scholarly journals Head sweat rate prediction for thermal comfort assessment of bicycle helmets

2015 ◽  
Vol 4 (S1) ◽  
Author(s):  
Peter Bröde ◽  
Guido De Bruyne ◽  
Jean-Marie Aerts ◽  
Tiago S Mayor ◽  
Dusan Fiala
2018 ◽  
Vol 36 (3) ◽  
pp. 165-179 ◽  
Author(s):  
Meredith McQuerry ◽  
Roger Barker ◽  
Emiel DenHartog

Structural firefighter prototype designs incorporating ventilation, stretch, and modularity were developed following Watkins’ functional design process. Prototypes were designed and manufactured, including single-layer, vented, stretch, and combination prototypes. Prototype garments were evaluated for improved thermal comfort and heat loss using sweating thermal manikin assessments in two conditions: static (standing still with no wind) and dynamic (walking with wind). Raw thermal and evaporative resistance data from the manikin testing were input into a thermal modeling software system (RadTherm®) and physiological responses (core temperature, skin temperature, and sweat rate) were predicted for each prototype. A significant improvement in heat loss was measured when ventilation openings and modularity were added to the design of the clothing system. The single-layer, vented, and combination prototypes also had significantly lower increases in predicted physiological responses.


2010 ◽  
Vol 2 (2) ◽  
pp. 2413-2418 ◽  
Author(s):  
Firoz Alam ◽  
Harun Chowdhury ◽  
Zakaria Elmir ◽  
Andika Sayogo ◽  
James Love ◽  
...  

2000 ◽  
Vol 122 (4) ◽  
pp. 457-460 ◽  
Author(s):  
Jennifer Reid ◽  
Eric L. Wang

This article describes the design and development of a system that is capable of quantifying the thermal comfort of bicycle helmets. The motivation for the development of the system stems from the desire both to increase helmet use and to provide the designer with a quantitative method of evaluating the thermal comfort of a helmet. The system consists of a heated mannequin head form, a heated reference sphere, a small wind tunnel, and a data acquisition system. Both the head form and the reference sphere were instrumented with thermocouples. The system is capable of simulating riding speeds ranging from 4.5–15.5 m/s. A cooling effectiveness, C1, that is independent of both ambient conditions and wind velocity is defined as a measure of how well the helmet ventilates as compared to the reference sphere. The system was validated by testing six commercially available bicycle helmets manufactured between approximately 1992 and 1998. [S0148-0731(00)02304-9]


2019 ◽  
Vol 9 (15) ◽  
pp. 3170 ◽  
Author(s):  
Ali Youssef ◽  
Jeroen Colon ◽  
Konstantios Mantzios ◽  
Paraskevi Gkiata ◽  
Tiago Mayor ◽  
...  

Bicyclists can be subjected to crashes, which can cause injuries over the whole body, especially the head. Head injuries can be prevented by wearing bicycle helmets; however, bicycle helmets are frequently not worn due to a variety of reasons. One of the most common complaints about wearing bicycle helmets relates to thermal discomfort. So far, insufficient attention has been given to the thermal performance of helmets. This paper aimed to introduce and develop an adaptive model for the online monitoring of head thermal comfort based on easily measured variables, which can be measured continuously using impeded sensors in the helmet. During the course of this work, 22 participants in total were subjected to different levels of environmental conditions (air temperature, air velocity, mechanical work and helmet thermal resistance) to develop a general model to predict head thermal comfort. A reduced-order general linear regression model with three input variables, namely, temperature difference between ambient temperature and average under-helmet temperature, cyclist’s heart rate and the interaction between ambient temperature and helmet thermal resistance, was the most suitable to predict the cyclist’s head thermal comfort and showed maximum mean absolute percentage error (MAPE) of 8.4%. Based on the selected model variables, a smart helmet prototype (SmartHelmet) was developed using impeded sensing technology, which was used to validate the developed general model. Finally, we introduced a framework of calculation for an adaptive personalised model to predict head thermal comfort based on streaming data from the SmartHelmet prototype.


1988 ◽  
Vol 58 (3) ◽  
pp. 166-173 ◽  
Author(s):  
Donna H. Branson ◽  
Lynda Abusamra ◽  
Carolyn Hoener ◽  
Sandra Rice

Military subjects participated in a study to evaluate four glove liners worn beneath chemical protective gloves, with regard to sweating of the hands, manual dexterity performance, and perceived comfort in a moderate thermal environment. Although there was a trend for subjects wearing the standard Army liner to experience the lowest sweat rate, the liner effect was not significant due to individual variation. No liner differences were found for manual dexterity performance, hand skin temperature, perceived temperature, and thermal comfort. Differences by liner were found for tactile descriptors used to assess liner comfort. Skin temperature, perceived temperature, and perceived thermal discomfort increased over the duration of the two-hour test, regardless of the liner worn.


2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Jai Kyoung Sim ◽  
Sunghyun Yoon ◽  
Young-Ho Cho

ICCREM 2020 ◽  
2020 ◽  
Author(s):  
Boshuai Dong ◽  
Chunjing Shang ◽  
Ming Tong ◽  
Jianhong Cai

2019 ◽  
pp. 53-65
Author(s):  
Renata Domingos ◽  
Emeli Guarda ◽  
Elaise Gabriel ◽  
João Sanches

In the last decades, many studies have shown ample evidence that the existence of trees and vegetation around buildings can contribute to reduce the demand for energy by cooling and heating. The use of green areas in the urban environment as an effective strategy in reducing the cooling load of buildings has attracted much attention, though there is a lack of quantitative actions to apply the general idea to a specific building or location. Due to the large-scale construction of high buildings, large amounts of solar radiation are reflected and stored in the canyons of the streets. This causes higher air temperature and surface temperature in city areas compared to the rural environment and, consequently, deteriorates the urban heat island effect. The constant high temperatures lead to more air conditioning demand time, which results in a significant increase in building energy consumption. In general, the shade of the trees reduces the building energy demand for air conditioning, reducing solar radiation on the walls and roofs. The increase of urban green spaces has been extensively accepted as effective in mitigating the effects of heat island and reducing energy use in buildings. However, by influencing temperatures, especially extreme, it is likely that trees also affect human health, an important economic variable of interest. Since human behavior has a major influence on maintaining environmental quality, today's urban problems such as air and water pollution, floods, excessive noise, cause serious damage to the physical and mental health of the population. By minimizing these problems, vegetation (especially trees) is generally known to provide a range of ecosystem services such as rainwater reduction, air pollution mitigation, noise reduction, etc. This study focuses on the functions of temperature regulation, improvement of external thermal comfort and cooling energy reduction, so it aims to evaluate the influence of trees on the energy consumption of a house in the mid-western Brazil, located at latitude 15 ° S, in the center of South America. The methodology adopted was computer simulation, analyzing two scenarios that deal with issues such as the influence of vegetation and tree shade on the energy consumption of a building. In this way, the methodological procedures were divided into three stages: climatic contextualization of the study region; definition of a basic dwelling, of the thermophysical properties; computational simulation for quantification of energy consumption for the four facade orientations. The results show that the façades orientated to north, east and south, without the insertion of arboreal shading, obtained higher values of annual energy consumption. With the adoption of shading, the facades obtained a consumption reduction of around 7,4%. It is concluded that shading vegetation can bring significant climatic contribution to the interior of built environments and, consequently, reduction in energy consumption, promoting improvements in the thermal comfort conditions of users.


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