RVTI Level 1 Certification Practice Test

The delta temperature is a key indicator of an air conditioner functioning properly because it measures the difference between the return air temperature and the supply air temperature. When an air conditioner operates efficiently, the temperature drop (or delta) across the coil reveals how effectively it is removing heat from the indoor air. A typical delta temperature range is between 15 to 20 degrees Fahrenheit for many residential systems; if the delta temperature falls within this range, it suggests that the system is effectively cooling the space.

While noise level, external airflow, and visual inspection can provide clues about the operation of an air conditioner, they do not directly measure the unit's efficiency in cooling. Noise might indicate an issue but is not definitively an indicator of proper functioning. Similarly, while airflow is important for the circulation of air, it does not provide a comprehensive assessment of the cooling performance like the delta temperature does. Visual inspection can help identify obvious physical issues, but it won’t give any quantitative measure of performance. Thus, delta temperature is the most reliable measure for evaluating whether the air conditioner is working as it should.