Which requirement must be fulfilled for duct piping in pressure-side locations?

In the context of duct piping in pressure-side locations, the requirement that it must be durable and meet size specifications is crucial for effective performance and safety. Pressure-side ducts are subject to varying internal pressures and airflow velocities, which necessitate robust materials that can withstand these conditions without failure. Durability ensures that the duct can operate effectively over time without compromising the system's integrity.

Additionally, size specifications are critical to ensure adequate airflow, prevent pressure drops, and maintain efficiency within the heating, ventilation, and air conditioning (HVAC) systems. Proper sizing affects not just the performance but also the energy consumption, as ducts that are too small can restrict airflow, causing systems to work harder and potentially leading to increased operational costs and failures.

Insulation, while important in certain contexts for energy efficiency and condensation prevention, is not a primary requirement for pressure-side duct piping. Similarly, the choice of materials and installation practices, although significant, defer more to industry standards and safety regulations rather than specific durability and sizing requirements. The emphasis on durability and conformity to size specifications directly addresses the performance and operational criteria essential for pressure-side duct systems.