What term describes obstructions that hinder airflow in an HVAC system?

• A. Airflow Restrictions
• B. Dynamic Humidity
• C. Thermal Expansion
• D. Venturi Effect

Answer: (A)

Airflow restrictions describe obstructions that hinder airflow in an HVAC system. Anything that increases resistance to air movement—such as a clogged filter, dirty coil, blocked or kinked duct, or a closed or undersized damper—reduces the air delivered to spaces and makes the blower work harder, which can cause uneven temperatures and higher energy use. This term best captures the idea of obstacles that physically impede air flow. Dynamic humidity relates to moisture content, thermal expansion deals with how materials grow with temperature, and the Venturi effect describes how velocity and pressure change in a constricted passage, not the general label for obstructions.