through the filter, which helps to significantly reduce the dirt that contaminates the furnace’s interior.

Without a return plenum, too much dust and dirt would enter the furnace. When this happens, airflow is blocked, and the furnace must work harder to force the air through the system. If you notice the filter getting dirty faster than usual and dust accumulating inside the furnace, have the return plenum and the entire furnace assessed by a professional.

At Hammack Service Company, Inc., we specialize in Heating and AC repair, installation, and maintenance in Richardson, Texas and the surrounding communities. If you hear loud noises coming from your supply or return plenums, contact us to check them out. If your home seems unusually dusty or you notice dust in your furnace, that’s another reason to give us a call. Contact Hammack Service Company, Inc. today to get your HVAC on track!

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