What is the nominal diameter in inches for clothes dryer exhaust ducts?

The nominal diameter for clothes dryer exhaust ducts is typically 4 inches. This size is standardized to ensure proper airflow and ventilation, allowing the dryer to vent moist air effectively while preventing lint buildup, which can pose a fire hazard. A 4-inch diameter works well for most residential dryers and meets the requirements set by building codes and appliance manufacturers.

Understanding the importance of this specification is crucial for home inspectors, as using ducts with a different diameter can lead to inefficient dryer operation, potential vent clogging, and increased fire risk. Utilizing the correct size also ensures that dryer appliances function within their intended parameters for safety and efficiency.