Uncertainty, Equation of state, Air conditioner, Refrigerant
In previous literature, the uncertainty analyses of experimental results of air conditioners usually ignored the uncertainty due to the equation of state (EoS) of the refrigerants. One possible reason was that the uncertainty reported in the EoS literature was much smaller than the one of the measurement. However, with the advancement of measurement technologies, the impact of measurement uncertainty on the air conditioner performance calculation is lowered and becomes on par with that of the EoS. Simultaneously, new research findings give more comprehensive understanding of the EoS uncertainties, such as that the uncertainty of EoS reported in previous studies was underestimated under some conditions. To examine if the uncertainty of experimental results of a thermal system are significantly affected by the new findings, an uncertainty analysis is carried out with experimental data of an air conditioner using propane. The results show that the uncertainty of the EoS has a more significant impact on experimental results involving saturation temperature such as subcooling and superheat measurement than the uncertainties of the measurement, while its impact on the uncertainty of the measured heat transfer rate is still not as significant in most cases.