scholarly journals Perception of Thermal Comfort during Skin Cooling and Heating

Life ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 681
Author(s):  
Igor B. Mekjavic ◽  
Daniel Yogev ◽  
Urša Ciuha
Keyword(s):  
Thermal Comfort ◽  
Rate Of Change ◽  
Behavioral Regulation ◽  
Thermal Perception ◽  
Dynamic Activity ◽  
Heating And Cooling ◽  
Skin Cooling ◽  
Cutaneous Temperature ◽  
Cooling Phase ◽  
Temperature Stimulus

Due to the static and dynamic activity of the skin temperature sensors, the cutaneous thermal afferent information is dependent on the rate and direction of the temperature change, which would suggest different perceptions of temperature and of thermal comfort during skin heating and cooling. This hypothesis was tested in the present study. Subjects (N = 12; 6 females and 6 males) donned a water-perfused suit (WPS) in which the temperature was varied in a saw-tooth manner in the range from 27 to 42 °C. The rate of change of temperature of the water perfusing the suit (TWPS) was 1.2 °C min−1 during both the heating and cooling phases. The trial was repeated thrice, with subjects reporting their perception of the temperature and thermal comfort at each 3 °C change in TWPS. In addition, subjects were instructed to report when they perceived TWPS uncomfortably cool and warm during cooling and heating, respectively. Subjects reproducibly identified the boundaries of their Thermal Comfort Zone (TCZ), defined as the lower (Tlow) and upper (Thigh) temperatures at which subjects reported slight thermal discomfort. During the heating phase, Tlow and Thigh were 30.0 ± 1.5 °C and 35.1 ± 2.9 °C, respectively. During the cooling phase, the boundary temperatures of Tlow and Thigh were 35.4 ± 1.9 °C and 38.7 ± 2.3 °C, respectively. The direction of the change in the cutaneous temperature stimulus affects the boundaries of the TCZ, such that they are higher during cooling and lower during heating. These findings are explained on the basis of the neurophysiology of thermal perception. From an applied perspective, the most important observation of the present study was the strong correlation between the perception of thermal comfort and the behavioral regulation of thermal comfort. Although it is not surprising that the action of regulating thermal comfort is aligned with its perception, this link has not been proven for humans in previous studies. The results therefore provide a sound basis to consider ratings of thermal comfort as reflecting behavioral actions to achieve the sensation of thermal neutrality.

scholarly journals Heating and Cooling Degree-Days Climate Change Projections for Portugal

Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 715
Author(s):  
Cristina Andrade ◽  
Sandra Mourato ◽  
João Ramos
Keyword(s):  
Climate Change ◽  
High Resolution ◽  
Thermal Comfort ◽  
Energy Demand ◽  
Residential Buildings ◽  
Degree Days ◽  
Climate Change Projections ◽  
Heating And Cooling ◽  
Cooling Degree Days ◽  
Heating Energy Demand

Climate change is expected to influence cooling and heating energy demand of residential buildings and affect overall thermal comfort. Towards this end, the heating (HDD) and cooling (CDD) degree-days along with HDD + CDD were computed from an ensemble of seven high-resolution bias-corrected simulations attained from EURO-CORDEX under two Representative Concentration Pathways (RCP4.5 and RCP8.5). These three indicators were analyzed for 1971–2000 (from E-OBS) and 2011–2040, and 2041–2070, under both RCPs. Results predict a decrease in HDDs most significant under RCP8.5. Conversely, it is projected an increase of CDD values for both scenarios. The decrease in HDDs is projected to be higher than the increase in CDDs hinting to an increase in the energy demand to cool internal environments in Portugal. Statistically significant linear CDD trends were only found for 2041–2070 under RCP4.5. Towards 2070, higher(lower) CDD (HDD and HDD + CDD) anomaly amplitudes are depicted, mainly under RCP8.5. Within the five NUTS II

scholarly journals Optimization of Window Design for Daylight and Thermal Comfort in Cold Climate Conditions

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8013
Author(s):  
Tony-Andreas Arntsen ◽  
Bozena Dorota Hrynyszyn
Keyword(s):  
Thermal Comfort ◽  
Energy Demand ◽  
National Level ◽  
Cold Climate ◽  
Alternative Methods ◽  
Indoor Thermal Comfort ◽  
Heating And Cooling ◽  
Overall Performance ◽  
European Standards ◽  
Window Design

Window design affects the overall performance of a building. It is important to include window design during the initial stages of a project since it influences the performance of daylight and thermal comfort as well as the energy demand for heating and cooling. The Norwegian building code facilitates two alternative methods for achieving a sufficient daylight, and only guidelines for adequate indoor thermal comfort. In this study, a typical Norwegian residential building was modeled to investigate whether the criteria and methods facilitate consistent and good performance through different scenario changes and furthermore, how the national regulations compare to European standards. A better insulated and more air-tight building has usually a lower annual heating demand, with only a marginal decrease in the daylight performance when the window design is unchanged. A more air-tight construction increases the risk of overheating, even in cold climates. This study confirms that a revision of the window design improves the overall performance of a building, which highlights the importance of proper window design. The pursuit of lower energy demand should not be at the expense of indoor thermal comfort considering the anticipated future weather conditions. This study indicates that criteria for thermal comfort and daylight, if clearly defined, can affect the energy demand for heating and cooling, as well as the indoor climate positively, and should be taken into account at the national level. A comparison between the national regulations and the European standards was made, and this study found that the results are not consistent.

Some evidence of a time-varying thermal perception

2021 ◽  
pp. 1420326X2110345
Author(s):  
Marika Vellei ◽  
William O’Brien ◽  
Simon Martinez ◽  
Jérôme Le Dréau
Keyword(s):  
Thermal Comfort ◽  
Energy Savings ◽  
Thermal Environment ◽  
Thermal Conditions ◽  
Time Of Day ◽  
Time Varying ◽  
Thermal Perception ◽  
Indoor Thermal Environment ◽  
Human Circadian Rhythm ◽  
Comfort Criteria

Recent research suggests that a time-varying indoor thermal environment can lead to energy savings and contribute to boost buildings' energy flexibility. However, thermal comfort standardization has so far considered thermal comfort criteria as constant throughout the day. In general, very little attention has been given to the ‘ time of day' variable in the context of thermal comfort research. In this paper, we show some evidence of a time-varying thermal perception by using: (1) data from about 10,000 connected Canadian thermostats made available as part of the ‘ Donate Your Data' dataset and (2) about 22,000 samples of complete (objective + ‘ right-here-right-now' subjective) thermal comfort field data from the ASHRAE I and SCATs datasets. We observe that occupants prefer colder thermal conditions at 14:00 and progressively warmer ones in the rest of the day, indistinctively in the morning and evening. Neutral temperature differences between 08:00 and 14:00 and 14:00 and 20:00 are estimated to be of the order of 2°C. We hypothesize that the human circadian rhythm is the cause of this difference. Nevertheless, the results of this study are only based on observational data. Thermal comfort experiments in controlled environmental chambers are required to confirm these findings and to better elucidate the effects of light and circadian timing and their interaction on thermal perception.

scholarly journals Changes in the Distribution of Temperature in a Coal Deposit and the Composition of Gases Emitted during Its Heating and Cooling

2018 ◽  
Vol 10 (10) ◽  
pp. 3587 ◽  
Author(s):  
Marek Więckowski ◽  
Natalia Howaniec ◽  
Eugene Postnikov ◽  
Mirosław Chorążewski ◽  
Adam Smoliński
Keyword(s):  
Fire Hazard ◽  
Hot Spot ◽  
Measuring System ◽  
Hard Coal ◽  
Coal Deposit ◽  
Hazard Indices ◽  
Heating And Cooling ◽  
Cooling Phase ◽  
Percentage Share ◽  
The Given

This article presents the results of tests conducted on a measuring system for monitoring changes in the distribution of temperature in a coal deposit during the heating and cooling phases, and their correlation with the analysis of the concentration of gases. The tests were conducted on five samples of hard coal collected in deposits mined in Poland. Measurements of the changes in temperature and changes in gas concentration were conducted from the temperature of 35 to 300 °C, for the heating phase, and from 300 to 35 °C, for the cooling phase. The percentage share of coal of given temperatures was calculated. When comparing the percentage share for the same temperature in the hot spot, for the heating and cooling phase, significant differences in the distribution of the given percentages were observed. Changes in gas concentrations during heating and cooling were analyzed and the dynamics of changes in gas concentrations were determined for the coals tested. Changes in the values of fire hazard indices were analyzed. There were significant differences in the concentration of gases and the values of fire hazard indices between the heating and the cooling phase. The application of different criteria to assess coal during heating and cooling was proposed.

scholarly journals Thermal Perception in the Mediterranean Area: Comparing the Mediterranean Outdoor Comfort Index (MOCI) to Other Outdoor Thermal Comfort Indices

Energies ◽  
2016 ◽  
Vol 9 (7) ◽  
pp. 550 ◽  
Author(s):  
Iacopo Golasi ◽  
Ferdinando Salata ◽  
Emanuele de Lieto Vollaro ◽  
Massimo Coppi ◽  
Andrea de Lieto Vollaro
Keyword(s):  
Thermal Comfort ◽  
Mediterranean Area ◽  
Outdoor Thermal Comfort ◽  
Thermal Perception ◽  
Comfort Index ◽  
Outdoor Comfort ◽  
The Mediterranean ◽  
Comfort Indices

scholarly journals Thermal comfort evaluated for combinations of energy-efficient personal heating and cooling devices

2018 ◽  
Vol 143 ◽  
pp. 206-216 ◽  
Author(s):  
Maohui Luo ◽  
Edward Arens ◽  
Hui Zhang ◽  
Ali Ghahramani ◽  
Zhe Wang
Keyword(s):  
Thermal Comfort ◽  
Energy Efficient ◽  
Heating And Cooling ◽  
Cooling Devices

scholarly journals Effect of flow rates of gases flowing through a coal bed during coal heating and cooling on concentrations of gases emitted and fire hazard assessment

2019 ◽  
Vol 7 (1) ◽  
pp. 107-121 ◽  
Author(s):  
Marek Więckowski ◽  
Natalia Howaniec ◽  
Adam Smoliński
Keyword(s):  
Fire Hazard ◽  
The Self ◽  
Coal Bed ◽  
Flow Rates ◽  
Coal Beds ◽  
Heating And Cooling ◽  
Heating Phase ◽  
Two Samples ◽  
Cooling Phase ◽  
Phase Temperature

AbstractThe flow velocity of gases in gobs directly influences the kinetics and intensity of gaseous components release during heating and cooling of coal. The assessment of fire hazard is performed on the basis of concentrations of particular gases in a mine air. These concentrations differ in coal heating and cooling phase which was proven in the study. This paper presented the results of the experimental study on temperature distribution in a simulated coal bed in heating (50–250 °C) and cooling (250–35 °C) phases as well as its correlation to variations in concentration of gases released in these phases and flow rates of gases flowing through the coal bed. The research was performed on twenty-two samples of bituminous coals acquired from various coal beds of Polish coal mines. Considerable differences were observed between heating and cooling phases in terms of the concentrations of gases taken into account in calculations of self-combustion index. In the heating phase temperature increase resulted in the decrease of concentrations ratios of ethane, ethylene, propane, propylene and acetylene, while in the cooling phase these ratios increased systemically. The effect of air (in heating phase) and nitrogen (in cooling phase) flow rate on the self-ignition index CO/CO2 was also determined.

scholarly journals Assessing the indoor thermal comfort of a toll station

2019 ◽  
Vol 282 ◽  
pp. 02031
Author(s):  
Ricardo M.S.F. Almeida ◽  
Eva Barreira ◽  
Sandra Soares ◽  
Ramos Nuno M.M. ◽  
Sérgio Lopes ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Indoor Environment ◽  
Thermal Sensation ◽  
Physical Parameters ◽  
Indoor Environmental Quality ◽  
Thermal Perception ◽  
Health And Wellbeing ◽  
Local Thermal Comfort ◽  
Toll Station ◽  
Global And Local

The importance of a good indoor environment for peoples’ health and wellbeing is nowadays clearly established. Besides enhancing the wellbeing of building occupants and helping decrease the occurrence of building related illness, a good indoor environment can also lead to a decrease in worker complaints and absenteeism. This paper presents the results of a three-month monitoring campaign where the thermal comfort of a toll station was evaluated, including the main room and the cabins. The physical parameters required for the assessment of both global and local thermal comfort were measured and the results were compared with the thermal perception of the occupants, which was collected through questionnaires. The indoor environmental quality in the main room was better than in the cabins and a mismatch between the PMV index and the occupants thermal sensation was identified.

scholarly journals Optimization of building form and its fenestration in response to microclimate conditions of an urban area

2020 ◽  
Vol 172 ◽  
pp. 19002
Author(s):  
Kavan Javanroodi ◽  
Vahid M. Nik ◽  
Yuchen Yang
Keyword(s):  
Thermal Comfort ◽  
Urban Area ◽  
Urban Areas ◽  
Energy Demand ◽  
High Performance ◽  
Weather Conditions ◽  
Climate Data ◽  
Heating And Cooling ◽  
Building Form ◽  
Microclimate Conditions

Designing building form in urban areas is a complicated process that demands considering a high number of influencing parameters. On the other hand, there has been an increasing trend to design highly fenestrated building envelopes for office buildings to induce higher levels of natural lighting into the workspace. This paper presents a novel optimization framework to design high-performance building form and fenestration configuration considering the impacts of urban microclimate in typical and extreme weather conditions during a thirty-year period of climate data (2010-2039). In this regard, based on the introduced technique and algorithm, the annual energy demand and thermal comfort of over 8008 eligible form combinations with eight different fenestration configurations and seven different building orientation angels were analysed in a detailed urban area to find optimal design solutions in response to microclimate conditions. Results showed that adopting the framework, annual heating, and cooling demand can be reduced by 21% and 38% while maintaining thermal comfort by taking design-based decisions at the early stages of design.

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