Closed-loop piping systems offer several advantages in HVAC applications, including reduced water consumption, lower chemical treatment requirements, and decreased environmental impact. Closed-loop systems also provide better control over water quality, which can improve the overall efficiency and reliability of the HVAC system. Additionally, closed-loop systems are less prone to scaling and fouling, reducing the need for frequent cleaning and maintenance. These benefits make closed-loop systems a popular choice for many HVAC applications.