Abstract: This article mainly of office chair seat surface thermal comfort to explore, office chair thermal comfort of significance and research status is introduced proposed effects of office chair seat surface thermal comfort of three factors analysis: material, thickness and morphology and temperature and humidity two test index.
Key words: thermal comfort; influencing factors; test index
1 office chair seat surface thermal comfort
1.1 to study the significance of thermal comfort of office chair seat
As the necessary furniture, the comfort level of the office chair greatly affects people's work and quality. The hot issue of the office chair and body close to the body is one of the most important factors in the evaluation of the seat comfort, which is most closely related to the skin of the human body. The respiratory function of the skin in a great extent by effects on the heat dissipation performance of office chair. If the office chair with temperature and humidity in the body's physiological function to adapt to bad will affect human thermal comfort, a long time will cause fatigue, but also a serious to suffer from skin diseases. This problem is particularly prominent in the summer, from a healthy and comfortable point of view, it is necessary to study the thermal comfort of the office chair seat. The scientific evaluation of office chair comfort can provide a very important theoretical basis for its design and manufacture. Therefore, how to design an office chair with good thermal comfort is becoming a hot topic in this field.
1.2 research status of thermal comfort of office chair seat
China on thermal comfort of the late start of the study, from the end of the 20th century began to human thermal comfort theory research, in recent years, many domestic and foreign scholars for seats thermal comfort evaluation methods do a lot of research
(1) Zhou Min et al in the hot seat comfort evaluation method, using the temperature of the probe thermometer in contact with the human body part of the seat, combined with test of subjective feelings, and the main and objective up comprehensive evaluation seat of thermal comfort performance.
(2) Zhuo Fu Liu, from the contact surface temperature properties of the model to extract the final temperature on contact surface, the contact surface temperature, the biggest change rate and contact surface average temperature three evaluation indexes is established according to the seat comfort evaluation system, use evaluation system of foam, die and a wooden seat three material seat are evaluated, results show that this evaluation system has certain reliability and practicability.
Test conditions (3) Lu Yuyi R & D the thermal sensation testing device, the device is composed of a copper cylinder and the thermal insulation layer is composed of two parts, the temperature sensation testing device to replace human beings in the, both save manpower, increase the safety, at the same time, it can also reduce the error caused by testing physiological and psychological differences, this device can be accepted widely, and continuous test and repeated experiments, the measurement results are stable and small error.
(4) Chenhao on car seat local cooling dehumidification was studied, analysis of the seat and the human body contact surface of high temperature and high humidity with fluid mechanics and heat transfer theory, according to the size of the body and car seat, the establishment of calculation model of automobile seats, numerical simulations were carried out using fluent software, the k-e model for solving temperature field and humidity field is selected, for the convenient of the automobile seat to make thermal comfort evaluation provides important theoretical basis.
Analysis on the influencing factors of thermal comfort of office chair seat 2
Influence seat surface thermal comfort factors there are many by office chair seat surface of the manufacture process and constitute the understanding, the main seat surface material, thickness, and seat surface form three aspects of sea surface thermal comfort. In which the main factor is the seat surface material, thermal conductivity, permeability and permeability is measure of material thermal comfort of important thermal physical parameters. Therefore, the study of seat surface of thermal comfort from the three aspects of.
2.1 base materials
The material of the seat surface can be divided into the base material and the base material. The common seat surface material cloth, mesh, leather etc.. And now there is a single splice seat surface, common cloth or leather and mesh surface splicing, thereby obtaining better thermal comfort. Commonly used material is a lot of foam, foam materials, mainly used in foam cotton, usually with a hardness of 70, the density of 30, 24, 16 of the foam cotton as a filling material. Different density will have a certain influence thermal comfort of the seat surface, the greater density of sponge, space is small, permeability and moisture permeability will relatively worse.
2.2 face thickness
Common office chair thickness within the scope of 5-15cm, general office chair and cloth thinner, cortical office chair thicker. In the summer, people tend to choose a more thin seat of the office chair, so the single network of office chairs more and more popular. In the study of thermal comfort, the main consideration filling material thickness, the same filling materials, larger thickness, the heat and moisture permeability of the worse, so the thermal comfort is worse.
2.3 surface morphology
The seat surface form of the existing office chair is more and more complex, and the shape of the seat surface of the chair of the leather is different. Changes in the shape of the seat surface can not only add extra points to the office chair, but also have a certain effect on thermal comfort. When people sit on different shapes of the seat surface, the contact area and the seat surface is different, the pressure distribution is different, so the temperature of the contact surface between the person and the seat will be different.
Three aspects of the above is from the angle of office chair on the thermal comfort influencing factors analysis, in order to better verify the influencing factors and thermal comfort in the relationship between, to be verified by the related objective test.
3 test of thermal comfort of office chair seat
To evaluation a chair seat surface has good thermal comfort, can not rely on subjective assessment of simple to obtain. There is also a need for the scientific test, can be tested from the two indices of the contact surface between the temperature and humidity. For the human body temperature and humidity are not separated. Studies have indicated that the body's thermal comfort depends largely on the body's skin temperature. Generally believe that the skin temperature reached 34 degrees Celsius, the body began to start sweating mechanism, through sweating to achieve thermal balance. Usually when the body temperature is kept in a very narrow range, the skin moisture content is low, and the body's physiological regulation of the most hours, people are in a state of thermal comfort. When people sit on the seat surface, the human body needs through the secretion of sweat to reach thermal equilibrium, the body needs to spread the heat more, that is, the secretion of sweat more, the last contact surface humidity is bigger. When the cooling effect of the seat surface is in good condition, the final humidity should be lower than the heat dissipation effect of the seat surface.
Through the experiment of people and the seat surface contact surface temperature and humidity for data collection, according to Bedford thermal comfort evaluation index and ASHRAE thermal sensation indices by their corresponding subjective evaluation is carried out, can be more accurate to office chair seat surface thermal comfort for evaluation.
4 concluding remarks
At home and abroad there are many evaluation on thermal comfort of the seat, but the office chair seat surface thermal comfort evaluation is relatively small, and mainly is to test the temperature, with little consideration given to the humidity on the thermal comfort effect. Often office chair discomfort mainly from humidity, temperature comfort often and humidity are closely linked, so you can will be comfortable temperature and humidity comfort combined to explore the office chair seat surface thermal comfort.
reference
[1] run Ping Niu, Chen Qizhen, Zhang Peihong. Thermal comfort research status and prospect [J]. Beijing: ergonomics, 2004, 10 (1): 38-40.
[2] Lu Jianxiong, Zhang Fuchang, Shen Liming. Ergonomic posture and seat design of [J]. ergonomics, 2005
[3] Ding Xiujuan, Hu Qinhua, Li Kuishan, et al. Research progress on thermal comfort of human body [J]. Dongguan: Journal of Dongguan University of Technology, 2007, 14 (1): 43-47.
[4] Zhou Min, Yang Yong. Thermal comfort of seat materials and its evaluation [J]. ergonomics, 2009, 15 (1): 28-30.
[5] Liu Zhuofu, Li Enhui, Li Junfu, et al. The objective evaluation of thermal comfort of the seat, the temperature model, the construction of [J]. ergonomics, 2012
Biography: Wang Meilan (1992-), female, Changshu Jiangsu people, work unit: Nanjing Forestry University School of furniture and industrial design, position: student, research direction: human engineering.