🔍 Key Concepts

• Refrigeration effect per unit mass of each refrigerant (how much heat 1 kg can remove) • Specific volume of the suction vapor (how big the vapor is at compressor inlet) and how that affects compressor size • The idea of volumetric refrigeration capacity (cooling per unit of compressor displacement)

💭 Think About

• Think about what really determines how big a compressor must be: is it the weight of refrigerant moved, or the volume of vapor the compressor has to handle? • For the same cooling capacity, which refrigerant would need the least suction volume flow into the compressor? • How do higher operating pressures at the evaporator affect the density of the suction vapor and, in turn, the compressor displacement needed?

✅ Before You Answer

• Compare which refrigerant has the highest vapor density at typical evaporator conditions—higher density usually means a smaller compressor for the same capacity. • Consider which refrigerant is known for very high operating pressures and correspondingly small displacement compressors. • Make sure you distinguish between latent heat per kg and volumetric refrigeration capacity—the latter is what really ties to compressor physical size.