scholarly journals CFD PREDICTIONS OF INDOOR AIR MOVEMENT INDUCED BY COLD WINDOW SURFACES/VĖSIŲ LANGŲ PAVIRŠIŲ SUKELIAMO ORO JUDĖJIMO TYRIMAI PASITELKIANT KOMPIUTERINIO MODELIAVIMO METODUS

2008 ◽  
Vol 14 (1) ◽  
pp. 29-38 ◽  
Author(s):  
Andrius Jurelionis ◽  
Edmundas Isevičius
Keyword(s):  
Thermal Comfort ◽  
Residential Buildings ◽  
Air Velocity ◽  
Thermal Discomfort ◽  
Transmission Coefficients ◽  
Air Movement ◽  
Computational Fluid Dynamics Cfd ◽  
U Value ◽  
Positive Effect ◽  
Occupied Zone

During the past decades, large windows and glazed façades have become an important part of modern architecture and they are designed frequently in both public and residential buildings. However, besides the positive effect of such a design on building occupants, large windows may cause thermal discomfort. Cold inner window surface may generate draught in the occupied zone. Thermal comfort in rooms is usually assessed by measuring air temperature, relative humidity, air velocity and heat transfer due to radiation. In this study computational fluid dynamics (CFD) methods have been used to investigate these phenomena. Air movement caused by cold vertical window surfaces was evaluated and its impact on thermal comfort conditions in rooms have been outlined. Windows of different constructions and having different heat transmission coefficients were modelled (2.4, 1.6 and 1.0 W/m2K). CFD predictions showed that even in cases of low window thermal transmittance coefficient (U value), thermal discomfort conditions may appear in the room if the height of the window is more than 2.0 meters. Santrauka Dideli langai ir stiklo fasadai tapo neatsiejama šiuolaikiškos architektūros dalis. Jie projektuojami ne tik visuomeniniuose, bet ir individualiuose namuose. Nekalbant apie teigiamus tokios architektūros aspektus, didelių matmenų langai gali tapti šiluminio diskomforto priežastis. Už patalpos orą vėsesnis vidinis stiklo paviršius sukelia žemyn nukreiptą oro srautą, kuris tam tikru greičiu patenka į žmonių gyvenamąją arba darbo zoną. Vėsių stiklo paviršių sukeltų oro srovių intensyvumas priklauso nuo lango šiluminių savybių, jo konstrukcijos bei šildymo prietaisų įrengimo vietų. Dažniausiai mikroklimato sąlygos patalpose vertinamos matuojant oro temperatūrą, santykinį drėgnį, oro judrumą ir šilumos mainus spinduliavimu. Straipsnyje pristatomas tyrimas, kuriam buvo pasitelktas kompiuterinis oro judėjimo modeliavimas (skaitiniai skysčių ir dujų dinamikos metodai). Buvo tiriama oro judėjimo patalpose priklausomybė nuo langų bei stiklo fasadų konstrukcijų ir šiluminių savybių. Modeliuojant įvertinti trys langų tipai, kurių šilumos perdavimo koeficientų vertės: 2,4; 1,6 ir 1,0 W/m²K. Rezultatai parodė, kad net ir mažiausiai šilumai laidūs langai gali sukelti neleistiną oro judėjimą patalpose, jei jų aukštis viršija 2 metrus.

scholarly journals Study on the Performance of Adjustable Platform Screen Door in Subway Stations

2020 ◽  
Vol 172 ◽  
pp. 24008
Author(s):  
Su Ziyi ◽  
Li Xiaofeng ◽  
Zhang Yue
Keyword(s):  
Thermal Comfort ◽  
Cfd Simulation ◽  
Rapid Progress ◽  
Comfort Zone ◽  
Thermal Discomfort ◽  
Warmth Index ◽  
Computational Fluid Dynamics Cfd ◽  
Subway Stations ◽  
Arrival Pattern ◽  
Occupied Zone

In the last decades, the construction of subway systems has been in rapid progress in metropolis. Former studies have pointed out that substantial amount of energy is consumed by subway stations. Thus, the adjustable platform screen door (APSD) system is widely adopted, which is characterized by the energy-saving in both the cooling season and the transitional season. However, the installation of APSD system might result in thermal discomfort for passengers, which lacks investigation. This study aims to study the performance on the thermal comfort of subway station with APSD system. In this process, Computational Fluid Dynamics (CFD) Simulation was conducted using PHOENICS to obtain the velocity and temperature distribution under 3 kinds of train arrival patterns. Furthermore, Relative Warmth Index (RWI) was used to assess thermal comfort. The results show that the velocities of the platform and station hall are below 2.5m/s and 3.7m/s respectively, which is closely related to the train arrival pattern. With regard to the platform occupied zone, the RWI is between 0.04 to 0.19, which is almost within the thermal comfort zone according to the ASHRAE comfort classification. Nevertheless, for the occupied zone of the hall, the RWI is between 0.15 to 0.52, indicating relatively warm.

scholarly journals Modeling the Evolution of Construction Solutions in Residential Buildings’ Thermal Comfort

2021 ◽  
Vol 11 (5) ◽  
pp. 2427
Author(s):  
Inês F. G. Reis ◽  
António Figueiredo ◽  
António Samagaio
Keyword(s):  
Thermal Comfort ◽  
Phase Change Materials ◽  
Residential Buildings ◽  
Thermal Inertia ◽  
Thermal Fluctuations ◽  
Energy Performance ◽  
Regulatory Requirements ◽  
Thermal Discomfort ◽  
High Thermal Inertia ◽  
Global Energy Consumption

The evolution of the construction sector over the years has been marked by the replacement of high thermal inertia mass constructions by increasingly lighter solutions that are subject to greater thermal fluctuations and, consequently, thermal discomfort. To minimize these effects, energy demanding space conditioning technologies are implemented, contributing significantly to the sector’s share of global energy consumption. Enhanced constructive solutions involving phase-change materials have been developed to respond to the constructive thermal inertia loss, influencing buildings’ thermal and energy performance. This work aims to model the evolution of the construction over the last decades to understand to what extent constructive characteristics influence the occupants’ thermal comfort. For this purpose, typical and enhanced solutions representing distinct constructive periods were simulated using the EnergyPlus® software through its graphical interface DesignBuilder® and the thermal comfort of the different solutions was evaluated using the adaptive model for thermal comfort EN16798-1. The main results reveal that more restraining regulatory requirements are indeed mitigating thermal discomfort situations. However, overheating phenomena can rise, creating worrying consequences in the short-medium term. Thus, countries with mild climates such as Portugal, must pay special attention to these effects, which may be aggravated by climate change.

scholarly journals Numerical Investigation of Thermal Comfort in an Aircraft Passenger Cabin

2019 ◽  
Vol 111 ◽  
pp. 01027
Author(s):  
Sasan Sadrizadeh
Keyword(s):  
Fluid Dynamics ◽  
Thermal Comfort ◽  
Thermal Sensation ◽  
Numerical Study ◽  
Small Variation ◽  
Air Velocity ◽  
Limited Effect ◽  
Considerable Impact ◽  
Computational Fluid Dynamics Cfd ◽  
Passenger Cabin

This study presents the results of a pilot numerical study of the thermal comfort in the aircraft passenger cabin. The computations have been performed using the Computational Fluid Dynamics (CFD) technique. The overall thermal comfort at temperatures of 15 °C – 20 °C was discussed based on the PMV (Predicted Mean Vote) and PPD (Predicted Percentage of Dissatisfied) indexes. Results indicate that the air velocity and its direction toward the passengers have a considerable impact on their thermal comfort. However, a small variation in temperature has a limited effect on thermal sensation and thus do not jeopardize the overall thermal comfort.

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.

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.

Thermal Comfort Study Based on Airflow within a Passenger Compartment

2015 ◽  
Vol 730 ◽  
pp. 109-112 ◽  
Author(s):  
Li Ping Xiang ◽  
Han Qing Wang
Keyword(s):  
Thermal Comfort ◽  
Indoor Environment ◽  
Outlet Temperature ◽  
Passenger Compartment ◽  
Air Velocity ◽  
Head Region ◽  
Index Distribution ◽  
Airflow Field ◽  
Predicted Values ◽  
Occupied Zone

It is important to analyze the temperature, airflow field, PMV-PPD index distribution within the passenger compartment to ameliorate the amenity and decrease consumption. A numerical model to assess the thermal comfort taking into account the different air velocity. This paper uses commercial software FLUENT to simulate 3-D temperature, PMV-PPD index distributions and flow field in a compartment passenger. The predicted results basically meet the requirement of thermal comfort except the local temperature around the lower region and the local air velocities around passengers’ head region. When the air-outlet temperature is 20 °C, air-outlet velocity 4 m/s is agreed to the thermal comfort. PMV index are about -0.4-0.6, and PPD index is less than 10%, which is agreed with passenger’s thermal comfort. The predicted values illustrate the uniformity of indoor environment in the occupied zone.

scholarly journals INFLUENCE OF MASS ‘U’ FORM IN LINE UP FORMATION TOWARDS AIR MOVEMENT ON SUPPORTING THERMAL COMFORT IN OUTSIDE SPACE OF APARTMENT LANDMARK RESIDENCE, BANDUNG

2019 ◽  
Vol 3 (04) ◽  
pp. 398-413
Author(s):  
Gabriela Marcella ; Nancy Yusnita Nugroho
Keyword(s):  
Thermal Comfort ◽  
Wind Velocity ◽  
Outer Space ◽  
Thermal Conditions ◽  
Simulation Software ◽  
Comfort Level ◽  
Air Velocity ◽  
Air Movement ◽  
The Masses ◽  
Mass Form

Abstract- Indonesia with the characteristics of tropical climate requires control in design to achieve thermal comfort both in outside space and inside space. One of the factors that can affect thermal comfort is the pattern of air movement and air velocity. Landmark Residence Apartment is one of the new apartments in Bandung, with mass ‘U’ form in line up of new partially awakened. The newly constructed 'U' mass formation forms the characteristic of the two different masses, the space side in the closed A mass with the characteristic of the centered space as well as the side in the open mass B. this apartment become an object of research to determine the factors of order and mass form to the characteristics of air movement as well as thermal comfort in the outside space as a space of activities in residents. The method used in this research is descriptive-quantitative with simulation software Flow Design to know the air movement and measurement of thermal comfort factor at the point of population and sample which have been determined. This thermal factor will be analyzed using CET Nomogram method, so it generates thermal comfort level in outer space which will be associated with order and mass form of apartment. By using analysis of air movement patterns and CET Nomogram, it is seen that thermal comfort level in the outside space Landmark Residence apartment is more affected by wind velocity. The mass 'U' form with the back to wind direction will produce high wind velocity on the outside space of the building's side, while on the inner side of the 'U' form will form the shadow of the wind and the pattern of turbulence air movement affecting the achievement of different thermal conditions. The 'U' mass sequence lined up can also cause air movement on the inner side of closed A mass not getting enough air movement compared to open mass B with better airflow pattern. The pattern of air movement on the inner side of mass A can be at any time higher when the wind velocity enters the gap between the masses.  Key Words: apartment, outside space, mass ‘U’ form in line up, air movement, thermal comfort.

scholarly journals Barriers To The Adoption Of Environmentally Sustainable Design Methods In Residential Buildings. The Architects’ And Building Owners’ Perspectives In Four Nigerian States

2021 ◽  
Author(s):  
Tamaraukuro Amasuomo
Keyword(s):  
Energy Efficiency ◽  
Thermal Comfort ◽  
Sustainable Design ◽  
Residential Buildings ◽  
Economic Benefits ◽  
Design Methods ◽  
Research Approach ◽  
Thermal Discomfort ◽  
Environmentally Sustainable ◽  
Lack Of Knowledge

<p><b>This thesis investigates Nigerian architects’ and building owners’ perceptions of Environmentally Sustainable Design Methods (ESD) to identify barriers preventing ESD adoption for providing thermal comfort and energy efficiency in Nigerian residential buildings. Most of the surveyed architects and building owners agree on the problem of thermal discomfort in Nigerian residential dwellings. However, the results show that architects and building owners opt for non-sustainable methods for addressing this problem. This study aims to understand why architects and building owners are choosing non-sustainable methods. To achieve this aim, the study investigates barriers preventing the widespread adoption of ESD in Nigeria to understand why ESD is not generally adopted as a preferred solution for addressing the problem of thermal discomfort.</b></p> <p>The thesis reports on a three-stage evaluation of current barriers to environmentally sustainable design methods in four Nigeria states (Lagos, Abuja, Rivers, and Bayelsa) and concludes by providing basic ways through which ESD could be adopted for ensuring thermal comfort and energy efficiency. A mixed-method research approach was utilised due to its robustness in addressing the research objectives. Stage 1 involved the distribution and analysis of questionnaires from 130 architects; stage 2 undertook semi-structured interviews with 21 architects; stage 3 undertook the distribution of questionnaires to 142 building owners and a visual physical examination of their respective buildings. The results showed that the barriers preventing the adoption of ESD in Nigeria include: a lack of technological development, cost of building construction and operation, public perception, poor governance, and most importantly, a lack of knowledge on the means of adopting ESD. The results from the interview with architects on the main obstacles to ESD showed that a lack of knowledge had the highest citing of 85%, poor governance a citing of 66%, economic factors 57%, and social factors 52%, respectively. These figures were similar to the results from the building owner’s survey.</p> <p>Given the lack of knowledge on adopting ESD, the thesis provides an explicit but straightforward set of ESD strategies that would add to the existing body of knowledge on ESD, resolve the lack of knowledge, and make ESD easily applicable. It is recommended that the Nigerian government and related institutions set a clear strategy for educating the public on the benefits and means of adopting a pro-sustainable culture. This strategy would include highlighting the importance of environmental protection and ESD, the possible environmental and health implications of environmental degradation, and the long-term economic benefits of sustainable design. Such a strategy should include a structured system of information dissemination through formal and informal mediums such as public campaigns and social media to reach a wide-ranging audience. The research findings identify the range of possible barriers preventing the attainment of a sustainable environment in Nigeria and other countries with similar issues. They also form the basis for an action plan.</p>

scholarly journals PENGARUH MATERIAL RUANG PADA KENYAMANAN TERMAL RUANG MEMBATIK YANG MENGGUNAKAN SKYLIGHT STUDI KASUS: RUMAH BATIK KATURA, PLERED, CIREBON (The Effect of Space Material to Thermal Comfort of Batik Craftsperson Room with Skylight, Case Study: Batik Katura H

2015 ◽  
Vol 13 (2) ◽  
pp. 81
Author(s):  
Dyah Nurwidyaningrum ◽  
Hidjan A.G ◽  
Rita Farida
Keyword(s):  
Thermal Comfort ◽  
Program Analysis ◽  
Material Properties ◽  
Research Method ◽  
Thermal Problem ◽  
Air Movement ◽  
U Value ◽  
Preliminary Study ◽  
Space Material

Problem in using skylight for batik craftsperson is discomfort thermal that could bother batik craftsperson work. The skylight which used in the preliminary study was declared really effective for day lighting batik craftsperson work plane. This must be proved to comfort thermal problem. Questions in this research is how to solve discomfort thermal in the batik craftsperson space caused use skylight to natural light. The research method uses phenomenology and simulation ecotect program. Analysis about the condition of exixting show discomfort thermal because temperature is 32,79-35,01oC, still overheat than 27,1oC according to SNI 03-6572-2001. The analysis on alternatif 1 showed that the decrease in temperature 2,08oC be 30,01oC in June, but still too hot however these materials has have low U-value. Further analysis with the changes material properties, show reduced from the fist alternative 4,27oC become 28,52oC. Although this value has not yet reach 27,1oC l in SNI but thermal comfort could be achieved by air movement (mechanical fan) that can make people feel 2 oC temperature decrease from the real.

scholarly journals Analytical Studies on Levels of Thermal Comfort in Typical Low-Income Houses Design

2014 ◽  
Vol 5 (1) ◽  
pp. 28-33
Author(s):  
S.H. Ibrahim, ◽  
A. Baharun ◽  
M.N. Mohd Nawi ◽  
E. Junaidi
Keyword(s):  
Thermal Comfort ◽  
Low Income ◽  
Airflow Rate ◽  
Mean Radiant Temperature ◽  
Air Velocity ◽  
Door Opening ◽  
Air Movement ◽  
Air Temperatures ◽  
Radiant Temperature ◽  
Housing Estates

 This paper investigates the present situation of thermal comfort in typical low-income houses located in Betong and Saratok, Sarawak, Malaysia. Investigations were carried out by measuring airflow rate, temperature, relative humidity and mean radiant temperature at specific points in one chosen house of each district. Different low-income housing estates were chosen for comparisons due to the different location and position of each house. Although both of these low- income houses have similarity in design but differs in layout arrangement. Results are presented and analyzed using Corrected Effective Temperature (CET) index in two different window and door opening configurations. The results show that the modern low-income house is thermally uncomfortable under certain conditions. High internal air temperatures occurred when doors and windows were closed combined with low air velocity contributes to thermally uncomfortable environment. Once all doors and windows were opened, allowing the air movement to increase, thermal comfort was achieved although air temperatures remained high.

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