At which point in an evaporator coil are the pressure-temperature chart values indicated?

At which point in an evaporator coil are the pressure-temperature chart values indicated?

• A. At the entry point of the coil
• B. At the mid-point of the coil
• C. At the exit point of the coil
• D. At the first third of the coil

Answer: (B)

The correct point on an evaporator coil where pressure-temperature chart values are indicated is generally at the exit point of the coil. At this location, the refrigerant has absorbed heat from the surrounding air or fluid and has undergone a phase change from liquid to vapor. This is where the refrigerant pressure and temperature can be accurately measured to reflect its current state after it has picked up the heat. The mid-point of the coil would not provide an accurate representation because the refrigerant is still transitioning, and its properties would not be fully represented as it would be variable throughout the coil. Similarly, measuring at the entry point would not reflect the heat absorption and phase change process, leading to inaccurate data regarding the refrigerant's state. The first third of the coil does not account for the complete thermal exchange that occurs, rendering that measure inadequate as well. Therefore, focusing on the exit point provides the clearest understanding of the refrigerant's behavior after absorbing heat.

The correct point on an evaporator coil where pressure-temperature chart values are indicated is generally at the exit point of the coil. At this location, the refrigerant has absorbed heat from the surrounding air or fluid and has undergone a phase change from liquid to vapor. This is where the refrigerant pressure and temperature can be accurately measured to reflect its current state after it has picked up the heat.

The mid-point of the coil would not provide an accurate representation because the refrigerant is still transitioning, and its properties would not be fully represented as it would be variable throughout the coil. Similarly, measuring at the entry point would not reflect the heat absorption and phase change process, leading to inaccurate data regarding the refrigerant's state. The first third of the coil does not account for the complete thermal exchange that occurs, rendering that measure inadequate as well. Therefore, focusing on the exit point provides the clearest understanding of the refrigerant's behavior after absorbing heat.