what is delta temperature
Therefore, the total delta T between the ambient air and saturated refrigerant is about 10 deg C (20 deg F). Let's start with some clarifications: A delta-T is the change in temperature of a single substance or flow of substance. The evaporator delta-T is the temperature difference between the air entering the coil and the air leaving the coil. A TD is the temperature difference between two different substances or flows of substances. The evaporator TD is the temperature difference between the air entering the coil and the saturated refrigerant.