Benefits of Spiral Round Ductwork

Spiral Round Ductwork is more Efficient than
Conventional Rectangular Ducting. 

For facilities managers, optimized facility performance is an important part of their job.  That's why many facilities are moving toward spiral round ductwork as opposed to conventional rectangular ducting. Static regained spiral round ducting can do more with less when compared to conventional rectangular ductwork: 

• Costs about 1/4 less 
• Weighs 25% less 
• Easier to install 
• Less bulky than conventional rectangular ducting in variable (VAV) or constant volume systems (SPIDA). 

Spiral round ducting can enhance the HVAC systems performance, as systems that include static regain designed spiral round ductwork use less energy, deliver air to every VAV box and create a more comfortable indoor environment for occupants and visitors. 

Take for example the leakage rate of rectangular ductwork compared to spiral round ductwork. Leakage for rectangular ductwork occurs at a much higher rate than spiral ductwork, which has a leakage rate of less than 1% (SPIDA). 

By reducing leakage, there is a significant impact on the HVAC energy efficiency and occupant comfort. The right amount of conditioned air can be directed to the intended locations within a facility, which results in better indoor air quality and a more comfortable environment for occupants. 

Another benefit of spiral round ductwork, according to the American Society of Heating, Refrigeration and Air Conditioning (ASHRAE), is the allowance of spiral round ductworks for higher uses of air velocity than compared to rectangular ductwork. Higher velocity, static regain designs are state-of-the-art for current lower installed costs VAV systems.  

Direct Digital Control (DDC) strategies can enhance the efficiency of a round ductwork system. DD/VAV controls allow for fan pressure optimization because you can identify which VAV box in the system requires the maximum static pressure and then control the fan to provide just that amount of static pressure and no more. 

This article was derived from the headline "The HVAC Factor: Spiral Round Ductwork", which appeared on September 17, 2013 in the Today's Facility Manager.