A vent connector is required unless what condition is met?

A vent connector is essential in ventilation systems to ensure proper exhaust of combustion gases from the appliance to the venting system. The correct choice indicates that a vent connector is not needed if the vent is connected directly, which means that the appliance can discharge flue gases straight into an existing or adequately designed venting system without additional piping for connection.

This allows for a more streamlined and efficient exhaust system, reducing the risk of backdrafts and ensuring proper ventilation, which is crucial for safety and performance. In situations where direct connection is possible, the complexities and potential issues associated with the vent connector can be bypassed entirely, simplifying the design and installation of the system.

In contrast, the other scenarios, such as being connected to an exterior vent or located in a basement, do not provide grounds for exemption from the vent connector requirement. Each of these cases still necessitates the use of a connector to maintain safety and efficiency standards.