PROVIDING THERMAL COMFORT OF THE DISTAL SEGMENTS OF THE LOWER LIMBS BY USING AN AUTONOMOUS ELECTRIC HEATING SYSTEM

2021 ◽  
Author(s):  
I.S. Malakhova ◽  
◽  
T.K. Losik ◽  
O.V. Burmistrova
Keyword(s):  
Thermal Comfort ◽  
Thermal Insulation ◽  
Low Temperatures ◽  
Electric Heating ◽  
Heating System ◽  
The Body ◽  
Climatic Zone ◽  
Experimental Sample ◽  
Local Cooling ◽  
Additional Heat

Abstract. Introduction. Work in low temperatures can lead to both general and local cooling of the human body. Local cooling of the distal parts of the legs can limit the motor activity of the employee even with sufficient thermal insulation of the body general surface. Therefore, the use of an additional heat source in special shoes (autonomous electric heating system (AEHS)) can compensate heat losses in the distal parts of the legs and provide thermal comfort in conditions of low temperatures throughout the work. The purpose of the study: physiological and hygienic assessment of the additional heat sources (AEHS) influence on the thermal insulation of special shoes in conditions of low temperatures. Materials and methods. To assess the heat-protective properties of the special shoes experimental sample with an AEHS, a heat flux density and skin temperature meter ITP-MG 4.03/30 "POTOK" (LLC SKB Stroypribor, Chelyabinsk) was used. The presented sample was tested with the participation of 5 volunteers in three modes of autonomous electric heating in a microclimatic chamber for 60 minutes for each mode separately. The average air temperature in the chamber during the study was 2.5±0.5 °C. Based on the obtained data, the thermal insulation of special shoes with an AEHS was calculated. Results. The thermal insulation of the special shoes experimental sample without electric heating was 0.460±0.013 °C m2/W; and 0.512±0.01 and 0.549±0.01 °C m2/W using the minimum and medium electric heating modes-, respectively, which allows us to recommend the presented sample of special shoes with an autonomous electric heating system for work in a "Special" climatic zone when performing moderate-severity work. The thermal insulation of a special shoes sample with the maximum electric heating mode was 0.615±0.01 °C m2/W, which makes it possible to work with it in the IV climatic zone. Conclusions. The use of an AEHS increases the thermal insulation of special shoes, which provides sufficient protection for the distal parts of the legs, allows to expand the scope of its operation in strict compliance with the work and rest regime and can be a prevention of the occupational diseases development in workers at low temperatures.

scholarly journals Field Study Of A Radiant Heating System For Sleep Thermal Comfort And Potential Energy Saving

2021 ◽  
Author(s):  
Christopher L. K. Wang
Keyword(s):  
Potential Energy ◽  
Thermal Comfort ◽  
Energy Saving ◽  
Energy Savings ◽  
Thermal Environment ◽  
Residential Buildings ◽  
Thermal Conditions ◽  
Heating System ◽  
The Body ◽  
Radiant Temperature

As sleep is unconscious, the traditional definition of thermal comfort with conscious judgment does not apply. In this thesis sleep thermal comfort is defined as the thermal condition which enables sleep to most efficiently rejuvenate the body and mind. A comfort model was developed to stimulate the respective thermal environment required to achieve the desired body thermal conditions and a new infrared sphere method was developed to measure mean radiant temperature. Existing heating conditions according to building code conditions during sleeping hours was calculated to likely overheat a sleeping person and allowed energy saving potential by reducing nighttime heating set points. Experimenting with existing radiantly and forced air heated residential buildings, it was confirmed that thermal environment was too hot for comfortable sleep and that the infrared sphere method shows promise. With the site data, potential energy savings were calculated and around 10% of energy consumption reduction may be achieved during peak heating.

Effects of Clothing Ventilative Designs on Thermal Insulation under Varying Wind Conditions

2011 ◽  
Vol 332-334 ◽  
pp. 1927-1930 ◽  
Author(s):  
Xiang Hui Zhang ◽  
Jun Li
Keyword(s):  
Experimental Investigation ◽  
Thermal Comfort ◽  
Thermal Insulation ◽  
The Body ◽  
Thermal Manikin ◽  
Clothing Insulation ◽  
Vertical Side ◽  
Wind Velocities ◽  
Heat And Moisture ◽  
Body Heat

This paper reports on an experimental investigation of the effects of clothing ventilative designs on thermal comfort measured in terms of thermal insulation. Eight T-shirts with varying areas and locations of mesh fabric were designed and produced for testing on a dry thermal manikin. Clothing thermal insulation of T-shirts was measured under three wind velocities: 0.5, 1 and 2m/s. The results showed that, the areas and locations of ventilation panels affect the total thermal insulation. The T-shirts with larger area of mesh fabric are preferable in terms of releasing more body heat. Among various designs tested, mesh fabrics applied at two vertical side seams can most effectively release heat and moisture from the body. Clothing insulation is also greatly affected by wind.

Impact of electrical heating on effective thermal Insulation of a multi-layered winter clothing system for optimal heating efficiency

2016 ◽  
Vol 28 (2) ◽  
Author(s):  
Huiju Park ◽  
Soo-kyung Hwang ◽  
Joo-Young Lee ◽  
Jintu Fan ◽  
Youngjin Jeong
Keyword(s):  
Ambient Temperature ◽  
Heat Loss ◽  
Thermal Insulation ◽  
Electric Heating ◽  
The Body ◽  
Electrical Heating ◽  
Thermal Manikin ◽  
Heating Unit ◽  
Heating Efficiency ◽  
Body Heat

Purpose This paper investigated the impact of the distance of the heating unit from the body in a multi-layered winter clothing system on effective thermal insulation and heating efficiency. Design/methodology/approach To identify changes in the thermal insulation and heating efficiency of electrical heating in different layers inside a winter clothing ensemble, a series of thermal manikin tests was conducted. A multi-layered winter ensemble with and without activation of a heating unit was tested on the thermal manikin under two different ambient temperature conditions (10°C and -5°C). Findings Results show that the effective thermal insulation of test ensembles increased by 5-7% with the activation of the heating unit compared to that without the activation. The closer the heating unit to the body, the higher the effective thermal insulation was in both ambient temperature conditions. This trend was more significant at lower ambient temperature. Research limitations/implications The results of this study indicate that providing electric heating next to the skin is the most effective in increasing effective thermal insulation and decreasing body heat loss in both ambient temperature (-5°C and 10°C). This trend was more remarkable in colder environment at -5°C of ambient temperature as evidenced by sharp decrease in heating efficiency and effective thermal insulation with an increase in distance between the manikin skin and heating unit at -5°C of ambient temperature compared to at 10°C of ambient temperature. Practical implications Based on the results, it is expected that proximity heating next to the skin, in cold environment, may reduce the weight and size of the battery for the heating unit because of the higher efficiency of electric heating and the potentially immediate perception of warmth supported by the greatest increase in effective thermal insulation, as well as the lowest heat loss that comes with activation of heating on the first layer in cold environment. Originality/value The finding of this study provides guidelines to sportswear designers, textile scientists, sports enthusiasts, and civilians who consider electric heating benefits for improved thermal comfort and safety in cold environments, especially in the areas of outdoor and winter sports and in military service. The results of this study indicate that providing electric heating next to the skin is the most effective in increasing effective thermal insulation and decreasing body heat loss in both ambient temperature (-5°C and 10°C).

Demand Side Electric Energy Consumption Optimization in a Smart Household Using Scheduling and Model Predictive Temperature Control

2021 ◽  
Vol 143 (6) ◽  
Author(s):  
Salma Taik ◽  
Bálint Kiss
Keyword(s):  
Thermal Comfort ◽  
Electric Heating ◽  
Heating System ◽  
Comfort Level ◽  
Mixed Integer ◽  
Programming Approach ◽  
Input Constraints ◽  
Optimization Strategy ◽  
Residential Areas ◽  
Energy Consumption Optimization

Abstract Utility companies seek to increase energy efficiency and productivity and try to reduce peak loads. This often involves consumer-side demand management in residential areas using dynamic time-of-use (ToU) tariff. Such strategies work if the consumer-side response is at least partly automated using some real-time optimization strategy. Our paper proposes a consumer-side optimization and control framework for scheduling the electric appliances in a smart household and preserving a thermal comfort level through an electric heating system. Our framework consists of two optimization components interacting with each other. The first optimization component schedules the home appliances based on a mixed integer programming approach. An electric vehicle (EV) is considered as a special home appliance with an energy storage capability. The second optimization component is the model predictive control (MPC) strategy for the electric heating system, such that the input constraints are defined by the scheduling results of the first component. Due to outside temperature variations, the input constraints may impede the MPC to maintain the required thermal comfort, which triggers a rescheduling event for the first component. The efficiency of the framework is presented in multiple simulations for scenarios with different consumer behaviors.

Comparison of clothing thermal comfort properties measured on female and male sweating manikins

2016 ◽  
Vol 87 (18) ◽  
pp. 2214-2223 ◽  
Author(s):  
Chao Sun ◽  
Jintu Fan
Keyword(s):  
Thermal Comfort ◽  
Heat Loss ◽  
Thermal Insulation ◽  
Female Body ◽  
Body Shape ◽  
The Body ◽  
Thermal Manikin ◽  
Unit Surface Area ◽  
Evaporative Resistance ◽  
Evaporative Water

Thermal manikins simulating human body’s thermal regulatory system are essential tools for understanding the heat exchange between human body and the environment and also for evaluating the thermal comfort of clothing and near environment. However, most existing thermal manikins adopt a male’s body shape and no sweating female thermal manikin has been reported so far. Furthermore, it is unclear how body shape (viz. male vs female) affects the heat loss and perspiration from the body. We report on a novel female sweating thermal manikin “Wenda”. Thermal properties of the nude body and clothing ensembles measured on “Wenda” are compared with those measured on the male manikin “Walter”. It was found that, although the more curvaceous female body reduces the thermal insulation of the nude manikin, it increases the apparent evaporative resistance at the same time. This may be due to the fact that the more curvaceous female body increases the surface still air layer to add resistance to heat loss by conduction and evaporative water loss by diffusion, and significantly increases the percentage of effective radiative area and the resultant radiative heat loss per unit surface area. It was further shown that clothing thermal insulation and apparent evaporative resistance measured on Wenda are typically 0 ∼ 11% higher than those measured on the male sweating fabric manikin-Walter, probably due to the greater clothing microclimate volume on the female manikin resulting from the looser fitting of the garments on the smaller female body and the more curvaceous surface of the female body.

scholarly journals Field Study Of A Radiant Heating System For Sleep Thermal Comfort And Potential Energy Saving

2021 ◽  
Author(s):  
Christopher L. K. Wang
Keyword(s):  
Potential Energy ◽  
Thermal Comfort ◽  
Energy Saving ◽  
Energy Savings ◽  
Thermal Environment ◽  
Residential Buildings ◽  
Thermal Conditions ◽  
Heating System ◽  
The Body ◽  
Radiant Temperature

As sleep is unconscious, the traditional definition of thermal comfort with conscious judgment does not apply. In this thesis sleep thermal comfort is defined as the thermal condition which enables sleep to most efficiently rejuvenate the body and mind. A comfort model was developed to stimulate the respective thermal environment required to achieve the desired body thermal conditions and a new infrared sphere method was developed to measure mean radiant temperature. Existing heating conditions according to building code conditions during sleeping hours was calculated to likely overheat a sleeping person and allowed energy saving potential by reducing nighttime heating set points. Experimenting with existing radiantly and forced air heated residential buildings, it was confirmed that thermal environment was too hot for comfortable sleep and that the infrared sphere method shows promise. With the site data, potential energy savings were calculated and around 10% of energy consumption reduction may be achieved during peak heating.

scholarly journals Circadian winter thermal profiles and thermal comfort in historical housing — field study

2021 ◽  
Vol 2069 (1) ◽  
pp. 012081
Author(s):  
M Baborska-Narożny ◽  
M Laska ◽  
N Fidrów-Kaprawy ◽  
M Malyszko
Keyword(s):  
Thermal Comfort ◽  
Field Study ◽  
Thermal Environment ◽  
Local Heating ◽  
Electric Heating ◽  
Heating System ◽  
Time Of Day ◽  
Structured Interviews ◽  
Central Heating ◽  
The Cost

Abstract In winter thermally inefficient building envelopes of pre-retrofit historical housing allow for ca. sevenfold higher heat loss from heated apartments than the new built housing in Poland. As a result space heating in pre-retrofit tenements is regarded to be highly energy demanding and costly if the internal temperatures were to be kept on average at standard 20 °C assumed in building regulations. In this field study, carried out in January-March 2020, we investigated circadian thermal profiles and the associated thermal comfort in historical tenements both pre-and post-retrofit. The 16 apartments participating in our research were equipped with heating systems prevalent in Polish urban historical buildings, i.e. solid fuel stoves, electric heating, district-supplied central heating, or individual gas boilers. The former systems provided intermittent local heating while the latter central heating with thermostats. Our research comprised spot check multi-parameter measurements and continuous monitoring of the thermal environment, together with a longitudinal thermal comfort questionnaire survey (N=.2539), energy consumption analysis and semi-structured interviews with the residents. The differences detected in average (12.6°C) and range (up to 5.0°C) of diurnal temperatures did not explain the thermal comfort survey results on individual thermal sensations and preferences. What proved more important for the residents was the time of day when the maximum or minimum temperatures occurred and their perceived control over temperature and the cost associated with heating. Accordingly, we identified a need for further studies investigating the link between domestic thermal comfort and satisfaction with the usability of the heating system and control over the cost of heating.

scholarly journals The Effect Of Thermal Insulation Of An Apartment Building On The Thermo-Hydraulic Stability Of Its Heating System

2015 ◽  
Vol 23 (4) ◽  
pp. 8-18
Author(s):  
Mária Kurčová
Keyword(s):  
Thermal Comfort ◽  
Thermal Insulation ◽  
Thermal Characteristics ◽  
Heating System ◽  
Apartment Building ◽  
Hydraulic Stability

Abstract The contribution aims to investigate the effect of the decreased thermal losses of an apartment building due to the thermal insulation of opaque external building constructions and the replacement of transparent constructions. It emphasizes the effect of the thermal characteristics of external constructions on the functionality of the existing heating system in the building and the related requirements for the renovation of the heating system in order to ensure the hydraulic stability of the system and the thermal comfort of the inhabitants.

scholarly journals Development of a simulation model of the heating process in the passenger cabin of a vehicle under low temperature conditions

2021 ◽  
Vol 18 (5) ◽  
pp. 510-523
Author(s):  
D. A. Aleshkov ◽  
M. V. Banket ◽  
M. V. Sukovin
Keyword(s):  
Thermal Comfort ◽  
Low Temperatures ◽  
Heating System ◽  
The Arctic ◽  
Theoretical Studies ◽  
Passenger Compartment ◽  
Wheeled Vehicle ◽  
The Impact ◽  
Wheeled Vehicles ◽  
Passenger Cabin

Introduction. A distinctive feature of working conditions in the Arctic territories is the long period of exposure to low temperatures. Passenger transportation by road is becoming one of the key aspects of ensuring the continuity of the production process. The task of delivering workers to the place of work, moving them between work zones during a work shift is solved by using wheeled vehicles of various categories. One of the most widespread types of wheeled vehicles used to transport workers is the M3 category wheeled vehicles with a capacity of no more than 22 passengers. Ensuring the thermal comfort of vehicle passengers seems to be relevant, since ensuring biophysical compatibility minimizes the risks of cold injury by workers and maintains a high level of performance.Materials and methods. The results of the analysis of the Russian and foreign studies in the direction of ensuring thermal comfort and ensuring biophysical compatibility in confined spaces are presented. The results of computer modelling of the dynamics of microclimate parameters in the passenger cabin of a wheeled vehicle of M3 category with a capacity of no more than 22 passengers are presented.Results. The paper presents the results of theoretical studies, microclimate parameters in the passenger compartment of vehicles, taking into account the breathing of passengers and changes in the gas composition of exhaled air. Theoretical studies of the operation of the heating system of the passenger compartment were carried out, taking into account the refined breathing model of passengers. Distributions of microclimate parameters in the section of the passengercompartment were obtained when using a heating system with one heater; the impact of passengers’ breathing on the parameters of the microclimate in the passenger compartment was assessed.Discussion and conclusion. Based on the numerical solution of the system of heat transfer equations, directions for further research and recommendations are formulated to ensure thermal comfort in the passenger compartment of a wheeled vehicle at low temperatures. The materials of the work may be of interest to specialists involved in the design and ergonomics of wheeled vehicles, labor protection.

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