scholarly journals Thermal Comfort Aspects of Solar Gains during the Heating Season

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1702 ◽  
Author(s):  
Ferenc Kalmár ◽  
Tünde Kalmár
Keyword(s):  
Thermal Comfort ◽  
Energy Use ◽  
Winter Season ◽  
Diffuse Radiation ◽  
Heating Season ◽  
Negative Effects ◽  
Thermal Discomfort ◽  
Wet Bulb Globe Temperature ◽  
Globe Temperature ◽  
Personalized Ventilation

Glazing plays a key role in the energy balance of buildings. The aim of this paper is to enlighten the thermal discomfort caused by large glazed areas in the heating season and to point out a possible solution that can provide proper thermal comfort with low energy use. It is unusual to discuss the negative effects of solar gains on thermal comfort during the heating season. However, there are cases when glazing may lead to unforeseen indoor thermal discomfort conditions. Laboratory and on site measurements were performed in order to assess thermal discomfort caused by direct and diffuse radiation. It was shown that the WBGT (Wet Bulb Globe Temperature) index may exceed even 30 °C in the winter season in a room having large glazed area oriented to east. Laboratory tests performed in climate chamber have shown that the high PMV values cannot be reduced below 1.0, increasing the air change rate in the room. Using opaque drapes, the WBGT index was reduced by 2 °C, but the daylighting decreased substantially. It was demonstrated that by using advanced personalized ventilation systems, the appropriate thermal comfort can be provided avoiding the reduction of daylighting.

scholarly journals Numerical evaluation of thermal discomfort in conditions of surface heating and asymmetric radiation

2018 ◽  
Vol 9 (2) ◽  
pp. 175-179
Author(s):  
F. Kalmár ◽  
T. Kalmár
Keyword(s):  
Thermal Properties ◽  
Thermal Comfort ◽  
Winter Period ◽  
Negative Effects ◽  
Air Velocity ◽  
Thermal Discomfort ◽  
External Wall ◽  
Wall Heating ◽  
Personalized Ventilation ◽  
Radiant Temperature

This paper presents the results of analytical analysis of thermal comfort and radiation asymmetry in case of wall heating depending on the room geometry and thermal properties of the external wall. The negative effects of radiation asymmetry on thermal comfort in case of summer conditions can be lowered using advanced personalized ventilation systems. In case of buildings with poor thermal properties of the envelope during the winter period low surface temperatures may occur. The aim of this research was to analyse the thermal asymmetry in the case of a room with one external wall and wall heating installed on the opposite wall. It was assumed that the radiation asymmetry will lead to discomfort and it was hypothesised that the discomfort might be reduced increasing the air velocity. The results have proven that thermal asymmetry in the middle of the room will not lead to thermal discomfort even for walls without any additional thermal insulation. However, the mean radiant temperature varies significantly depending on the position of the occupant in the room. In this case, the personalized control on the air velocity can help to improve the thermal comfort conditions.

scholarly journals Thermal performance and concentration of gases in facilities for pigs in semiarid region from State of Paraiba - Brazil

2012 ◽  
Vol 32 (1) ◽  
pp. 30-37 ◽  
Author(s):  
Dermeval A. Furtado ◽  
Daniele Amancio ◽  
José W. B. do Nascimento ◽  
Josivanda P. Gomes ◽  
Rafael C. Silva
Keyword(s):  
Carbon Monoxide ◽  
Thermal Comfort ◽  
Rainy Season ◽  
Dry Season ◽  
International Standards ◽  
Semiarid Region ◽  
Thermal Discomfort ◽  
Rainy Period ◽  
Globe Temperature ◽  
The Times

The study was conducted in a facility for pigs during the nursery and finishing in the town of 'Montadas', in the semiarid of the state of Paraiba, Brazil, in the rainy and dry season, aiming to evaluate the concentration of oxygen, methane, carbon monoxide and ammonia, and the bioclimatic indexes: ambient temperature (AT), relative humidity (RH) and the index of black globe temperature and humidity (IBGTH). These indexes differed significantly (P>0.05) between the periods and times. The AT in the rainy season was in the thermal comfort zone(TCZ) in most of the times in the nursery; for the finishing phase, thermal discomfort occurred; during the dry season, there was thermal comfort in the nursery phase; in the finishing phase the thermal discomfort occurred at all times. In the rainy season, the IBGTH was in TCZ; in the dry season, it was above the TCZ. The RH in the rainy period was in the TCZ; in the dry season, in most of the times, below the range of the TCZ. The concentration of gases showed no differences (P > 0.05) between periods and between the times, and the carbon monoxide, hydrogen sulfide and methane were below 1.0 ppm, and the ammonia showed a mean of 5.2 ppm. None of the analyzed gases exceeded the limits established by Brazilian and international standards for animals and workers.

Evaluation of Indoor Climate in Small University Lecture Hall

2016 ◽  
Vol 861 ◽  
pp. 369-375
Author(s):  
Mária Budiaková
Keyword(s):  
Thermal Comfort ◽  
Architectural Design ◽  
Winter Season ◽  
Lecture Hall ◽  
Experimental Measurements ◽  
Optimal Parameters ◽  
Indoor Climate ◽  
Air Velocity ◽  
Globe Temperature ◽  
The University

This paper is focuses on the evaluation of the indoor climate in the small university lecture hall. Providing the optimal parameters of thermal comfort in the interiors of a university is immensely important for the students of the university. Fulfilling these parameters is inevitable not only for the physiological needs of students but also for the required performance of students. Reconstruction took place in the small university lecture hall. The original windows were exchanged for the modern wood tight windows. Experimental measurements were carried out in the winter season in 2016 in this small university lecture hall in order to evaluate the thermal comfort after the reconstruction. The device Testo 480 was used for the measurements. Obtained values of air temperature, air relative humidity, air velocity, globe temperature and indexes PMV, PPD are presented in the graphs. Heating, operation and architectural design of the small university lecture hall were evaluated on the basis of the parameters of thermal comfort. In the conclusion of this paper, there are principles how to design new small university lecture halls. Furthermore, there are presented recommendations how to operate the existing small university lecture halls.

scholarly journals Summer sleep quality and change of bedroom thermal environment – from the beginning to the end of sleep

2019 ◽  
Vol 111 ◽  
pp. 06054
Author(s):  
Noriko Umemiya ◽  
Kurumi Yamagata ◽  
Tomohiro Kobayashi
Keyword(s):  
Sleep Quality ◽  
Thermal Comfort ◽  
Thermal Environment ◽  
Subjective Sleep Quality ◽  
Wet Bulb Globe Temperature ◽  
Subjective Sleep ◽  
Environment Changes ◽  
Globe Temperature

Relations between bedroom thermal environment changes and subjective sleep quality and thermal comfort were surveyed for 63 apartment occupants during midsummer in Osaka. Changes of Wet Bulb Globe Temperature (WBGT) of 123 air-conditioned and 41 naturally ventilated nights were compared. 1) For air-conditioned bedrooms, sleep quality was better for smaller changes of WBGT from the beginning of sleep and for faster changes of WBGT to constant from the beginning of sleep. 2) For naturally ventilated bedrooms, a) WBGT increased from the beginning of sleep and decreased toward the end of sleep for higher sleep quality nights. However, WBGT decreased from the beginning of sleep and increased toward the end of sleep for lower sleep quality nights. b) The WBGT change was smaller for thermally comfortable nights.

A comparison of the thermal comfort performances of a radiation floor cooling system when combined with a range of ventilation systems

2019 ◽  
Vol 29 (4) ◽  
pp. 527-542 ◽  
Author(s):  
Jiying Liu ◽  
Zhuangzhuang Li ◽  
Moon Keun Kim ◽  
Shengwei Zhu ◽  
Linhua Zhang ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Cooling System ◽  
Whole Body ◽  
Equivalent Temperature ◽  
Thermal Discomfort ◽  
Computational Fluid Dynamics Simulations ◽  
Radiant Floor Cooling System ◽  
Personalized Ventilation ◽  
Dynamics Simulations ◽  
Ventilation Systems

This study conducted a series of computational fluid dynamics simulations to evaluate the thermal comfort performance of a radiant floor cooling system when combined with different ventilation systems, including mixed ventilation (MV), stratum ventilation (SV), displacement ventilation (DV) and ductless personalized ventilation (DPV). A window temperature of 32°C and three different floor temperatures including 20, 22 and 24°C were set in summer. We used the vertical air temperature differences (VATD) at ankle and head level, the percentage of dissatisfied, the draught rate at the ankle level and the equivalent temperature as our main evaluation indices. Our results show that the VATD in DV system can reach up to about 5°C, compared with about 2°C in MV and SV systems. For the DPV system, there is only a marginal drop in the VATD. For the DV and DPV cases, with a rate of air changes per hour (ACH) of 2.4−1, we recorded a higher draught rate at the ankle level, ranging from 6.55% to 9.99%. The lower equivalent temperature values for the foot and calf segments occur when the floor temperature is 20°C. In all cases, the equivalent temperature values of the whole body indicate an acceptable level of thermal discomfort.

scholarly journals Thermal Mitigation of the Indoor and Outdoor Climate by Green Curtains in Japanese Condominiums

Climate ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 8
Author(s):  
Hiroto Abe ◽  
Hom B. Rijal ◽  
Ryoga Hiroki ◽  
Kentaro Iijima ◽  
Akira Ohta
Keyword(s):  
Thermal Comfort ◽  
Green Infrastructure ◽  
Energy Use ◽  
Air Conditioner ◽  
Outdoor Climate ◽  
Globe Temperature ◽  
Thermal Mitigation ◽  
Mitigation Methods ◽  
Reducing Energy ◽  
Indoor And Outdoor

In recent years, “green curtains” have become one of the most prevalent thermal mitigation methods in Japan. They can be considered as green infrastructure for achieving thermal comfort and reducing energy use. To examine the thermal mitigation effect of the green curtain for practical applicability in the condominium, the indoor and balcony temperatures for 48 days both in households with and without green curtains were analyzed. The balcony globe temperature of the households with green curtains was 0.6 °C lower than that of the households without green curtains, during air-conditioner usage. Furthermore, the air-conditioner usage time of the households with green curtains was 40% less than that of the households without green curtains. The results showed that green curtains are effective for achieving both thermal mitigation and energy saving in a condominium.

scholarly journals Thermal comfort findings: Scenario at Malaysian automotive industry

2013 ◽  
Vol 17 (2) ◽  
pp. 387-396 ◽  
Author(s):  
Ahmad Ismail ◽  
Kumar Karagaratnan ◽  
Kumaran Kadirgama
Keyword(s):  
Thermal Comfort ◽  
Automotive Industry ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Human Subjects ◽  
Demographic Data ◽  
Working Environment ◽  
Paint Shop ◽  
Wet Bulb Globe Temperature ◽  
Globe Temperature

This paper discusses the findings of thermal comfort assessment at Malaysian automotive industry. Nine critical workstations were chosen as subjects for the study in order to determine the thermal comfort among workers at Malaysian automotive industry. The human subjects for the study comprises of the operators from tire receiving, dashboard assembly, drum tester, body assembly, seat assembly, door check assembly, stamping workstation, engine sub assembly and paint shop of the factory. The environmental factors such as Wet Bulb Globe Temperature (WBGT), relative humidity, air velocity, illuminance were measured using BABUC A apparatus and Thermal Comfort Measurement equipment. Through questionnaire survey, the demographic data of subjects and their perceptions on thermal comfort at each workstation were assessed based on ISO Standard 7730 and thermal sensation scale using Predicted Mean Vote (PMV). Then, Predicted Percentage of Dissatisfied (PPD) is used to estimate the thermal satisfaction of occupants. The results indicated that most of the workstations of the automotive industry are considered as uncomfortable. Tire receiving station is considered having better working environment compared to other stations with lowest PMV index of 1.09 to 1.41 and PPD of 46%. Meanwhile, the engine sub assembly station and paint shop of assembly are considered the worst thermal environment with the PMV index values ranging between 2.1 to 2.9 and PPD values of 81% to 99%. Therefore, these two workstations are considered not comfortable because the thermal sensation scale is warm and almost hot.

scholarly journals Energy Use and Perceived Indoor Environment in a Swedish Multifamily Building before and after Major Renovation

2018 ◽  
Vol 10 (3) ◽  
pp. 766 ◽  
Author(s):  
Lina La Fleur ◽  
Patrik Rohdin ◽  
Bahram Moshfegh
Keyword(s):  
Energy Efficiency ◽  
Thermal Comfort ◽  
Indoor Environment ◽  
Energy Use ◽  
Ventilation System ◽  
Heating Season ◽  
Indoor Temperature ◽  
Exhaust Ventilation ◽  
Heat Demand ◽  
Before And After

Improved energy efficiency in the building sector is a central goal in the European Union and renovation of buildings can significantly improve both energy efficiency and indoor environment. This paper studies the perception of indoor environment, modelled indoor climate and heat demand in a building before and after major renovation. The building was constructed in 1961 and renovated in 2014. Insulation of the façade and attic and new windows reduced average U-value from 0.54 to 0.29 W/m2·K. A supply and exhaust ventilation system with heat recovery replaced the old exhaust ventilation. Heat demand was reduced by 44% and maximum supplied heating power was reduced by 38.5%. An on-site questionnaire indicates that perceived thermal comfort improved after the renovation, and the predicted percentage dissatisfied is reduced from 23% to 14% during the heating season. Overall experience with indoor environment is improved. A sensitivity analysis indicates that there is a compromise between thermal comfort and energy use in relation to window solar heat gain, internal heat generation and indoor temperature set point. Higher heat gains, although reducing energy use, can cause problems with high indoor temperatures, and higher indoor temperature might increase thermal comfort during heating season but significantly increases energy use.

scholarly journals Thermal comfort models of venue in hot and humid subtropical regions

2021 ◽  
Vol 25 (6 Part A) ◽  
pp. 4225-4231
Author(s):  
Xiaodan Huang ◽  
Qingyuan Zhang ◽  
Xiaoli Ma
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Thermal Sensation ◽  
Evaluation Model ◽  
Least Square Method ◽  
Least Square ◽  
Predicted Mean Vote ◽  
Wet Bulb Globe Temperature ◽  
Globe Temperature ◽  
The Relationship

In order to improve the design effect of venues, this paper establishes the evaluation model of indoor thermal comfort for the humid and hot subtropical areas, which provides theoretical reference for venue design. This paper investigates the thermal sensation of basketball players by questionnaire, analyzes the relation-ship between thermal sensation vote and standard effective temperature, predicted mean vote, and wet bulb globe temperature, and develops an index called predicted thermal sensation by using the least square method. The relationship between outdoor air temperature and indoor working temperature under neutral conditions is obtained by measuring data. The results show that the correlation between thermal sensation vote and air temperature is the strongest, R2 is 0.753, while the relationship between thermal sensation vote and air speed is weak, R2 is 0.012. Thermal sensation vote and set, predicted mean vote and wet bulb globe temperature are not suitable for athletes in the field environment.

Analysis of Thermal Comfort in Flat in New High Residential Building

2016 ◽  
Vol 861 ◽  
pp. 361-368
Author(s):  
Mária Budiaková
Keyword(s):  
Thermal Comfort ◽  
Architectural Design ◽  
Residential Buildings ◽  
Winter Season ◽  
Residential Building ◽  
Heating System ◽  
Residential Areas ◽  
Air Velocity ◽  
Globe Temperature ◽  
The Individual

This paper focuses on the analysis of thermal comfort in a flat in the new high residential building. Providing the optimal parameters of thermal comfort in each room of the flat is the basic prerequisite for the satisfaction with housing. Incorrect position and size of heating elements, incorrect positioning of the furniture and incorrect use of residential interiors may significantly disturb the thermal comfort. Residential areas in the new residential buildings are much more intensively used as in the other types of buildings. Surface of new flats is the most optimized. Experimental measurements were carried out in the winter season in 2016 in the residential rooms of the large flat in the new high residential building. Device Testo 480 with temperature and humidity sensor, globe thermometer and turbulence sensor was used for the measurements. Obtained values of air temperature, air relative humidity, air velocity, globe temperature and indexes PMV, PPD are presented in the graphs. Heating system of the flat and the possibility of its regulation, positioning and size of the heating elements in the individual rooms, positioning of the furniture and the utilization of rooms were evaluated on the basis of parameters of thermal comfort. In the conclusion of the paper, there are principles on the architectural design of the residential interiors and their heating in the new residential buildings.

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