On the Development of a Thermal Comfort Control for Classrooms Conditioned by Split-Type Systems

2019 ◽  
Author(s):  
Anastacio Silva Junior ◽  
Nathan Mendes ◽  
Rogério Vilain ◽  
Marcelo Pereira ◽  
Katia Cordeiro Mendonça
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Low Cost ◽  
Type System ◽  
Type Systems ◽  
General Purpose ◽  
Representative Point ◽  
Air Velocity ◽  
Comfort Index ◽  
Air Speed

Abstract Thermal comfort conditions may vary substantially within an air-conditioned room equipped by split-type systems. In this work, the comfort conditions in a classroom were evaluated experimentally based on the PMV index, according to ISO 7730 Standard that defines the thermal satisfaction in occupied environments. The experiment was carried out at three different supply airflows (high, medium and low) and three set-point temperatures (23, 24 and 25°C). The results showed that there is a considerable variation in the air velocity field in the room as well as in the PMV values for three different supply airflows, consequently significant changes of thermal comfort indices can be noticed. Several curves were adjusted aiming to express the values of PMV, deriving a simplified comfort index for rooms conditioned by split-type systems based on dry-bulb air temperature and air speed. The purpose of this adjustment is to obtain an equation that provides the value of the comfort index for cooling purposes. Thus, for a certain condition of use, one can predict what will be the value of PMV in an occupied environment, enabling the implementation of a control system of the comfort according to this new index (ICS). The variables considered in obtaining the curve were the air temperature (Tar) and the air velocity (Var), since these two variables can be controlled directly by the split-type system. The general purpose of this work is to provide experimental data for the development of a low-cost device to automatically control ICS-based thermal comfort in a space conditioned by a split-type system through a single and representative point within the classroom.

scholarly journals PENGARUH BUKAAN SAMPING (CLERESTORY) TERHADAP KUALITAS KENYAMANAN TERMAL PADA FOOD CARNIVAL, MALL AEON BSD

Vitruvian ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 47
Author(s):  
Tathia Edra Swasti
Keyword(s):  
Wind Speed ◽  
Thermal Comfort ◽  
Air Temperature ◽  
Effective Temperature ◽  
Air Humidity ◽  
Air Velocity ◽  
Predicted Mean Vote ◽  
Air Speed ◽  
The Right

ABSTRAK Mall saat ini marak menggunakan clerestory sebagai salah satu upaya untuk penerangan alami pada siang hari. Namun, cahaya matahari pada sore hari (barat) akan menghasilkan cahaya matahari yang lebih panas dan silau dibandingkan cahaya matahari pada pagi hari (timur). Oleh karena itu, dengan pemakaian clerestory yang cukup besar pada bangunan, masalah panas tentu tak dapat dihindari. Begitu pula dengan glare yang berasal dari pantulan sinar matahari. Salah satu Mall yang menggunakan clerestory adalah Mall AEON BSD. Pengukuran suhu udara, temperatur efektif, kelembaban udara, kecepatan angin, PMV (Predicted Mean Vote) dan PPD (Predicted Percentage of Dissatisfied) dilaksanakan pada 4 waktu dengan 5 lokasi titik ukur yang memiliki kondisi berbeda untuk membuktikan bahwa clerestory dapat mempengaruhi kenyamanan termal. Disimpulkan bahwa titik 2 yaitu titik yang berdekatan dengan clerestory sisi kanan (ukurannya lebih kecil daripada clerestory sisi kiri) memiliki temperatur efektif dan kelembaban udara yang lebih rendah dari titik lain, dan kecepatan udara (dipengaruhi oleh hembusan AC) lebih tinggi dari titik lain. Responden merasa nyaman saat berada di titik tersebut.Titik paling nyaman menurut responden adalah titik 2 dengan TE rata-rata berkisar 27,4˚C, kelembaban udara rata-rata berkisar 52,2%, kecepatan udara rata-rata berkisar 0,15 m/s, PMV berkisar 0,5 dan PPD berkisar 12,7%. Dengan begitu semakin kecil ukuran skylight terbukti mempengaruhi kenyamanan termal dan membuat kenyamanan termal dapat tercapai. Kata Kunci: Mall, Clerestory, PMV, PPD, Kenyamanan Termal ABSTRACT Nowadays mall is decorated with clerestory as an effort to lighten naturally during the day. However, sunlight in the afternoon (west) will produce more sunlight and glare than sunlight in the morning (east). Therefore, with the use of a fairly large clerestory in buildings, the problem of heat certainly can not be avoided. Similarly, glare that comes from the reflection of sunlight. One of the malls that use clerestory is BSD AEON Mall. Measurement of air temperature, effective temperature, air humidity, wind speed, PMV (Predicted Mean Vote) and PPD (Predicted Percentage of Dissatisfied) carried out at 4 times within 5 measuring spots that have different conditions, proving that clerestory can affect thermal comfort. It was concluded that point 2, which is the point adjacent to the right side clerestory (smaller in size than the left side clerestory) has an effective temperature and lower air humidity than other points, and air velocity (affected by blowing AC) is higher than other points. Respondents felt comfortable when they were at that point. The most comfortable point according to respondents was point 2 with TE averaging around 27.4˚C, air humidity averaged 52.2%, the average air speed ranged from 0.15 m / s, PMV ranges from 0.5 and PPD ranges from 12.7%. Thus, the smaller size of the clerestory is affecting thermal comfort and thermal comfort can be achieved. Keywords: Mall, Clerestory, PMV, PPD, Thermal Comfort

CFD-Based Parametric Analysis on the Performance of Personalized Partition Air Distribution Systems

Solar Energy ◽  
2006 ◽  
Author(s):  
Kybum Jeong ◽  
Moncef Krarti ◽  
Zhiqiang Zhai
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Distribution System ◽  
Distribution Systems ◽  
Comfort Level ◽  
Cfd Modeling ◽  
Air Distribution ◽  
Air Velocity ◽  
Comfort Index ◽  
System Mode

The partition air distribution systems evaluated in this study allow occupants to control the system mode (on/off) and the supply air velocity and direction with similar flexibility as occupants in automobiles. To find optimal specifications for the partition air distribution systems that are able to achieve comfortable micro-environment, a CFD modeling tool was used to simulate the airflow and thermal performance of the partition air distribution systems in a typical office space. By analyzing the distribution characteristics of indoor air temperature, air velocity and thermal comfort index, the study assessed the performance of the partition air distribution systems with different operating parameters. The simulation results were analyzed and evaluated to assess both occupant’s thermal comfort and system energy consumption. The study shows that space cooling energy can be reduced while maintaining acceptable indoor thermal comfort level using a partition air distribution system with a higher supply air temperature.

scholarly journals Thermal comfort and draught assessment in a modern open office building in Tallinn

2019 ◽  
Vol 111 ◽  
pp. 02013 ◽  
Author(s):  
Martin Kiil ◽  
Alo Mikola ◽  
Martin Thalfeldt ◽  
Jarek Kurnitski
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Energy Demand ◽  
Working Environment ◽  
Office Building ◽  
Indoor Climate ◽  
Air Velocity ◽  
Air Exchange Rate ◽  
Air Speed ◽  
Open Office

Modern office building users have high expectations about the working environment and thermal comfort, which requires the installation of complex technical systems such as combined cooling and ventilation. Room conditioning units of these systems must ensure temperature and ventilation control in a way that air velocity is low and the air temperature in acceptable range. Achieving air distribution avoiding draught is one of the key elements of a thermal comfort in modern office landscape. Higher air velocity in occupied zone is easily perceived as draught, which causes occupant dissatisfaction and complaints, as well as decrease in the productivity or effective floor space area. To reduce complaints, room air temperature setpoints or ventilation airflow rates are often modified, which may result in higher heating energy demand. In addition, excessive heating setpoint rise will not only consume more energy, but may cause health problems. Compared to cellular offices it is more difficult to ensure thermal comfort conditions in open office spaces where there are no walls for air flows. In addition, due to the higher number of employees it is more difficult to meet satisfactory conditions for everyone. The aim of this study was to evaluate thermal comfort parameters such as room air temperature, air speed and supply air temperature and how the users sense it in a modern office building in Tallinn, Estonia. Design room air temperature setpoints and air exchange rate were evaluated on open office spaces. Measured data with web-based indoor climate questionnaire was analysed. Results show which design and measured parameters make it possible to match the user comfort at all times.

scholarly journals On the improvement of thermal comfort in indoor spaces conditioned by split-type systems

2019 ◽  
Vol 111 ◽  
pp. 02052
Author(s):  
Silva Júnior Anastácio da ◽  
Cordeiro Mendonça Kátia ◽  
Vilain Rogério ◽  
Pereira Marcelo Luiz ◽  
Mendes Nathan
Keyword(s):  
Thermal Comfort ◽  
Low Cost ◽  
Type System ◽  
Type Systems ◽  
Cooling Capacity ◽  
Linear Regression Method ◽  
Airflow Rate ◽  
Set Point ◽  
Air Supply ◽  
Radiant Temperature

Conventional on/off-based control split-type appliances are widely used in classrooms and offices, in Brazil and in many other countries, due to their low cost and ease of installation. However, occupants often complain about thermal discomfort depending on their position within the conditioned space, especially in positions that are directly affected by the draft, since those equipment provide high cold air velocities as a result of their high cooling capacity relatively to their air supply area. In order to improve the indoor thermal comfort in spaces conditioned by this kind of system, a simplified empirical model for controlling both the supply airflow and the temperature set-point is proposed in this work. In view of that, the comfort conditions in an occupied classroom were experimentally evaluated according to ISO 7730 Standard, which defines the thermal satisfaction in occupied environments based on the PMV index. Specifically, the speed, temperature and relative humidity of the air and the mean radiant temperature of the room were measured at 8 positions within the air conditioned space, for the three original air flows (high, medium and low) of a 10.5-kW cooling capacity appliance and three set-point temperatures (23, 24 and 25 °C). The simplified model, correlating thermal comfort and the variables that could be directly controlled by the split-type system (airflow rate and temperature), was obtained by adjusting several curves from 72 measuring assemblies (8 measuring points, 3 set-point temperatures and 3 supply airflows). The correlation that best represents the distribution of thermal comfort throughout the conditioned environment was provided by the non-linear regression method of Levenberg-Marquardt.

scholarly journals THERMAL COMFORT INVESTIGATION ON HOLY MOSQUE IN BANDUNG Case Study : Lautze 2 Mosque Bandung

2020 ◽  
Vol 2 (1) ◽  
pp. 82
Author(s):  
Agung Prabowo
Keyword(s):  
Thermal Comfort ◽  
Quantitative Research ◽  
Thermal Environment ◽  
Tropical Climate ◽  
Air Humidity ◽  
Air Velocity ◽  
Related Factors ◽  
Climate Conditions ◽  
Comfort Index ◽  
Main Factors

Abstract -Thermal comfort is a state of mind that expresses satisfaction with the thermal environment. There are two main categories in the effort to obtain a comfort index; empirical and analytical. Empirical is based on social surveys, while analysis is based on the physics principle of heat flow.Bandung city is one of the historical cities in Indonesia which has many historical heritage buidings. One of them which is commonly known as colonial buildings in Bandung is Lautze 2 Mosque, located at Tamblong Street in the city center of Bandung. This research was conducted to analyze the thermal comfort in the Lautze 2 Mosque Bandung. The analytical method used in this study is a quantitative research method by measuring the main factors namely air temperature, air humidity and air velocity. The main factors become obstacles to get thermal comfort data at the Lautze 2 Mosque Bandung is the location of buildings located in areas with tropical climate conditions with high air temperatures, high air humidity, and low air velocitys.The research conclude that thermal comfort in the Lautze 2 Mosque Bandung building can be categorized as uncomfortable, it can be seen from the measurement results of related factors, namely the temperature and humidity that exceeds the comfort limit and the low air velocity in the building becomes an obstacle to obtain thermal comfort. Keywords: colonial buildings, mosque, thermal comfort, tropical climate.

scholarly journals Thermal comfort of patients in hospital ward areas

1977 ◽  
Vol 78 (1) ◽  
pp. 17-26 ◽  
Author(s):  
R. M. Smith ◽  
A. Rae
Keyword(s):  
Steady State ◽  
Thermal Comfort ◽  
Air Temperature ◽  
Hospital Ward ◽  
Patient Comfort ◽  
Mean Radiant Temperature ◽  
Air Velocity ◽  
Assessment Techniques ◽  
The Mean ◽  
Radiant Temperature

SUMMARYThe patient is identified as being of prime importance for comfort standards in hospital ward areas, other ward users being expected to adjust their dress to suit the conditions necessary for patient comfort. A study to identify the optimum steady state conditions for patient comfort is then described.Although this study raises some doubts as to the applicability of the standard thermal comfort assessment techniques to ward areas, it is felt that its results give a good indication of the steady-state conditions preferred by the patients. These were an air temperature of between 21.5° and 22° C and a relative humidity of between 30% and 70%, where the air velocity was less than 0.1 m/s and the mean radiant temperature was close to air temperature.

A Data-Driven Thermal Sensation Model Based Predictive Controller for Indoor Thermal Comfort and Energy Optimization

2014 ◽  
Author(s):  
Xiao Chen ◽  
Qian Wang
Keyword(s):  
Thermal Comfort ◽  
Thermal Sensation ◽  
Energy Optimization ◽  
Data Driven ◽  
Air Velocity ◽  
Comfort Index ◽  
Indoor Thermal Comfort ◽  
Occupant Feedback ◽  
Predictive Controller ◽  
Radiant Temperature

This paper proposes a model predictive controller (MPC) using a data-driven thermal sensation model for indoor thermal comfort and energy optimization. The uniqueness of this empirical thermal sensation model lies in that it uses feedback from occupants (occupant actual votes) to improve the accuracy of model prediction. We evaluated the performance of our controller by comparing it with other MPC controllers developed using the Predicted Mean Vote (PMV) model as thermal comfort index. The simulation results demonstrate that in general our controller achieves a comparable level of energy consumption and comfort while eases the computation demand posed by using the PMV model in the MPC formulation. It is also worth pointing out that since we assume that our controller receives occupant feedback (votes) on thermal comfort, we do not need to monitor the parameters such as relative humidity, air velocity, mean radiant temperature and occupant clothing level changes which are necessary in the computation of PMV index. Furthermore simulations show that in cases where occupants’ actual sensation votes might deviate from the PMV predictions (i.e., a bias associated with PMV), our controller has the potential to outperform the PMV based MPC controller by providing a better indoor thermal comfort.

scholarly journals Featherweight generic confinement

2006 ◽  
Vol 16 (6) ◽  
pp. 793-811 ◽  
Author(s):  
ALEX POTANIN ◽  
JAMES NOBLE ◽  
DAVE CLARKE ◽  
ROBERT BIDDLE
Keyword(s):  
Programming Languages ◽  
Ad Hoc ◽  
Type System ◽  
Type Systems ◽  
General Purpose ◽  
Ownership Type ◽  
Essential Change ◽  
Polymorphic Type ◽  
Syntactic Restrictions

Existing approaches to object encapsulation either rely on ad hoc syntactic restrictions or require the use of specialised type systems. Syntactic restrictions are difficult to scale and to prove correct, while specialised type systems require extensive changes to programming languages. We demonstrate that confinement can be enforced cheaply in Featherweight Generic Java, with no essential change to the underlying language or type system. This result demonstrates that polymorphic type parameters can simultaneously act as ownership parameters and should facilitate the adoption of confinement and ownership type systems in general-purpose programming languages.

Analysis of Natural Ventilation Systems in Schoolrooms

2016 ◽  
Vol 824 ◽  
pp. 625-632
Author(s):  
Mária Budiaková
Keyword(s):  
Mechanical Ventilation ◽  
Thermal Comfort ◽  
Energy Saving ◽  
Air Temperature ◽  
Natural Ventilation ◽  
Winter Period ◽  
Experimental Measurements ◽  
Air Velocity ◽  
The Future ◽  
Ventilation Systems

The paper is oriented on the analysis of the ventilation systems in schoolrooms. Correct and sufficient ventilation of schoolrooms is very important because students and pupils spend in the schoolrooms the majority of their time in school. In our schools the ventilation is incorrect and insufficient. The biggest problem is winter period when the ventilation is provided only by opening the doors to corridor. This way, there is insufficient intake of oxygen, which causes distractibility and feeling of tiredness of pupils. In current schoolrooms we can use only natural ventilation and thus the schoolrooms have to be ventilated using windows. Therefore this research was focused on the comparison and the analysis of different systems of natural ventilation in schoolrooms. The experimental measurements were carried out in schoolroom, where the parameters of thermal comfort were measured in the different systems of natural ventilation with device Testo 480 which was connected to computer. Gained values of air temperature, air velocity and index PMV are presented in graphs. On the base of analysis of measured values were evaluated the systems of natural ventilation for schoolrooms. In the future, the mechanical ventilation in schoolrooms can be assumed, therefore the recommendation on modern energy saving system of mechanical ventilation is in the end of this paper.

scholarly journals UMA INTRODUÇÃO AO CONFORTO TERMO-AMBIENTAL DO COLÉGIO ESTADUAL SANTA GEMMA GALGANI, CURITIBA, PARANÁ, BRASIL

FLORESTA ◽  
2014 ◽  
Vol 45 (2) ◽  
pp. 409 ◽  
Author(s):  
Daniela Biondi ◽  
Angeline Martini ◽  
Everaldo Marques de Lima Neto
Keyword(s):  
Relative Humidity ◽  
Thermal Comfort ◽  
Air Temperature ◽  
Comfort Index ◽  
State College ◽  
Outdoor Area ◽  
Different Seasons ◽  
Pet Index ◽  
Outer Area ◽  
Made In

O objetivo desta pesquisa foi avaliar as condições de conforto térmico do Colégio Estadual Santa Gemma Galgani, Curitiba, PR comparando ambientes internos e externos em diferentes estações do ano. A análise do conforto térmico foi realizada através do índice PET. As coletas foram feitas no outono, inverno e primavera de 2011, em dois dias e em dois ambientes distintos. Em cada dia de coleta, foi instalado um equipamento dentro da sala de aula e outro na área externa (pátio), caracterizada como: ambiente 1 - área externa com mais de 90% de impermeabilização e menos árvores; e ambiente 2 - área externa com menos de 30% de impermeabilização e mais árvores. A área do colégio possui 7.634,91 m2, sendo 36,56% de áreas permeáveis e 60,44% de impermeáveis. Nas três estações do ano, a temperatura do ar foi mais alta no pátio, com exceção do outono para o ambiente 1 e da primavera para o ambiente 2. Houve diferenças significativas nas condições de conforto entre os ambientes 1 e 2, indicando que as áreas são distintas pela permeabilidade e quantidade de vegetação. Conclui-se que, no geral, as salas de aula do colégio nas estações do outono, inverno e primavera apresentaram conforto térmico na maioria do período observado.Palavras-chave: Índice PET; Termômetro de Globo; temperatura do ar; umidade relativa do ar. AbstractAn introduction to thermal-environmental comfort state college St. Gemma Galgani, Curitiba, Parana, Brazil. The aim of this study was to evaluate the thermal comfort of the State College Santa Gemma Galgani, Curitiba, PR comparing internal and external environments in different seasons. The analysis of thermal comfort index was performed using PET. Collections were made in the fall, winter and spring of 2011 in two days and in two different environments. Every day a collect was installed equipment within the classroom and another in the outer area (outdoor), characterized as an environment 1 - outdoor area with more than 90% of waterproofing and fewer trees; and the environment 2 - external area under 30% waterproofing and more trees. The area of the college has 7634.91 m2 and 36.56% to 60.44% permeable areas and waterproof. In three seasons, the air temperature was higher in the courtyard, with the exception of autumn to the environment and a spring for the environment 2. There were significant differences in terms of comfort between locations 1 and 2, indicating that the areas are distinct permeability and the amount of vegetation. It is concluded that, overall, the classrooms of the college stations in the fall, winter and spring had thermal comfort for most of the observed period.Keywords: PET index; Globe Thermometer; air temperature; relative humidity.

Sign in / Sign up

Export Citation Format

Share Document