Effect of relative humidity and temperature control on in-cabin thermal comfort state: Thermodynamic and psychometric analyses

• Published in: Applied thermal engineering Vol. 31; no. 14; pp. 2636 - 2644
• Main Authors: Alahmer, A., Omar, M.A., Mayyas, A., Dongri, Shan
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.10.2011; Elsevier
• Subjects: Air conditioning. Ventilation; Applied sciences; Bulbs; Comfort; Drying; Energy; Energy. Thermal use of fuels; Evaporative cooler; Exact sciences and technology; Heat transfer; Heating, air conditioning and ventilation; Human; Human comfort; PMV; PPD; Psychometrics; Relative humidity; Techniques, equipment. Control. Metering; Theoretical studies. Data and constants. Metering; Thermal comfort; Thermodynamics; Vehicular air conditioning; Relative humidity; PMV; Vehicular air conditioning; Evaporative cooler; PPD; Human comfort; Air conditioning; Thermodynamics; Cooler; Humidity; Temperature control; Implementation
• ISSN: 1359-4311
• DOI: 10.1016/j.applthermaleng.2011.04.033

This manuscript discusses the effect of manipulating the Relative Humidity RH of in-cabin environment on the thermal comfort and human occupants’ thermal sensation. The study uses thermodynamic and psychometric analyses, to incorporate the effect of changing RH along with the dry bulb temperature on human comfort. Specifically, the study computes the effect of changing the relative humidity on the amount of heat rejected from the passenger compartment and the effect of relative humidity on occupants comfort zone. A practical system implementation is also discussed in terms of an evaporative cooler design. The results show that changing the RH along with dry bulb temperature inside vehicular cabins can improve the air conditioning efficiency by reducing the heat removed while improving the Human comfort sensations as measured by the Predicted Mean Value PMV and the Predicted Percentage Dissatisfied PPD indices. ► Investigates the effect of controlling the RH and dry bulb temperature on in-cabin thermal comfort and sensation. ► Conducts the thermodynamic and psychometric analyses for changing the RH and temperature for in-cabin air conditioning. ► Discusses a possible system implementation through an evaporative cooler design.