Concepts for Comfortable Air-Conditioning – Simulation Using a Zonal Cabin Model and a Metrological Evaluation Based on Equivalent Temperature

Abstract

In the design of future electric vehicles, the air conditioning of the passenger compartment is considered as the largest auxiliary consumer. To test new climate control concepts and quantify their effectiveness in terms of user acceptance, energy efficiency and driving range, corresponding methods and tools are needed. This includes the numerical, experimental and subject-supported study regarding human thermal comfort.

New developed zonal models simulate air flow and temperature, surface temperature, pressure and also humidity in a closed environment. Predicting indoor environmental conditions in vehicle cabin is achieved in transient inhomogeneous load cases. With the combination of a radiation model, the long-wave radiation exchange between human and cabin is included in the heat balance equation with a high level of detail.

In order to improve the assessment of the local thermal conditions near the passenger, a climate measurement system (DressMAN 2.0) was developed by the Fraunhofer Institute for Building Physics (IBP). Using dedicated controllers and sensor devices the DressMAN is able to measure equivalent temperature on local segments for evaluation according to DIN EN ISO 14505-2. Based on these methods novel and existing concepts for heating have been tested with subjects in a cabin mock-up. The experiments used simulation-based methods and local climate measurement devices to compare and evaluate different climate control concepts.