What type of fasteners should not be used to connect dryer ducts to prevent obstructing airflow?

The correct answer is based on the functionality and design of dryer ducts. Sheet metal screws are actually a standard choice for fastening sheet metal ductwork; they do not obstruct airflow when installed properly.

In contrast, wood screws and plastic ties are not suitable for this purpose. Wood screws can protrude into the duct, creating potential obstructions and turbulence as air flows through, which can reduce the efficiency of the dryer. Plastic ties are generally not designed to secure ductwork effectively and can allow for movement or separation under the stress of airflow, leading to potential leaks and airflow restrictions.

Zip ties, while they can be useful in some applications, similarly fail to provide a secure and permanent connection necessary for dryer ducts. They can degrade under heat exposure and may not handle the vibration from the dryer effectively.

Therefore, it’s important to use fasteners that maintain a smooth interior surface to facilitate optimal airflow, and sheet metal screws, when applied correctly, fulfill this requirement without causing obstruction.