What does the term "Delta T" refer to?

The term "Delta T" specifically refers to the difference in temperature between two points, which in this context is the difference between inside and outside temperatures. This concept is crucial in various applications, such as HVAC systems, where understanding the temperature variance helps in assessing heating and cooling needs. By knowing the "Delta T," technicians can optimize energy efficiency and maintain comfortable environments.

In HVAC systems, the delta temperature aids in determining appropriate airflow rates, heat exchange efficiency, and system performance. It's an essential factor in ensuring systems are operating under ideal conditions, which improves overall efficiency and comfort.

The other choices do not accurately describe what "Delta T" signifies in this context. For example, the temperature at which a liquid turns to gas is commonly referred to as the boiling point, while the average temperature of the air does not convey the concept of a temperature difference. The temperature of boiling water is a specific measurement and does not relate to the comparative temperature difference between two environments.