When you install a new HVAC system, it is important to carefully consider which air distribution system design you want to use, as there are a variety to choose from, and each one has its own pros and cons.

If you are unfamiliar with HVAC design, you may feel confused or overwhelmed by this process. You may find yourself asking questions like “What is the difference between the perimeter loop and radial duct system?”

Fortunately, as HVAC duct manufacturers, we at Spiral Mfg. are well qualified to answer this particular query.

The perimeter loop system and the radial system are two fairly common HVAC duct configurations. While they do have some similarities, their differences are pronounced enough to make them each best suited for a distinct range of applications.

The Radial Duct System
The radial duct system is far more common than the perimeter loop duct system. It is made up of a central plenum (the air-distribution box that is directly connected to the heating and/or cooling source) and a number of individual ducts. The individual ducts are attached to the plenum, and form a radial pattern. Each duct delivers air to an individual outlet.

Because the duct runs are short and direct, radial duct systems are great for maximizing air flow. They are often used in small buildings, single-story homes, attics, and crawl spaces.

(Cold Storage: A View of Energy Efficient Technologies and Practices - Scientific Figure on ResearchGate. Available from: https://www.researchgate.net/figure/Various-supply-duct-configurations_fig6_264472530 [accessed 22 Oct, 2021])

(Cold Storage: A View of Energy Efficient Technologies and Practices – Scientific Figure on ResearchGate. Available from: https://www.researchgate.net/figure/Various-supply-duct-configurations_fig6_264472530 [accessed 22 Oct, 2021])

The Perimeter Loop Duct System
A perimeter loop duct system consists of a central plenum and a ductwork loop that circles the perimeter of the building. A series of ducts radiate from the central plenum and connect to the loop. Conditioned air travels from the plenum to the loop, which delivers it to different parts of the building.

Perimeter loop duct systems are more difficult to design and install than radial duct systems, but generally perform better than the latter in large buildings and cold climates.

(Cold Storage: A View of Energy Efficient Technologies and Practices - Scientific Figure on ResearchGate. Available from: https://www.researchgate.net/figure/Various-supply-duct-configurations_fig6_264472530 [accessed 22 Oct, 2021])

(Cold Storage: A View of Energy Efficient Technologies and Practices – Scientific Figure on ResearchGate. Available from: https://www.researchgate.net/figure/Various-supply-duct-configurations_fig6_264472530 [accessed 22 Oct, 2021])

Spiral Manufacturing: Premier HVAC Duct Manufacturers
If you would like to learn more about HVAC duct design, contact Spiral Mfg. at 763-755-7677 or send an email to info@spiralmfg.com. We pride ourselves on being leaders among HVAC duct manufacturers, and look forward to helping you meet your HVAC needs.