What measurements are necessary to evaluate a complaint of "drafty" operation with a heating system?

To assess a complaint of "drafty" operation with a heating system, evaluating the system's temperature difference (system TD), airflow drop, and static pressure is essential. The temperature difference allows you to understand the heating output relative to the desired indoor temperature. If the temperature difference is not adequate, the system may not be effectively delivering the necessary heat, contributing to drafts.

Examining the airflow drop helps identify any restrictions or inefficiencies in the ductwork or the heating system itself. A significant drop could indicate that the system is not moving enough air, potentially leading to cold spots and the sensation of drafts.

Static pressure measurement is crucial for determining how well the system is overcoming duct resistance to deliver adequate airflow. High static pressure could indicate blockages or design flaws in the duct system, which can also result in uneven heating and drafts.

Together, these measurements provide a comprehensive understanding of the system's operational efficiency and help pinpoint the source of the drafty conditions.