The compressor’s discharge temperature can tell the service technician what is going on inside a air conditioning system. The discharge is a reflection of the hottest part of a air conditioning system, and there are limits as to how hot a discharge temperature should be. This article will explore discharge temperatures and their limits. The discharge temperature can be measured by placing an insulated thermistor or thermocouple on the discharge line about 3 to 4 in. From the compressor.