| TR | Tons of refrigeration | |
| hg | Enthalpy of Refrigerant in gaseous phase | |
| R134a | 1,1,1,2-tetraflouroethane | |
| R1270 | Propylene | |
| R125 | 1,1,12,2-pentaflouroethane | |
| R152a | 1,1-diflouroethane | |
| Td | Discharge Temperature | |
| R | Compression ratio | |
| g | Ratio of heat capacities | |
| Ts | Suction temperature | |
| P | Pressure | |
| H | Enthalpy | |
| U | Internal energy | |
| V | Volume | |
| Rev | Reversible | |
| h | Efficiency | |
| Wc | Compressor work | |
| Ws | Real work | |
|
| Mass flow rate | |
| D | Change | |
| Cp | Specific heat capacity t constant pressure | |
| Cv | Specific heat capacity t constant volume | |
| R | Universal gas constant | |
| Isen | Isentropic | |
| MR | Mass flow of refrigerant | |
| Qevap | Evaporator duty | |
| Qcond | Condenser duty | |
| S | Enthropy | |
| TXV | Thermal Expansion valve | |
| U | Coefficient heat transfer | |
| A | Area | |
| COP | Coefficient of performance | |
| T/h | Tones per hour | |
| X | Quality of refrigerant | |
| Cv | Valve flow Coefficient | |
| Nt | Number of tubes | |
| 1, 2, 3, 4 | States on P-h diagram | |
| ρ | Density | |
| C6H12 | Cyclohexane | |