When it comes to air conditioning systems, the design of the air ducts is essential for optimal performance. There are four main types of air duct designs, each with its own unique characteristics. The radial or plenum duct system is the first type. This system has the air conditioning unit and return grill located in the center of the house, with supply ducts extending outwards like the legs of a spider.
The extended and reduced distribution chamber system is the second type. As the name implies, this system has a pressure chamber that gradually reduces in size as it extends, with air ducts coming out on both sides. The extended pressure chamber system is the third type. This system also has a pressure chamber that distributes or extracts air for the air conditioning unit, but it does not reduce in size as it is extended.
The last type is the perimeter circuit system. This radial system has a supply duct that surrounds the building, rather than having multiple spider legs. In some cases, air ducts branch out from an air conditioner or heater located in the center of the building. When there is a change in air direction in a duct, it takes approximately 24 inches for airflow to restore its pattern.
In multi-room systems, there are return entrances in each room (or almost every room) that receive air conditioning. No matter what type of air duct design you choose for your home or business, it's important to understand how each one works and how it can affect your overall system performance.
