HVAC Journeyman Practice Exam

What is the consequence of not using the correct size duct in a HVAC system?

1. Higher installation costs

2. Improper system performance

3. Increased energy bills

4. All of the above

The correct answer is: All of the above

Using the correct size duct in an HVAC system is crucial for several reasons, all of which lead to the comprehensive outcomes associated with the answer provided. When ducts are incorrectly sized, the air distribution throughout the space can be adversely affected, resulting in improper system performance. If ducts are too small, they may restrict airflow, causing the system to work harder to push air through, which can lead to uneven heating or cooling. Conversely, ducts that are too large can lead to low air velocity and insufficient air delivery at the furthest reaches of the system. This imbalance not only affects comfort levels but can also impact the overall efficiency of the HVAC system, increasing the likelihood of mechanical failures and necessitating more frequent repairs. Additionally, improper duct sizing often results in higher energy bills. When the system is constantly running at inefficient levels due to airflow issues, it consumes more energy. This increased demand translates into higher utility costs, straining both the homeowner's budget and the energy grid as a whole. Furthermore, although initial installation costs may not drastically change with duct sizing, potential repairs and modifications stemming from performance issues can accumulate, leading to increased overall expenses. Therefore, the consequences of not using the correct size duct encompass all aspects: installation costs, system performance, and