Which factor can negatively affect the performance of an HVAC system?

Blocked air ducts can significantly hinder the performance of an HVAC system because they restrict airflow. When ducts are blocked by dust, debris, or physical obstructions, the system struggles to circulate air effectively throughout the space. This can lead to uneven heating or cooling, increased energy consumption, and excessive strain on the HVAC components, ultimately resulting in potential damage or the need for repairs.

In contrast, regular maintenance helps keep the system operating efficiently by ensuring all components are clean and functioning properly. Proper insulation aids in maintaining desired temperature levels and prevents energy loss. Correct refrigerant levels are crucial for optimal cooling efficiency and system performance. Each of these factors supports effective operation, whereas blocked air ducts directly impede airflow and compromise system efficiency.