Impact of measurable physical phenomena on contact thermal comfort

Abstract

Abstract. Cabin HVAC (Heating Ventilation and Air-conditioning) systems have become an essential part of personal vehicles as demands for comfortable transport are still rising. In fact, 85 % of the car trips in Europe are shorter than 18 km and last only up to 30 minutes. Under such conditions, the HVAC unit cannot often ensure desired cabin environment and passengers are prone to experience thermal stress. For this reason, additional comfort systems, such as heated or ventilated seats, are available on the market. However, there is no straightforward method to evaluate thermal comfort at the contact surfaces nowadays. The aim of this work is to summarise information about heated and ventilated seats. These technologies use electrical heating and fan driven air to contact area in order to achieve enhanced comfort. It is also expected, that such measures may contribute to lower energy consumption. Yet, in real conditions it is almost impossible to measure the airflow through the ventilated seat directly. Therefore, there is a need for an approach that would correlate measurable physical phenomena with thermal comfort. For this reason, a method that exploits a measurement of temperatures and humidity at the contact area is proposed. Preliminary results that correlate comfort with measurable physical phenomena are demonstrated.

Human Thermal Comfort and Heat Removal Efficiency for Ventilation Variants in Passenger Cars

“…The total simulation time was 30 min as the majority of car trips are shorter than 18 km, which lasts only up to 30 min [22]. In case of transient simulation times, the step size is critical, and the time step size at the beginning of the transient simulation affects the end results and is crucial for obtaining satisfactory as well as precise simulation results.…”

Research and Analysis of the Propagation of Vertical Vibrations in the Arrangement of a Vehicle Seat—A Child’s Seat

“…Vehicle seats with sensors informing whether the child has properly fastened seat belts now exists, as well as an ISOFIX base with a sensor that provides information about the correct fastening of the seat [50][51][52][53][54]. It should be noted, however, that there are solutions for child seats, which are additionally equipped with a temperature sensor and sensors that allow for blood pressure measurements [55][56][57][58][59][60], Equipping safety seats with various types of sensors increases ergonomic comfort and improves safety.…”