Air-conditioning in the cabins of passenger cars

ArticleThe objective of this paper is to analyse the current state of the constructional design and operational conditions of air - conditioning device in passenger cars. The research was focused on the function of air - conditioning equipment of passenger cars Skoda and KIA in various modes of operation during the winter, spring and summer season at different levels of air conditioning (without air - conditioning, minimum, medium and maximum level). Air temperature, air humidity, globe temperature, CO 2 concentration, dust concentration and noise inside the cabin w ere measured. Solar radiation plays a big role to rise up temperature inside the cabin. It resulted in the higher values of globe temperature than temperature of the air. The results of the measurements showed that CO 2 values were significantly lower than 2,500 ppm at minimum air - conditioning, lower than 600 ppm at medium and lower than 500 ppm at maximum level of air - conditioning. For all vehicles, dust concentration was greater when it measured with the air conditioning switched off than with the air con ditioning system turned on. The measurements confirmed that the total dust concentration was not more than 47 μg m - 3 , PM 10 lower than 28 μg m - 3 and PM 1 lower than 27 μg m - 3 . The noise levels ranged from 49.1 to 68.7 dB(A). The air - conditioning had very positive impact on the inside comfort in car cabins from all points of view during all periods of the year

Extraordinary Passive Safety in Cars Using a Sensor Network Model

Context: The automobile industry has included active and passive safety. Active safety incorporates elements to avoid crashes and collisions. Some elements are ABS brakes and stabilization bars, among others. On the other hand, passive safety avoids or minimizes damage to the occupants in the event of an accident. Some passive safety features include seat belts and front and curtain airbags for the driver and other occupants. Method: In this research work, we propose a new category called Extraordinary Passive Safety (XPS). A model of a sensor network was designed to inspect the conditions inside the car to detect fire, smoke, gases, and extreme temperatures. The sensors send data to a device (DXPS) capable of receiving and storing the data. Results: Each sensor collects data and sends it to the DXPS every period. The sensor sends 0s while there is no risk, and 1s when it detects a risk. When the DXPS receives a 1, the pattern is evaluated, and the risk is identified. Since there are several sensors, the reading pattern is a set of 0s (000000). When a pattern with one or more 1s (000100, 010101) is received, the DXPS can send an alert or activate a device. Conclusions: The proposed solution could save the lives of children left in the car or people trapped when the car catches fire. As future work, it is intended to define the devices to avoid or minimize damage to the occupants such as oxygen supply, gas extraction, regulating the temperature, among other

Study of the optimization of a miniaturized gas sensor for odor monitoring

Climate change and the crisis of non-renewable natural resources have fostered a change in people's mentality, pushing them towards a future of shared mobility. This study aims to offer a solution to one of the main drawbacks of this type of mobility, the discomfort generated by malodors and poor air quality in shared-use vehicles. To that end, the use of an odor monitoring module is proposed which, through gas sensors, allows to improve the air quality inside vehicles after its use. In this thesis we find a study of the technology for odor tracking, the design and manufacture of a prototype for the module and its subsequent implementation in vehicles. The study concludes with pilot tests on different vehicles which contribute to the parameterization of the system, laying the foundations for projects with real application

Energy Efficient Air Quality Solutions for Vehicle Cabins

Maintaining a good air quality level is essential for reducing potential health risks for human beings. Vehicle cabin is one common environment where people spend increasing amount of time in modern societies. It’s an environment challenged by elevated pollutants from surrounding traffics, especially small particles like PM2.5 and UFP (Ultrafine particles). To efficiently reduce or remove the pollutants from incoming air is one essential focus for development of future vehicles. To achieve that goal with energy efficient solutions would be even more important in the trend of emerging electric vehicles. The objective of this thesis is to evaluate and propose solutions for improved cabin air quality and energy efficiency, which could be used in the development of vehicle climate system. The work has been conducted through vehicle measurements on road in two different locations, development of an air quality model, modelling of increased recirculation in the climate ventilation strategy, as well as measurements on new prototypes in both rig and road conditions. The purpose of the road measurements is to set the baseline of current air quality levels and evaluate the important influencing factors such as filter age and ventilation settings. The purpose of the model development is to enable a repeatable and comprehensive evaluation environment, which is later used to evaluate the strategy of increased air recirculation under common driving conditions. The purpose of the measurements on prototypes is to evaluate one solution of using EPA (Efficient Particulate Air) or HEPA (high-efficiency particulate air) filters as pre-filters, to prove the concept and the limitations. The results are showing that cabin particles are highly influenced by the outside particle concentrations, the filter design and status, and to some extent the ventilation settings. Besides the application of pre-ionization assisted filtration was proved valuable. The air quality model, implemented in an existing climate system model, is validated with road measurements. Modelling of increased recirculation results in significant reduction of energy use and particles. In warm climate it’s more applicable to avoid fog risks and in all climates the use of high recirculation (for example 70%) should be evaluated based on the number of passengers. One way to achieve that is adding a control based on cabin CO2 concentration in the climate system.\ua0 It is also shown feasible to improve air quality using an EPA/HEPA pre-filter. The main limitations come from space and acceptable pressure-drop in the relatively compact environment

Opportunistic sensing for road pavement monitoring

Road surface state monitoring is of main concern for road infrastructure owners. Hence dedicated measurement campaigns using laser scanning and image analysis are performed on a regular basis. Yet, this type of monitoring comes at a high labor cost and thus it is often limited in coverage and update frequency. This paper proposes opportunistic sensing as an alternative approach. Using sound and vibration sensing in cars that are on the road for other purposes and exploiting the advent of cheap communication, big data, and machine learning, timely information on road state is obtained. Results are compared to laser scanning for spatial frequencies between 0.1 and 100 cycles/m showing the applicability of the method. Results are also used for classification and labeling of road surfaces regarding their effect on rolling noise. Mapping illustrates the coverage of highways and local roads obtained in a few months with as few as seven cars

Investigation of low-cost infrared sensing for intelligent deployment of occupant restraints

In automotive transport, airbags and seatbelts are effective at restraining the driver and passenger in the event of a crash, with statistics showing a dramatic reduction in the number of casualties from road crashes. However, statistics also show that a small number of these people have been injured or even killed from striking the airbag, and that the elderly and small children are especially at risk of airbag-related injury. This is the result of the fact that in-car restraint systems were designed for the average male at an average speed of 50 km/hr, and people outside these norms are at risk. Therefore one of the future safety goals of the car manufacturers is to deploy sensors that would gain more information about the driver or passenger of their cars in order to tailor the safety systems specifically for that person, and this is the goal of this project. This thesis describes a novel approach to occupant detection, position measurement and monitoring using a low-cost thermal imaging based system, which is a departure from traditional video camera-based systems, and at an affordable price. Experiments were carried out using a specially designed test rig and a car driving simulator with members of the public. Results have shown that the thermal imager can detect a human in a car cabin mock up and provide crucial real-time position data, which could be used to support intelligent restraint deployment. Other valuable information has been detected such as whether the driver is smoking, drinking a hot or cold drink, using a mobile phone, which can help to infer the level of driver attentiveness or engagement

Atmos Environ (1994)

Advanced automobile technology, developed infrastructure, and changing economic markets have resulted in increasing commute times. Traffic is a major source of harmful pollutants and consequently daily peak exposures tend to occur near roadways or while traveling on them. The objective of this study was to measure simultaneous real-time particulate matter (particle numbers, lung-deposited surface area, PM2.5, particle number size distributions) and CO concentrations outside and in-cabin of an on-road car during regular commutes to and from work. Data was collected for different ventilation parameters (windows open or closed, fan on, AC on), whilst traveling along different road-types with varying traffic densities. Multiple predictor variables were examined using linear mixed-effects models. Ambient pollutants (NOx, PM2.5, CO) and meteorological variables (wind speed, temperature, relative humidity, dew point) explained 5-44% of outdoor pollutant variability, while the time spent travelling behind a bus was statistically significant for PM2.5, lung-deposited SA, and CO (adj-R2 values = 0.12, 0.10, 0.13). The geometric mean diameter (GMD) for outdoor aerosol was 34 nm. Larger cabin GMDs were observed when windows were closed compared to open (b = 4.3, p-value = <0.01). When windows were open, cabin total aerosol concentrations tracked those outdoors. With windows closed, the pollutants took longer to enter the vehicle cabin, but also longer to exit it. Concentrations of pollutants in cabin were influenced by outdoor concentrations, ambient temperature, and the window/ventilation parameters. As expected, particle number concentrations were impacted the most by changes to window position / ventilation, and PM2.5 the least. Car drivers can expect their highest exposures when driving with windows open or the fan on, and their lowest exposures during windows closed or the AC on. Final linear mixed-effects models could explain between 88-97% of cabin pollutant concentration variability. An individual may control their commuting exposure by applying dynamic behavior modification to adapt to changing pollutant scenarios.CC999999/Intramural CDC HHS/United States2017-12-26T00:00:00Z29284988PMC5743207vault:2575

Exposure to Air Pollution in Transport Microenvironments

People spend approximately 90% of their day in confined spaces (at home, work, school or in transit). During these periods, exposure to high concentrations of atmospheric pollutants can pose serious health risks, particularly to the respiratory system. The objective of this paper is to define a framework of the existing literature on the assessment of air quality in various transport microenvironments. A total of 297 papers, published from 2002 to 2021, were analyzed with respect to the type of transport microenvironments, the pollutants monitored, the concentrations measured and the sampling methods adopted. The analysis emphasizes the increasing interest in this topic, particularly regarding the evaluation of exposure in moving cars and buses. It specifically focuses on the exposure of occupants to atmospheric particulate matter (PM) and total volatile organic compounds (TVOCs). Concentrations of these pollutants can reach several hundreds of µg/m3 in some cases, significantly exceeding the recommended levels. The findings presented in this paper serve as a valuable resource for urban planners and decision-makers in formulating effective urban policies