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 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

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 Selected Aspects of Indoor Climate in a Passive Office Building with a Thermally Activated Building System: A Case Study from Poland

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 860
Author(s):  
Piotr Michalak
Keyword(s):  
Air Temperature ◽  
Thermal Conditions ◽  
Office Building ◽  
Normal Operation ◽  
Indoor Climate ◽  
Thermally Activated ◽  
System A ◽  
Warm Sensation ◽  
Building System ◽  
Heating Energy Consumption

Modern buildings with new heating, ventilation and air conditioning (HVAC) systems offer possibility to fit parameters of the indoor environment to the occupants’ requirements. The present paper describes the results of measurements performed in an office room in the first Polish passive commercial office building during four months of normal operation. They were used to calculate parameters describing thermal comfort: vertical air temperature profile, floor surface temperature, predicted mean vote (PMV) and predicted percent of dissatisfied (PPD). Obtained results confirmed good thermal conditions in the analysed room. The average temperature of the floor’s surface varied from 20.6 °C to 26.2 °C. The average vertical air temperature, calculated for working days, was from 22.5 °C to 23.1 °C. The temperature difference between the floor and 5 cm below the ceiling was from −0.9 °C to 6.3 °C. The PMV index varied from 0.52 to 1.50 indicating ‘slightly warm’ sensation, in spite of ‘neutral’ reported by employees. Also measured cooling and heating energy consumption was presented. The performed measurements confirmed the ability of thermally activated building system (TABS) to keep good thermal conditions.

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.

Evaluation of Indoor Climate in Big Lecture Hall

2019 ◽  
Vol 887 ◽  
pp. 475-483
Author(s):  
Mária Budiaková
Keyword(s):  
Thermal Comfort ◽  
Ventilation System ◽  
Winter Season ◽  
Point Of View ◽  
Lecture Hall ◽  
Experimental Measurements ◽  
Optimal Parameters ◽  
Indoor Climate ◽  
Air Velocity ◽  
Operation System

The paper is oriented on the evaluation of the indoor climate in the big lecture hall. Providing the optimal parameters of the thermal comfort and the CO2 concentration is immensely important for the students in the interiors of a university. Meeting these parameters is inevitable not only from physiological point of view but also for achieving the desirable students' performance. The high CO2 concentration is related to incorrect and insufficient ventilation in the lecture hall and causes distractibility and feeling of tiredness of students. Experimental measurements were carried out in the winter season in 2016 in the big lecture hall in order to evaluate the thermal comfort and the CO2 concentration. The device Testo 480 was used for the measurements. Obtained values of air temperature, air relative humidity, air velocity, CO2 concentration are presented in the charts. Mechanical ventilation system and operation system of the big university lecture hall were evaluated on the basis of the parameters of the thermal comfort and on the basis of the CO2 concentration. Based on the findings, design recommendations for new big university lecture halls are derived. Furthermore, there are presented recommendations how to operate the existing big university lecture halls.

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.

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, thermal sensation and skin temperature measurements using demand-controlled ventilation for individual cooling

2020 ◽  
Vol 172 ◽  
pp. 06001
Author(s):  
Håkon Solberg ◽  
Kari Thunshelle ◽  
Peter Schild
Keyword(s):  
Thermal Comfort ◽  
Skin Temperature ◽  
Energy Demand ◽  
Thermal Sensation ◽  
Air Velocity ◽  
Climate Chamber ◽  
Biometric Data ◽  
Ongoing Research ◽  
Demand Controlled Ventilation ◽  
The Relationship

An increasing part of modern building's energy demand is due to cooling. An ongoing research project investigates the possibility to reduce the energy consumption from cooling by utilizing an individually controlled active ventilation diffuser mounted in the ceiling. This study looks at thermal sensation and thermal comfort for 21 test persons exposed to an innovative user controlled active ventilation valve, in a steady and thermally uniform climate chamber. Furthermore, the relationship between biometric data from the test persons skin temperature and sweat, and the test persons thermal sensation scores has been investigated. Each test person was exposed to three different room temperatures in the climate chamber, 24°C, 26°C and 28°C respectively, to simulate typical hot summer conditions in an office in Norway. At a room temperature of 26°C it was possible to achieve acceptable thermal comfort for most test persons with this solution, but higher air velocity than 0.75 m/s around the test persons bodies at room temperatures of 28°C is required to ensure satisfactory thermal comfort.

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