Temperature Difference - Delta T

Delta T is the difference of temperatures between two measuring points, differing either in time and/or position. The symbol is the Greek capital letter delta, used mathematically to describe the difference of any changeable quantity. In processes, Delta T shows the difference between two measured temperatures.

The equation is: Delta T = T2 - T1

Applications include measuring heat exchanger efficiency, checking heating or cooling system performance, and monitoring building climate control by comparing supply and return water temperatures. When monitoring a heat exchanger over time, delta T changes indicate the degree of fouling present. Combined with flow rate data, delta T enables calculation of the Heat Transfer Coefficient.

Unit conversions (without adding or subtracting 32): Delta T degF = Delta T degC x 9/5 and Delta T degC = Delta T degF x 5/9