scholarly journals Achieving wind comfort through window design in residential buildings in cold climates, a case study in Tabriz city

Author(s):  
Atefeh Tamaskani Esfahankalateh ◽  
Mohammad Farrokhzad ◽  
Ommid Saberi ◽  
Amirhosein Ghaffarianhoseini

Abstract Air movement affects thermal comfort both by increasing evaporative loss through the skin and heat transfer between the body and surrounding environment through convection. Generally, in cold climates, it is best to avoid wind to better control the thermal environment. However, crafted passive airflow is essential for providing fresh air and natural ventilation at certain times of year. The use of a window of the right size and location in a cold climate is also indispensable. In this study, the wind speed was calculated for the height of a residential building in the city of Tabriz. A computational fluid dynamics simulation was used to calculate the inflow air speed for each window and the comfort conditions were compared. The findings determined the months where window openings can be used to enhance thermal comfort. The analysis shows how the direction and shape of the window play a major role in directing outdoor air flow indoors at the right time in the right quantity. East- and west-facing windows are most favorable and north- and south-facing windows can only be used in some months. This shows how building designers can quantify the effect of window design in each climate for the occupant’s comfort.

2021 ◽  
Author(s):  
Christopher L. K. Wang

As sleep is unconscious, the traditional definition of thermal comfort with conscious judgment does not apply. In this thesis sleep thermal comfort is defined as the thermal condition which enables sleep to most efficiently rejuvenate the body and mind. A comfort model was developed to stimulate the respective thermal environment required to achieve the desired body thermal conditions and a new infrared sphere method was developed to measure mean radiant temperature. Existing heating conditions according to building code conditions during sleeping hours was calculated to likely overheat a sleeping person and allowed energy saving potential by reducing nighttime heating set points. Experimenting with existing radiantly and forced air heated residential buildings, it was confirmed that thermal environment was too hot for comfortable sleep and that the infrared sphere method shows promise. With the site data, potential energy savings were calculated and around 10% of energy consumption reduction may be achieved during peak heating.


2011 ◽  
Vol 20 (1) ◽  
pp. 101-111 ◽  
Author(s):  
Baizhan Li ◽  
Wei Yu ◽  
Meng Liu ◽  
Nan Li

Yangtze River Valley is situated within the Hot Summer and Cold Winter zone, and residents in this region of China would require HVAC system to alleviate thermal comfort conditions, although this is tempered by the Design Code (DBJ50-071-2007) for energy efficiency. A 1-year survey of about 200 residential homes was carried out in eight cities covering the breadth of the region. The acceptable temperature range for the residents in this area was 16.3—28.1°C and the thermal neutral temperature was found to be 27.6°C in summers and 17.5°C in winters. People in different area can vary in their adaptability and comfortableness. Therefore, there is a need to investigate the national comfort parameter introduced in the Code for Design of Heating and Ventilation and Air Conditioning (GB50019-2003). The results found that if air-conditioning system was set to 27.5°C instead of 26°C as required by GBJ19-87: Design Standard of Heating and Ventilation and Air Conditioning, a 16.5% saving of energy consumption could be achieved. The findings demonstrated the role of natural ventilation in the expansion of the thermal comfort zone for the residents, especially during the summer seasons. A climatic adaptability model has been established by this study to contribute to the passive climatic design strategies for a better economic and energy efficiency of buildings.


2020 ◽  
Vol 3 (1) ◽  
pp. p1
Author(s):  
Jad Hammoud ◽  
Elise Abi Rached

The increasing of energy demands has considerably increased the requirements for new and traditional buildings in different climate zones. Unprecedented heat waves have increased climate temperature, in particular, in moderate climate zones such as Lebanon. In Beirut, only the residential sector consumes 50% of total electricity consumption. HVAC (Heating, Ventilation and Air conditioning) systems are used to reach acceptable thermal comfort levels in the new residential buildings. In case of the traditional bourgeoisie houses in Beirut, there are no discussions about the use of HVAC systems to achieve the required thermal comfort level. Thus, to reach an acceptable thermal comfort level, these houses which already contain natural ventilation system shall adapt the modern thermal comfort requirements and thermal comfort strategies and technologies where their architectural features and existing materials condition the available solutions. In order to identify the best options within the possible intervention lines (envelopes, passive strategies, equipment, renewable energy systems), it is necessary to perceive the real performance of this type of houses. In this context, the article presents the results of the study of thermal performance and comfort in a three case studies located in Beirut. Detailed field data records collected are analyzed, with a view to identify the indoor thermal environment with respect to outdoor thermal environment in different seasons. Monitoring also included measurement of hygrothermal parameters and surveys of occupant thermal sensation.


2021 ◽  
Author(s):  
Christopher L. K. Wang

As sleep is unconscious, the traditional definition of thermal comfort with conscious judgment does not apply. In this thesis sleep thermal comfort is defined as the thermal condition which enables sleep to most efficiently rejuvenate the body and mind. A comfort model was developed to stimulate the respective thermal environment required to achieve the desired body thermal conditions and a new infrared sphere method was developed to measure mean radiant temperature. Existing heating conditions according to building code conditions during sleeping hours was calculated to likely overheat a sleeping person and allowed energy saving potential by reducing nighttime heating set points. Experimenting with existing radiantly and forced air heated residential buildings, it was confirmed that thermal environment was too hot for comfortable sleep and that the infrared sphere method shows promise. With the site data, potential energy savings were calculated and around 10% of energy consumption reduction may be achieved during peak heating.


2012 ◽  
Vol 518-523 ◽  
pp. 4461-4465
Author(s):  
Li Li

The good and comfortable environment is beneficial to the health, and can improve working efficiency, make people imbued with more creativity. This means strengthening the competitiveness, increase economic efficiency. So, creating the good building environment not merely has a meaning on technology, and has social effect and economic meaning. In order to understand the situation of indoor thermal environment of the seaside residential building generally, a field measurement on the condition of summer was made in Xiamen from the last ten days of July to the first ten day of Aug, 2005, 2006 and 2008. Test the thermal environment and investigate the thermal comfort in residential buildings of natural ventilation condition, analyze the main influence factors of indoor thermal environment, and evaluate indoor thermal comfort with effective temperature (ET). The curves of indoor air temperature and relative humidity reflect the character of high temperature and high relative humidity in summer in Xiamen residential buildings. Discuss the methods of building energy saving. Suggest that, for seaside city in hot days, the natural ventilation and interval natural ventilation should be the main fundamental methods of improving the resident building thermal environment.


Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 696
Author(s):  
Eun Ji Choi ◽  
Jin Woo Moon ◽  
Ji-hoon Han ◽  
Yongseok Yoo

The type of occupant activities is a significantly important factor to determine indoor thermal comfort; thus, an accurate method to estimate occupant activity needs to be developed. The purpose of this study was to develop a deep neural network (DNN) model for estimating the joint location of diverse human activities, which will be used to provide a comfortable thermal environment. The DNN model was trained with images to estimate 14 joints of a person performing 10 common indoor activities. The DNN contained numerous shortcut connections for efficient training and had two stages of sequential and parallel layers for accurate joint localization. Estimation accuracy was quantified using the mean squared error (MSE) for the estimated joints and the percentage of correct parts (PCP) for the body parts. The results show that the joint MSEs for the head and neck were lowest, and the PCP was highest for the torso. The PCP for individual activities ranged from 0.71 to 0.92, while typing and standing in a relaxed manner were the activities with the highest PCP. Estimation accuracy was higher for relatively still activities and lower for activities involving wide-ranging arm or leg motion. This study thus highlights the potential for the accurate estimation of occupant indoor activities by proposing a novel DNN model. This approach holds significant promise for finding the actual type of occupant activities and for use in target indoor applications related to thermal comfort in buildings.


Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4530
Author(s):  
Youcef Bouzidi ◽  
Zoubayre El Akili ◽  
Antoine Gademer ◽  
Nacef Tazi ◽  
Adil Chahboun

This paper investigates adaptive thermal comfort during summer in medical residences that are located in the French city of Troyes and managed by the Association of Parents of Disabled Children (APEI). Thermal comfort in these buildings is evaluated using subjective measurements and objective physical parameters. The thermal sensations of respondents were determined by questionnaires, while thermal comfort was estimated using the predicted mean vote (PMV) model. Indoor environmental parameters (relative humidity, mean radiant temperature, air temperature, and air velocity) were measured using a thermal environment sensor during the summer period in July and August 2018. A good correlation was found between operative temperature, mean radiant temperature, and PMV. The neutral temperature was determined by linear regression analysis of the operative temperature and Fanger’s PMV model. The obtained neutral temperature is 23.7 °C. Based on the datasets and questionnaires, the adaptive coefficient α representing patients’ capacity to adapt to heat was found to be 1.261. A strong correlation was also observed between the sequential thermal index n(t) and the adaptive temperature. Finally, a new empirical model of adaptive temperature was developed using the data collected from a longitudinal survey in four residential buildings of APEI in summer, and the obtained adaptive temperature is 25.0 °C with upper and lower limits of 24.7 °C and 25.4 °C.


2021 ◽  
Vol 8 (1) ◽  
pp. 23
Author(s):  
Erna Meutia ◽  
Laina Hilma Sari

The Gayo Highland is one of the districts in Aceh Province, Sumatra. Due to the topography, this area has a lower  temperature compared than the flat and coastal areas in Aceh. The thermal comfort that is felt is based on a person's mental condition and how he expresses his satisfaction with his thermal environment. In other words, it shows how humans adapt to their thermal environment. Thermal comfort based on human adaptation is known as adaptive thermal comfort. The form of dwelling for the Gayo Highland community has shifted and changed from traditional dwelling to Transitional and Modern forms that influence the Gayo Highland community's adaptation to achieve thermal comfort. Therefore, this paper aims to investigate the house design in Gayo highland in providing warmth to the occupants naturally in the cold environment. Another aim of this study is to investigate the people's habits in warming up the body to deal with the low air temperature in the area.  This study shows how the local people adapt themselves through the house element and daily habit to gain the internal thermal comfort.


Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8013
Author(s):  
Tony-Andreas Arntsen ◽  
Bozena Dorota Hrynyszyn

Window design affects the overall performance of a building. It is important to include window design during the initial stages of a project since it influences the performance of daylight and thermal comfort as well as the energy demand for heating and cooling. The Norwegian building code facilitates two alternative methods for achieving a sufficient daylight, and only guidelines for adequate indoor thermal comfort. In this study, a typical Norwegian residential building was modeled to investigate whether the criteria and methods facilitate consistent and good performance through different scenario changes and furthermore, how the national regulations compare to European standards. A better insulated and more air-tight building has usually a lower annual heating demand, with only a marginal decrease in the daylight performance when the window design is unchanged. A more air-tight construction increases the risk of overheating, even in cold climates. This study confirms that a revision of the window design improves the overall performance of a building, which highlights the importance of proper window design. The pursuit of lower energy demand should not be at the expense of indoor thermal comfort considering the anticipated future weather conditions. This study indicates that criteria for thermal comfort and daylight, if clearly defined, can affect the energy demand for heating and cooling, as well as the indoor climate positively, and should be taken into account at the national level. A comparison between the national regulations and the European standards was made, and this study found that the results are not consistent.


2020 ◽  
Vol 15 (3) ◽  
pp. 163-170
Author(s):  
Rajan KC ◽  
Hom Bahadur Rijal ◽  
Masanori Shukuya ◽  
Kazui Yoshida

The energy use in residential dwellings has been increasing due to increasing use of modern electric appliances to make the lifestyle easier, entertaining and better. One of the major purposes of indoor energy use is for improving indoor thermal environment for adjusting thermal comfort. Along with the use of passive means like the use of mechanical devices, the occupants in any dwellings use active means such as the use of natural ventilation, window opening, and clothing adjustment. In fact, the use of active means when the outdoor environment is good enough might be more suitable to improve indoor thermal environment than the use of mechanical air conditioning units, which necessarily require electricity. Therefore, the people in developing countries like Nepal need to understand to what extent the occupants can use active means to manage their own indoor thermal comfort. The use of active means during good outdoor environment might be an effective way to manage increasing energy demand in the future. We have made a field survey on the occupants’ adaptive behaviors for thermal comfort in a Japanese condominium equipped with Home Energy Management System (HEMS). Online questionnaire survey was conducted in a condominium with 356 families from November 2015 to October 2016 to understand the occupants’ behaviors. The number of 17036 votes from 39 families was collected. The indoor air temperature, relative humidity and illuminance were measured at the interval of 2-10 minutes to know indoor thermal environmental conditions. The occupants were found using different active behaviors for thermal comfort adjustments even in rather harsh summer and winter. Around 80% of the occupants surveyed opened windows when the outdoor air temperature was 30⁰C in free running (FR) mode and the clothing insulation was 0.93 clo when the outdoor air temperature was 0⁰C. The result showed that the use of mechanical heating and cooling was not necessarily the first priority to improve indoor thermal environment. Our result along with other results in residential buildings showed that the adaptive behaviors of the occupants are one of the primary ways to adjust indoor thermal comfort. This fact is important in enhancing the energy saving building design.


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