The specific heat (Cp) of a substance refers to the amount of heat required to raise the temperature of a unit mass of that substance by one degree Celsius (or Kelvin) at a constant pressure. For R134a refrigerant, the specific heat varies depending on the temperature and pressure conditions.
At constant pressure (P) and typically around room temperature, the specific heat of R134a is approximately 1.51 kJ/(kg·K) or 0.361 Btu/(lb·°F).
It's important to note that specific heat can change with temperature and pressure. For accurate and precise calculations in refrigeration systems, it's best to use specific heat values corresponding to the actual operating conditions of the refrigerant. Manufacturers and reference tables can provide more comprehensive data for different temperature and pressure ranges.