When a Baffle is used to prevent rain from entering an air supply opening, how much can it reduce the required free area opening?

When a baffle is utilized to prevent rain from entering an air supply opening, it is designed to redirect water while maintaining the airflow necessary for combustion processes. In this context, the correct understanding is that the addition of a baffle does not inherently reduce the required free area opening necessary for air supply.

This means that the air supply opening should retain its full capacity to ensure that adequate airflow is maintained, even with the installation of the baffle. The purpose of the baffle is primarily to block water ingress rather than to lessen the airflow potential; hence, it does not reduce the opening size requirement by any percentage.

This principle emphasizes the importance of maintaining sufficient air supply for appliances while adding protective features to prevent rain intrusion.