Where should screens not be installed in relation to duct or weather cap terminations?

Screens should not be installed at the termination point of ducts or weather caps because their presence can create unnecessary resistance to airflow and potentially obstruct the proper ventilation. When screens are placed at the termination, they can trap debris and create a blockage, which can lead to reduced efficiency and increased pressure within the duct system. This can ultimately result in poor ventilation performance and an increased risk of moisture buildup, which could contribute to mold growth and other issues.

In contrast, it is generally more acceptable to have screens at the inlet or other locations where they can filter out larger debris without interfering with the airflow dynamics at critical termination points. By avoiding screens at the termination, systems are able to maintain optimal airflow and function more effectively.