Micro-Cooling/Heating Strategy for Energy Efficient HVAC System

Energy efficient HVAC system is becoming increasingly important as higher Corporate Average Fuel Economy (CAFE) standards are required for future vehicle products. The present study is a preliminary attempt at designing energy efficient HVAC system by introducing localized heating/cooling concepts without compromising occupant thermal comfort. In order to achieve this goal of reduced energy consumption while maintaining thermal comfort it is imperative that we use an analytical model capable of predicting thermal comfort with reasonable accuracy in a non-homogenous enclosed thermal environment such as a vehicle's passenger cabin. This study will primarily focus on two aspects: (a) energy efficiency improvements in an HVAC system through micro-cooling/heating strategies and (b) validation of an analytical approach developed in GM that would support the above effort. The paper will discuss the analytical approach adopted in this study, its application in predicting overall comfort and sensation levels for various micro-cooling strategies, and subsequently comparing these predicted results with the real human subject test. The combination of the present CFD work coupled with the thermal comfort simulations will allow for the exploration of different microclimate control strategies as they relate to occupant thermal comfort for an “Energy Efficient HVAC System”.