what is delta t temperature
âDelta Tâ is the most common use of the word delta in the HVAC industry, meaning temperature difference. If the temperature before a cooling coil is 75F and the temperature after the cooling coil is 55F, subtract 55F from a 75F to find a delta t of 20F. Since the first time a service technician tried to explain delta to me, Iâve wrestled with a way to make the definition a little easier to swallow.