For using stud cavities for return ducting, which condition must be met regarding temperature?

Using stud cavities for return ducting involves specific temperature limits to ensure safety and efficiency within a building's heating, ventilation, and air conditioning (HVAC) system. The correct choice sets the maximum allowable temperature at 125 degrees Fahrenheit. This limit is established to prevent potential damage to the ducting and building materials, as well as to maintain comfortable and safe indoor air quality.

Temperature limits are critical because exceeding the designated maximum can lead to issues such as thermal expansion, increased fire risk, or degradation of duct materials. A maximum temperature of 125 degrees strikes a balance between operational efficiency and safety. This condition also ensures that the materials used for the stud cavities can withstand the operational environment without compromising their structural integrity.

While other options suggest higher temperature thresholds, they exceed what is recommended for safe operation in stud cavities, increasing the risk of adverse effects on building materials and overall HVAC system efficiency. Therefore, adhering to the limit of 125 degrees is essential for maintaining a healthy and effective indoor environment.