What is the minimum required distance for return air ducts from draft hoods and vent outlets?

The minimum required distance for return air ducts from draft hoods and vent outlets is typically 10 feet. This requirement is in place to ensure that the return air ducts do not draw in combustion gases or exhaust from appliances, which could lead to the circulation of harmful or contaminated air within the building. By maintaining this distance, the system prevents potential backdraft, reduces the risk of introducing pollutants into the indoor environment, and ensures efficient operation of heating, ventilation, and air conditioning systems.

This distance is established based on best practices in HVAC design to enhance safety and air quality. Duct systems are designed to maintain optimal airflow and temperature regulation, so adhering to code requirements pertaining to distances from sources of combustion gases is fundamental for both performance and safety. Other options, while they might seem plausible, do not comply with standard codes and regulations set forth by authorities in HVAC design.