What contributes significantly to the work required by the blower?

The work required by the blower is significantly impacted by the types of ducts and air filters used in the system. This is because the design and condition of ducts can create varying levels of resistance to airflow. Ducts that are too small, poorly insulated, or have many bends can restrict air movement, requiring the blower to work harder to maintain adequate airflow throughout the system. Similarly, air filters with high resistance to airflow—especially if they are dirty or not appropriately rated for the system—can also increase the workload on the blower.

Air filters are integral to the system, as they trap dust and contaminants to maintain indoor air quality. However, if they are too restrictive, they can create pressure drops that the blower must overcome. Therefore, understanding the specifications and maintenance of ducts and filters is essential in evaluating and optimizing blower performance.

The other factors mentioned, like the age of the equipment, the blower's motor type, and outdoor temperature, can influence system performance, but they do not have as direct an impact on the work being done by the blower as the duct and filter types do. Proper selection and maintenance of these components can lead to enhanced efficiency and reduced energy consumption.