A large proportion of energy consumption in Japan is attributable to houses, and that of household appliances is not negligible. However, as the Energy Conservation Act in Japan does not cover ...household appliances such as electric heating devices, sufficient measures for energy saving of household appliances are not provided. In this study, by analyzing HEMS (home energy management system) data, we have surveyed the power consumption of electric heating devices, bathroom heaters, and other appliances in recently built houses in Tokyo and Kanagawa prefectures. In addition, we have estimated the effect of equipment replacement into high-efficiency ones.
It has been proven that local heating can satisfy the thermal comfort needs of people with low energy consumption. Previous research on local heating equipment has been conducted in artificial ...climate chambers rather than in naturally conditioned buildings. In this study, a four-sided enclosed local heating device was developed, and experiments were conducted to investigate the thermal comfort and corresponding energy consumption when 20 subjects (half male and half female) used this device in a naturally conditioned environment in winter (12–16 °C). The experimental results indicated that the overall thermal responses of the subjects stabilized after the local heating device was used for 15 min, which significantly improved the overall thermal responses of the subjects (p < 0.01); furthermore, female subjects preferred a warmer environment. The upper limbs and shanks had the most intense cold sensations in the upper and lower body, respectively. Compared with the condition without local heating, the difference in body temperature of the shank was significant (p < 0.01). In addition, the total heating power of the equipment was related to the number of heating plates turned on. The fitting results indicated that the thermoneutral temperatures when three and four heating plates were turned on were 15.7 °C and 13.5 °C, respectively. The study results contributed to providing a reference for solving heating problems in areas where there were no central-heating facilities.
•A four-sided enclosed local heating device used in human lower body.•Human experimentation in a naturally conditioned room.•The performance of a four-sided enclosed local heating device was quantitatively evaluated.•The gender differences in human thermal responses were analyzed.
•GNP and MWCNT collectively affect mechanical stability and electrical property of the PFHD.•Optimized PFHD contains 67 wt% MWCNT and 33 wt% GNT.•Paper-based low cost and rapid heating device shows a ...Tmax of 116.3 ℃ at 2.5 V.•Flexible and lightweight heating device ideal for PEMFC driven aerial vehicle can serve as a disposable container for hydrogen fuel.
A paper-based flexible heating device (PFHD - paper-based flexible heating device) composed of a cellulose paper substrate and a carbonaceous functional electrode is reported. The functional composite electrodes containing graphene nanoplatelets (GNP - graphene nanoplatelets) and multi-walled carbon nanotubes (MWCNT) in various compositional ratios were prepared by dip-coating the oxygen plasma-treated paper substrate into the composite ink, and subsequently dried at 110 ℃ for 30 min to prepare PFHDs. The electrochemical characteristics and heat generation properties of PFHDs indicated that the GNP component in the functional electrode enhanced the electrical conductivity of the electrode, and the physical stability was enhanced mainly by the MWCNT component. Accordingly, PFHD0.33 which contains 33 % GNP and 67 % MWCNT in the functional electrode shows excellent heating performance with high stability and areal rated power of 0.68 W cm−2 (specific rated power = 45 W g−1). The measured sensitivity of PFHD0.33 is 31.50 ℃ V−1 at the applied DC voltage of 0.1–2.0 V.
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Perioperative hypothermia is a common anesthesia-related complication that can result in negative outcomes. Intraoperative active heating can positively impact these outcomes. Therefore this study ...aimed to investigate the effectiveness of three common heating devices for controlling hypothermia, improving thermal comfort, and reducing anesthesia recovery time.
Systematic review and meta-analysis.
Seven electronic literature databases were searched from the inception date of the databases to March 18, 2022. RevMan 5.4 and Stata 15.1 were used to perform meta-analyses on the obtained data, and the Cochrane Evaluation Manual was used for quality risk assessment of the included studies.
A total of 18 studies involving 1,511 patients undergoing surgery using heating devices were included. In this meta-analysis, a ranking method known as the Surface Under the Cumulative Ranking Curve (SUCRA) was used. SUCRA provides a numerical measure of the effectiveness of treatments, with higher values indicating superior efficacy. Findings demonstrated that the concurrent use of three heating devices led to an elevation in core body temperatures (SUCRA = 69.2%) and enhanced delayed recovery (SUCRA = 88.6%) as compared to the application of a single device. Furthermore, for thermal comfort, the employment of heating blankets proved to be the most effective (SUCRA = 87.8%).
This study showed the core body temperatures and reductions in delayed recovery were greater when three heating devices were used together as compared to use one of them alone. Heating blankets was the most effective option for improving the thermal comfort of patients. Thus, clinicians should opt for appropriate heating equipment according to the type of surgery and the characteristics and needs of patients. The choice of appropriate heating equipment will ensure surgical safety, improve patient comfort, and reduce surgical risks.
This study reports a newly designed induction heating system for efficient, fast, and safe flow-through heating. The system has a very simple architecture, which is composed of a transmitting coil, ...an isolating plastic pipe, and an embedded metal shell. Wireless energy transfer from the external coil to the internal metal shell through the pipe is essential for decreasing losses. Also, a large contact surface between a fluid and the immersed shell enables rapid heat transfer. The proposed heating system was systematically investigated for different shell geometries and the results were compared with a commercially available conductive flow-through heating device. As a proof-of-concept demonstration, a prototype of the designed induction heating system was manufactured and the heating measurements were conducted with water. Power transfer efficiency of the prototyped induction heating system was measured to be 97%. The comparative study indicates that such high-efficiency induction flow-through heating system offers a great potential for replacing the conventional conductive heating device used in household applications in which the rapid and compact heating is desired.
Riveted joint is one of the joining methods for steel structures, but the JIS standard for rivets has been abolished at present, and it is impossible to use the conventional SV standard. Therefore, ...authors developed riveted joint by a new method using SNR400B. This paper reports on the results of material tests conducted using the SNR400B and the inspections and construction flow that were carried out to ensure construction quality when applying revets to actual buildings.
This paper proposes the use of superhydrophobic graphene/ceramic templates fabricated through laser texturing and patterning for the preparation of particulate drugs. A nanosecond pulse fiber laser ...was used to texture a graphene film coated on ceramic substrates for obtaining a superhydrophobic surface. Then, laser patterning was conducted on the laser-textured surface to define the diameter of the prepared particulate drugs. Laser-textured graphene/ceramic substrates with a laser areal fluence of 17.51 J/cm2 and a hatch distance of 0.01 mm exhibited a maximum water contact angle of 151.5°. This result was obtained because the laser-textured graphene films contained coral reef structures with nanoscale pores. Raman analyses indicated that the intensities of the G and 2D bands gradually decreased after the laser texturing and patterning processes. Moreover, the sheet resistance of the laser-textured and laser-patterned graphene films was larger than that of untextured ones because the thickness of the graphene films was reduced through laser thinning. The maximum heating temperature of the graphene-based heater was 140 °C for an input direct current voltage of 36 V. In addition, graphene-based self-heating devices were developed and successfully used to dry liquid roflumilast.
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•A facile electrospinning approach of composite nanofibers was presented.•Self-heating conductive conjugated PVA-G composite nanofibers.•G sheets dispersion within the nanofibers were ...proposed.•Characteristics of PVA-G nanofibers in electrical and thermal abilities were discussed.•On-chip device surface for humidity detection was demonstrated.
In this study, we measured the performance of self-heating conductive conjugated polyvinyl alcohol, (PVA)/graphene (G) composite nanofibers in the detection of environmental humidity. PVA-G polymer nanocomposite fibers were electrospun together from suspensions of PVA and varying concentrations of pristine G sheets. The extent of graphene dispersion in the nanocomposite fibers were characterized via Raman and transmission electron microscopy (TEM) analysis. Where the main content of C and O elements in composite nanofibers were obtained from the energy dispersive (EDX) spectra and EDX mapping results. Thermal characteristics and structural morphology were then investigated through thermal gravimetric analysis (TGA), and focused ion beam scanning electron microscopy (FIB-SEM) & laser scanning confocal microscopy (LSCM), respectively. Applied voltages (0−10 V) to the PVA-G polymer nanocomposite fibers under varying conditions of humidity were investigated. With increasing concentration of G, increased sensitivity to relative humidity could be observed through the proportional changes in resistance. In addition, at PVA-G concentrations at 6%, the tested humidity sensor remained highly responsive while operating at low temperatures of 60 °C and with minimal power consumption.
•The heat flux control method can promptly provide personalized thermal comfort regulation.•A model is developed to determine the heat transfer mechanism in human-clothing-ambient system.•Three ...temperature sensors are used in the heat flux control system to establish the heat exchange equation.•Temperature and sensible heat loss can be steadily controlled within thermal comfort standard.•Wearable heating device is used to demonstrate the reliability and practicality of the model.
In this study, a thermal comfort control model based on heat flux regulation was developed to ensure the thermal comfort in human-clothing-environment system. Compared to traditional temperature control methods, the heat flux control method in this study provided a more stable control for both temperature and heat flux, and clearly quantified human thermal sensation under cold stress. First, a heat transfer model was derived to quantitatively describe the heat transfer of an electrically heating device between two fabric layers. By using three temperature sensors, the mathematical description of derived heat exchange equation was validated and applied to a wearable heating device. The scenarios of a person in cold environments and under various activity levels were also simulated by using an environmental chamber. A control strategy based on the mathematical model was developed to optimize the applied voltage of the electric heater. The skin temperature and sensible heat loss can be stably controlled within standard thermal comfort range (Predicted Mean Vote ~ 0). Finally, an example of human wearing an electrically heated jacket in the freezer room was used to demonstrate the reliability and practicality of the heat flux control system.
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The article deals with the optimization of circuit solutions and operational parameters in order to increase the efficiency of solar heat supply systems equipped with flat solar collectors. The ...development of innovative technologies for the use of solar energy in the country, increasing its efficiency, as well as the development of scientific research in this area, including the formation of skills and a broad understanding of the use of solar energy, a laboratory bench was provided for monitoring internal processes in information systems. Current use of these methods has seen electrical heating of solar collectors, the use of antifreeze, the use of slow circulation, drainage and high energy costs.
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