NATE Air Conditioning and Heat Pumps Practice Exam

What issue can arise if a proper trap is not used on the condensate drain of a draw-through unit?

1. Condensate water will not drain properly and will back up above the primary drain

2. Conditioned supply air will escape through the condensate drainpipe

3. Ice will accumulate on the evaporator coil

4. Stress on the connection fitting at the evaporator will cause the pipe to crack

The correct answer is: Condensate water will not drain properly and will back up above the primary drain

The correct response outlines a critical function of a condensate trap in a draw-through unit. A proper trap is designed to maintain a water seal that prevents air from entering the condensate drain system. If the trap is not used or is improperly installed, there is a significant risk that condensate water will not drain effectively. This can lead to water pooling in the drain pan, increasing the likelihood of backups that can exceed the primary drain's capacity. When water accumulates beyond the designed limits, it can lead to leaks or even damage to surrounding components, creating further operational problems. In contrast, while the other responses touch on possible issues related to airflow and the system's performance, they do not directly relate to the primary consequence of not having a proper trap. Conditioned air escaping through the drainpipe or ice accumulation on the evaporator coil may indicate other issues, but they do not specifically arise from the absence of a trap. Similarly, stress on connection fittings is more indicative of physical strain rather than a direct result of improper drainage. Thus, the issue of drainage backing up is the most immediate and severe consequence of not using a proper condensate trap.