What is the primary consequence of airflow restrictions in a vehicle HVAC system?

• A. Reduced airflow causing poorer heating and cooling performance
• B. Increased refrigerant efficiency
• C. Ventilation leakages stop all airflow
• D. Quick cabin cooling without fan use

Answer: (A)

Airflow across the heater core and evaporator controls how much heat or cooling actually reaches the cabin. When airflow is restricted, less air passes over these components, so heat transfer is limited. The result is slower heating or cooling and often uneven temperatures throughout the cabin, meaning overall poorer HVAC performance. The other options don’t fit because restricting airflow doesn’t increase refrigerant efficiency, it doesn’t suddenly stop all air from flowing, and cooling without using the fan isn’t plausible since air movement is needed to transfer the cool from the evaporator into the cabin.