scholarly journals The Relation between Effective Temperature and Thermal Sensation Vote in Tropical Vernacular Houses

2020 ◽  
Vol 9 (3) ◽  
pp. 303-312
Keyword(s):  
Thermal Comfort ◽  
Effective Temperature ◽  
Air Conditioning ◽  
Thermal Sensation ◽  
Climate Variables ◽  
Measuring Instrument ◽  
Wet Season ◽  
Tropical Mountain ◽  
American Standard ◽  
Psychrometric Chart

One of the factors to enable energy efficiency in buildings is creating thermal comfort for the occupants of buildings so that the artificial vaporization is not required. The thermal sensation vote (TSV) is an indicator in analyzing the occupants’ satisfaction on the thermal comfort of their buildings. Some climate variables that relate to the TSV include air temperature, humidity, and wind speed. The three variables can be combined into a variable using a psychrometric chart. The combined variable is known as an effective temperature. The present research aims at analyzing the connection between effective temperature and TSV in vernacular houses in the tropical mountain and beach locations and comparing the results of the analysis. The quantitative method was employed in the research by measuring the variables of climate using a thermal measuring instrument. The TSV was measured with ASHRAE (American Standard of Heating, Refrigerating, Air-Conditioning Engineer)’s seven-point sensation scale. The measurement was carried out in transitional periods from the dry season to the wet season. Interpretation of graphs and charts was made for analysis based on the variable of effective temperature. The results of the research indicated that there was a connection between effective temperature and TSV. The effective temperature in vernacular houses in tropical mountain locations tended to be lower, and therefore the cool thermal sensation had the greatest percentage of TSV. Meanwhile, the effective temperature in tropical beach locations tended to be high, and therefore the warm thermal sensation had the greatest percentage. In a neutral scale, the percentage of TSV in tropical mountain locations was greater than that of TSV in tropical beach locations. Therefore, it is concluded that the occupants of vernacular houses in tropical mountain location felt more comfortable than those of vernacular houses in tropical beach locations.

scholarly journals Thermal Comfort Assessment at Parcel and Logistic Industry: A Field Study in Malaysia

2011 ◽  
Vol 72 (3) ◽  
Author(s):  
Ahmad Rasdan Ismail ◽  
Norfadzilah Jusoh ◽  
Mohd nizam ab. rahman Ab. rahman ◽  
Rozli Zulkifli ◽  
Kumaran Kardigama
Keyword(s):  
Thermal Comfort ◽  
Air Conditioning ◽  
Time Series Data ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Series Data ◽  
Energy Research ◽  
Iso Standard ◽  
Environment Factors ◽  
Solar Energy Research Institute

This paper presents the workers thermal sensation votes and perception of the thermal environment in air conditioning at one of the workspace in Malaysian parcel and logistic industry. The environment factors examined was the relative humidity (%), wind speed (m/s), air temperature (C) and CO2 (ppm) of the surrounding workstation area. These factors were measured using custom integrated thermal comfort apparatus namely as Thermal Comfort Equipment developed by Solar Energy Research Institute (SERI), Universiti Kebangsaan Malaysia, which is capable of measuring various environmental factors. The time series data of fluctuating level of environment factors were plotted to identify the significant changes and patterns among the factors. Then the thermal comfort of the workers was assessed by using ISO Standard 7730 and thermal sensation scale by using Predicted Mean Vote (PMV). Further Predicted Percentage Dissatisfied (PPD) is used to estimate the thermal comfort satisfaction of the occupant. Finally the PMV and PPD were plotted to present the thermal comfort scenario of workers involved in related workspace. The results revealed that the thermal comfort at the particular workplace was warming followed by thermal sensation and likely to be dissatisfied by dominant of occupants. The results also indicated that the CO2and index of clothing (clo) dominated the parameters of comfort to the occupants.

Investigation of the PMV and TSV Models of Thermal Comfort in Air-Conditioned University Classrooms in Malaysia

2016 ◽  
Vol 819 ◽  
pp. 207-211 ◽  
Author(s):  
Nur Atikah Shaari ◽  
Sheikh Ahmad Zaki ◽  
Mohamed Sukri Mat Ali ◽  
Azli Abd Razak
Keyword(s):  
Thermal Comfort ◽  
Field Study ◽  
Air Conditioning ◽  
Thermal Sensation ◽  
Humid Climate ◽  
Predicted Mean Vote ◽  
Hot And Humid Climate ◽  
University Classrooms ◽  
Adaptation Method

A field study was done on the thermal comfort of seven air-conditioned university classrooms in the hot and humid climate of Malaysia. The aims of this paper are to investigate the perceptions of thermal comfort and the adaptation method of students in air-conditioned classrooms. In total, 189 respondents from the classrooms completed the questionnaire. A comparison was made between the Predicted Mean Vote (PMV) and the Thermal Sensation Vote (TSV) and it was found that the TSV values tended to be more sensitive than the PMV values. A variety of adaptation methods of the occupants in the classrooms are also presented. It was found that most of the occupants preferred to change the air-conditioning thermostat, probably because all the occupants had the opportunity to control the thermostat.

Conserving Energy by Expanding the Thermal Comfort Envelope

1978 ◽  
Vol 22 (1) ◽  
pp. 533-536 ◽  
Author(s):  
Frederick H. Rohles
Keyword(s):  
Thermal Comfort ◽  
Indoor Air ◽  
Air Conditioning ◽  
Thermal Environment ◽  
Thermal Conditions ◽  
Heating And Cooling ◽  
American Society ◽  
Psychrometric Chart ◽  
Sedentary Activities

Standard 55–74 entitled “Thermal Conditions for Human Occupancy” which is published by The American Society of Heating, Refrigerating, and Air Conditioning Engineers, (ASHRAE) defines an “acceptable thermal environment” as one in which “at least 80 percent of the normally clothed men and women while engaged in indoor sedentary or near sedentary activities would express thermal comfort.” This is pictured on the ASHRAE psychrometric chart as an envelope that includes dry bulb temperatures between 74°F and 77°F at relative humidities between 20% and 60%. The paper will describe five human factors approaches that have been used or are being considered to expand this envelope and thereby conserve energy. These are (1) the use of small radiant heaters which are installed in the modesty panels of desks so comfort may be attained at lower temperatures; (2) the demonstration that night set-back of thermostats to temperatures as low as 50°F do not effect sleeping patterns; (3) the role that interior decor can play in making people feel warmer; (4) the effect that temperature “swings” associated with solar heating and cooling has upon acceptance of the thermal environment and (5) the acceptance of a reduced quality of indoor air as a result of heating with an increased ratio of recirculated air to outside air.

scholarly journals Determination of Thermal Comfort Zones through Comparative Analysis between Different Characterization Methods of Thermally Dissatisfied People

Buildings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 320
Author(s):  
Pedro Filipe da Conceição Pereira ◽  
Evandro Eduardo Broday
Keyword(s):  
Thermal Comfort ◽  
Air Conditioning ◽  
Energy Savings ◽  
Thermal Sensation ◽  
Probit Model ◽  
Energy Performance ◽  
Indoor Environmental Quality ◽  
Characterization Methods ◽  
American Society

In order to maintain thermal comfort and preserve indoor environmental quality, people use heating, ventilation and air-conditioning (HVAC) systems inside buildings. However, buildings must be prepared not only to provide adequate thermal comfort to their occupants but also to align strategies that enable better energy performance. Thus, this work aimed to establish thermal comfort zones (TCZ) through different characterization methods of thermally dissatisfied people. Responses were collected from 481 students, through the application of questionnaires in classrooms, during the Brazilian winter of 2019. Three methods for determining the actual percentage of dissatisfied (APD) were adopted, which generated three different equations, namely: APD_1; APD_2 and APD_3, based on the original Predicted Percentage of Dissatisfied (PPD) equation. By using the probit model, three TCZ were calculated: 17.73–22.4 °C (APD_1); 20.71–20.93 °C (APD_2) and 17.89–24.83 °C (APD_3). In addition, a comfort zone based on the linear regression between the thermal sensation votes and the operative temperature was determined (18.77–22.69 °C). All thermal comfort zones resulting from this work have colder temperatures than that indicated by the American Society of Heating, Refrigerating and Air-Conditioning Engineers - ASHRAE (2017) of 23–26 °C for the winter, showing the potential for energy savings from the adoption of this type of strategy, while maintaining thermal comfort.

scholarly journals Sensasi Termal Pelajar di Dalam Ruang Kelas

NALARs ◽  
2020 ◽  
Vol 19 (2) ◽  
pp. 81
Author(s):  
Humairoh Razak ◽  
Fitri Wulandari
Keyword(s):  
Climate Change ◽  
Thermal Comfort ◽  
Effective Temperature ◽  
School Environment ◽  
Air Conditioning ◽  
Qualitative Method ◽  
Thermal Conditions ◽  
Primary Sources ◽  
Global Emission ◽  
Quantitative And Qualitative Methods

ABSTRAK. Kota Banjarmasin memiliki iklim tropis lembab, kenyamanan termal menjadi unsur kenyamanan yang vital untuk dicapai khususnya untuk efektifitas kegiatan belajar bagi pelajar. Terutama dengan terjadinya pemanasan global, penggunaan penghawaan buatan seperti Air Conditioning (AC) justru akan memperparah terjadinya climate change karena AC merupakan salah satu sumber utama penghasil emisi. Metode pelaksaan penelitian ini dengan menggabungkan metode kuantitatif dan kualitatif. Metode kuantitatif digunakan untuk mengetahui kondisi termal di dalam dan di luar ruang kelas dengan mencari temperatur efektif kondisi termal di dalam ruang kelas dan kondisi iklim lingkungan sekolah dengan menggunakan alat environmental meter. Sedangkan metode kualitatif untuk mengetahui sensasi termal yang dirasakan pelajar saat berada di dalam ruang kelas, pengambilan data dilakukan 3 kali dengan interval 2 jam dimulai pukul 08.00 WITA. Hasil penelitian menunjukan bahwa sensasi termal yang dirasakan oleh pelajar pada pukul 08.00 dan pukul 10.00 WITA kurang dari 30% yang merasa nyaman saat berada di dalam ruang kelas dan tersisa hanya 5.14% pelajar yang merasa nyaman pada pukul 12.00 WITA. Puncaknya pada pukul 12.00 WITA saat matahari berada persis di puncak tertinggi 93.15% pelajar merasakan kepanasan, yaitu terasa agak panas, panas dan panas sekali. Hal ini didukung dengan data kuantitatif yang temperatur efektif di dalam ruang kelas berada di atas batas kenyamanan Webb, yaitu 30.58°C TE pada pukul 08.00 WITA, meningkat menjadi 31.38°C TE pada pukul 10.00 WITA dan puncak tertinggi pada pukul 12.00 WITA mencapai 31.57°C TE. Kata kunci: Kenyamanan Termal, Temperatur Efektif, Lubang Udara, Ruang Kelas, Ventilasi Silang ABSTRACT. Banjarmasin city has a humid tropical climate, which makes thermal comfort one of the vital comfort elements to be achieved. Especially for the effectiveness of the students' learning activities. Global warming is a hot topic today; the use of artificial ventilation such as air conditioning (AC) will aggravate climate change. AC is one of the primary sources of global emission. This research used both quantitative and qualitative methods. The quantitative approach is used to determine thermal conditions inside and outside the classroom by finding the classroom's effective temperature and school environment using environmental meter tools. On the other hand, the qualitative method is used to determine student's thermal sensations inside the classroom. Data collection was carried out three times in 2-hour intervals starting at 08.00 WITA. The results showed that the students' thermal feeling inside the classroom at 8:00, and 10:00 WITA was less than 30% who felt comfortable while only 5.14% felt comfortable at 12.00 WITA. The peak is at 12.00 WITA when the sun is precisely at the highest peak, 93.15 % of students feel discomfort, which is feeling rather hot, hot, and very hot. This is supported by quantitative data where the effective temperature in the classroom is over Webb's comfort limit, which is 30.58 ° C ET at 08.00 WITA, increasing to 31.38 ° C at 10:00 WITA and the highest peak at 12.00 WITA reaching 31.57 ° C ET. Keywords: Thermal Comfort, Effective Temperature, Air Opening, Classroom, Cross Ventilation

The Modal Comfort Envelope and its Use in Current Standards

1974 ◽  
Vol 16 (3) ◽  
pp. 314-322 ◽  
Author(s):  
Frederick H. Rohles
Keyword(s):  
Thermal Comfort ◽  
Effective Temperature ◽  
Temperature Scale ◽  
Thermal Sensation ◽  
The Elderly ◽  
Current Standards

A detailed study of thermal comfort was conducted by exposing 1600 subjects, in groups of 10 subjects each (5 men and 5 women), to 20 dry bulb temperatures at each of eight relative humidities (160 tests). From this study, 15 temperature-humidity conditions were selected (ET: 75.9-79.7°F) and identified as the Modal Comfort Envelope (MCE). Within this envelope 94% of the subjects were either slightly cool, comfortable, or slightly warm; 3% were cool and 3% were warm; and none were hot or cold. To validate these findings, a new sample of 150 subjects was tested and the results of this test agree favorably with the original findings. The MCE was used in a clothing study and in an investigation of thermal comfort in the elderly; the results of these studies are discussed, together with suggestions for the use of the Modal Comfort Envelope, as a tool for examining the thermal sensation as a function of such non-thermal factors as lighting, subject density, sex, and activity. A slightly modified version of the MCE is currently being used as a standard for thermal comfort by ASHRAE and this is examined together with ASHRAE Comfort Standard 55–66, the New ASHRAE Comfort Chart, and the new Effective Temperature Scale.

scholarly journals Experimental Study and Analysis of Thermal Comfort in a University Campus Building in Tropical Climate

2020 ◽  
Vol 12 (21) ◽  
pp. 8886
Author(s):  
Milen Balbis-Morejón ◽  
Javier M. Rey-Hernández ◽  
Carlos Amaris-Castilla ◽  
Eloy Velasco-Gómez ◽  
Julio F. San José-Alonso ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Air Conditioning ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Thermal Sensitivity ◽  
Tropical Climate ◽  
Air Conditioning System ◽  
Humidity Measurements ◽  
Air Conditioning Systems ◽  
Thermal Preferences

This study presents the evaluation of the performance and acceptability of thermal comfort by students in the classrooms of a university building with minisplit-type air-conditioning systems, in a tropical climate. To carry out the study, temperature and humidity measurements were recorded, both outside and inside the selected classrooms, while the students were asked to complete thermal surveys on site. The survey model is based on the template proposed by Fanger and it was applied to a total number of 584 students. In each classroom, the Predicted Mean Vote (PMV) and the Predicted Percentage Dissatisfied (PPD) were estimated according to Fanger’s methodology, as well as the Thermal Sensation Vote (TSV) and the Actual Percentage Dissatisfied (APD), which were obtained from the measurements and the surveys. The results of this study showed that the PMV values, although they may vary with the insulation of the clothing, do not affect the TSV. Furthermore, comparing PMV vs. TSV scores, a 2 °C to 3 °C difference in operating temperature was found, whereby the thermal sensitivity for TSV was colder, so it could be assumed that the PMV model overestimates the thermal sensitivity of students in low-temperature conditions. In addition, an acceptability by 90% with thermal preferences between 23 °C and 24 °C were also found. These results indicate that it is possible to increase the temperature set point in minisplit-type air-conditioning system from 4 °C to 7 °C with respect to the currently set temperatures, without affecting the acceptability of the thermal environment to the students in the building.

Evaluation of Human Thermal Comfort Using Near-Infrared Spectroscopy

2014 ◽  
Author(s):  
Keiichi Watanuki ◽  
Lei Hou ◽  
Yuuki Kondou
Keyword(s):  
Energy Consumption ◽  
Thermal Comfort ◽  
Air Conditioning ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Brain Activation ◽  
Indoor Temperature ◽  
Prefrontal Area ◽  
Human Thermal Comfort ◽  
Conditioning Control

Air-conditioning equipment is used in various places such as houses, office buildings, and public facilities and is indispensable in modern-day life. Therefore, the energy consumption of air-conditioning equipment accounts for a large percentage of the total energy consumption in the average household. Specifically, it accounts for 26% of the annual energy consumption in ordinary homes and 27% in industry, according to the Annual Energy Report for Japan, which was presented by the Ministry of the Economy, Trade, and Industry, and the Agency for Natural Resources and Energy in 2010. Therefore, it is desirable to reduce energy consumption by reducing the air-conditioning load. The Ministry of the Environment recommends a constant preset temperature of 28°C in summer to decrease energy consumption. However, many people feel uncomfortable in such a thermal environment. Thus, an air-conditioning control to simultaneously suppress energy consumption and maintain human thermal comfort is desired. To develop such a control, an index to accurately evaluate human thermal comfort is needed. When a person feels comfortable or uncomfortable, their prefrontal area, which is involved in thinking and the feeling of emotions, is activated. It is presumed that the measurement of the brain activation reaction of a person will reveal whether the person feels comfortable or uncomfortable in the thermal environment. The evaluation of thermal comfort by means of brain activation reactions will allow one to develop the optimum air-conditioning control to maintain human thermal comfort. This paper proposes a method to evaluate thermal comfort via brain signals and ultimately aims to develop an air-conditioning control system utilizing this evaluation method. This paper will describe the measurement procedure of brain activation reactions to indoor-temperature change by using near-infrared spectroscopy and the relationship between thermal comfort and brain activation reaction. This study also investigated the changes in oxyHb levels together with indoor-temperature changes, measured with the NIRS. We measured the changes in the oxyHb levels of the prefrontal area when the temperature increased and decreased. As a result, the oxyHb level in the prefrontal area correlated with the indoor-temperature change, the PMV, and the subjects’ declaration of thermal sensation. Conversely, the change in the oxyHb level with the inclusion of wind and a constant indoor temperature significantly differed with that with a varying indoor temperature. Furthermore, the oxyHb change correlated with the PMV and the subject’s declaration of thermal sensation. Therefore, the measured oxyHb change may represent the thermal comfort of a person.

scholarly journals AN ANALYSIS IN THE IMPLICATION OF THERMAL ENERGY DISTRIBUTION TOWARDS HUMAN COMFORT IN AN OFFICE SPACE

2015 ◽  
Vol 3 (1) ◽  
pp. 15-30
Author(s):  
Ahmad Rasdan Ismail ◽  
Norfadzilah Jusoh ◽  
Rosli Abu Bakar ◽  
Nor Kamilah Makhtar ◽  
Suriatini Ismail
Keyword(s):  
Energy Distribution ◽  
Thermal Comfort ◽  
Thermal Energy ◽  
Air Conditioning ◽  
Thermal Sensation ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Temperature Level ◽  
Indoor Space ◽  
Different Levels

AbstrakKajian ini bertujuan untuk menyiasat pengedaran tenaga haba terhadap prestasi seorang pekerja disebuah bangunan pejabat. Hawa dingin adalah penting untuk mengekalkan keselesaan terma persekitarandalam ruang tertutup, terutama untuk iklim di Malaysia. Untuk menyiasat sensasi berkesan haba daripadamereka yang bekerja dalam persekitaran yang tidak seragam, adalah amat penting untuk menentukanbutir-butir pemindahan haba tempatan. Dalam konteks ini, tujuan kajian ini adalah untuk membandingkanantara haba keselesaan dan suhu tetapan penyaman udara. Suhu dikekalkan pada lima tahap yangberbeza iaitu 19, 21, 23, 26 dan 29oC. Kajian ini telah dijalankan di dalam ruang alam sekitar di UniversitiMalaysia Pahang. Hasil kajian menunjukkan bahawa suhu antara 21-29oC dan kelembapan relatif antara50-60% boleh memberi perubahan kepada tahap suhu kulit yang menunjukkan tahap keselesaan yangdialami oleh subjek.   AbstractThis study aims to investigate thermal energy distribution on a worker’s performance in an officebuilding. Air conditioning is essential for maintaining environment thermal comfort in indoor space,especially for the climate in Malaysia. In order to investigate an effectual thermal sensation of thoseworking in a non-uniform environment, it is very important to define the local heat transfer details. Inthis context, the purpose of this study is to compare between thermal comfort and temperature settingsof air conditioning. The temperature was maintained at five different levels which are 19, 21, 23, 26and 29oC. The study was carried out in the environmental chamber at University Malaysia Pahang.The result shows that the temperature settings between 21-29oC and relative humidity between 50-60% can give a difference to skin temperature level that indicates the level of comfort experienced bythe subjects.

Enhancing Thermal Comfort with Ceiling Fans

1982 ◽  
Vol 26 (2) ◽  
pp. 118-120 ◽  
Author(s):  
Frederick H. Rohles ◽  
Stephan A. Konz ◽  
Byron W. Jones
Keyword(s):  
Thermal Comfort ◽  
Energy Demand ◽  
Air Conditioning ◽  
Energy Savings ◽  
Rating Scale ◽  
Thermal Sensation ◽  
National Bureau ◽  
Category Rating ◽  
Temperature Preference ◽  
Subjective Responses

To determine the effectiveness of ceiling fans in enhancing comfort, 256 subjects were examined at 24.4 C (76 F), 26.1 C (79 F), 27.8 C (82 F), and 29.4 C (85 F) (all at 50% rh), in an environmental chamber that was equipped with a ceiling fan that produced four velocity conditions: 0.15 m/s (30 fpm), 0.25 m/s (50 fpm), 0.46 m/s (90 fpm), and 1.02 m/s (200 fpm). A fifth velocity, in which the fan was not employed, was 0.06 m/s (10 fpm); this served as the control velocity. Three subjective responses were measured: thermal sensation (a 9-category rating scale), thermal comfort (a 7-pair semantic differential scale), and a question on temperature preference. The results showed that an air plume from a ceiling fan whose velocity is between 0.5 and 1.0 m/s (90 and 200 fpm) compensates for a 2.8–3.3°C (5–6°F) temperature change; this represents an energy savings of 15–18% when based on the National Bureau of Standards' suggestion of a reduction in air conditioning energy demand of 6% per °C or 3% per °F. It also concluded that a ceiling fan may extend the upper limit of the summer comfort envelope from 26.1 to 29.4 C (79 to 85 F) and that the turbulent and variable characteristics of the air plume of the ceiling fan may be its major comfort-producing attribute.

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