81 Copyright by Goodheart-Willcox Co., Inc. Aft er studying this chapter, you will be able to: • Identify and defi ne heat and cold. • Identify and explain heat transfer methods. • Identify and explain change of state. • Identify latent heat and explain how it is absorbed and released from a substance. • Explain the basic refrigeration cycle. • Identify common refrigeration system components and the purpose of each. • Explain how heat load aff ects refrigeration system operation. absolute zero ambient air axial compressor block valve boiling change of state compressor condensing conduction convection cycling clutch orifi ce tube (CCOT) system evaporator pressure control evaporator pressure regulator (EPR) expansion valve fi lter fi xed orifi ce tube (FOT) freezing heat load heat pump heat transfer high pressure relief valve humidity latent heat melting pilot operated absolute (POA) valve pressure-temperature relationship radial compressor radiation reed valve relative humidity reversing valve sensible heat service fi tting state subcooling suction throttling valve (STV) sunload superheat superheated steam thermostatic expansion valve (TXV) valves-in-receiver (VIR) vaporizing variable displacement orifi ce tube (VDOT) wind chill Technical Terms Chapter 5 Principles of Refrigeration