HVAC Journeyman Practice Exam

Which air flow component is typically placed after the heat exchanger?

1. The cooling coil

2. A diverter unit

3. A bypass duct

4. A ventilator

The correct answer is: The cooling coil

The cooling coil is typically placed after the heat exchanger in an HVAC system to ensure that the air passes through the heat exchanger first, where it can be either heated or cooled depending on the system's operation. Once the air has gone through this initial temperature modification, it then flows into the cooling coil. The purpose of the cooling coil is to further lower the air temperature, removing additional heat and humidity before the conditioned air is distributed to the living spaces. In a well-designed system, this sequence enhances energy efficiency and indoor comfort. The heat exchanger handles the initial thermal exchange, while the cooling coil fine-tunes the air's temperature and humidity, making it suitable for occupant comfort. Additionally, placing the cooling coil after the heat exchanger allows for better control of temperature variations, ensuring that the air reaching the spaces is effectively conditioned. Other components like a diverter unit, bypass duct, or ventilator serve different functions in the HVAC system. These components may relate to air distribution, mixing fresh air, or redirecting airflow, but they do not typically follow the heat exchanger in the same functional capacity as the cooling coil.