User Thermal Comfort in Historic Buildings: Evaluation of the Potential of Thermal Mass, Orientation, Evaporative Cooling and Ventilation

The study investigated the level of thermal comfort in historical buildings located at a relatively high altitude in the Arabian Desert of Saudi Arabia. The study focused on the impact of the use of thermal mass and orientation on the level of thermal performance at Shubra and Boqri Palaces. Qualitative and quantitative analyses were used in this study, including a questionnaire interview with architecture experts living at the relatively high altitude of Taif city, to obtain data and information from local experts. The computer software TAS EDSL was used along with on-site equipment, such as thermal imaging cameras and data loggers, to observe the physical conditions of the building in terms of its thermal performance. The study revealed that the experts’ age and years of experience were important aspects while collecting data from them during the survey. The use of thermal mass had a slight impact on the indoor air temperature as well as the energy consumption, but it helped in providing thermal comfort. Use of ventilation can improve thermal comfort level. Evaporative cooling technique has a considerable impact on reducing indoor air temperature with 4 °C drop, improving the thermal comfort sensation level. The novelty of this work is that, it links the outcomes of qualitative results of experts with field monitoring as well as computer modelling. This can contribute as method to accurately collect data in similar case studies.

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Towards Pedestrian Microclimatic Comfort: A Rapid Predication Model for Street Winds and Pedestrian Thermal Sensation

Nano LIFE ◽

10.1142/s1793984418400068 ◽

2018 ◽

Vol 08 (02) ◽

pp. 1840006

Author(s):

Jing Li ◽

Mengnan Qi ◽

Qiuhua Duan ◽

Lei Huo ◽

Julian Wang

Keyword(s):

Wind Speed ◽

Built Environment ◽

Thermal Comfort ◽

Air Temperature ◽

Goodness Of Fit ◽

Comfort Level ◽

Outdoor Thermal Comfort ◽

Design Parameters ◽

Rapid Urbanization ◽

The Impact

Significant changes in the urban built environment have occurred due to rapid urbanization and increases in the urban population. Such alterations may produce environmental health-related issues such as urban heat stress, air pollution and traffic noise. This research undertook a field study to collect data including urban design parameters, micro-environmental factors and city climatic information. This work was conducted over a two-year period on three pedestrian streets located in high-density urban areas in Beijing. These areas were selected in order to study the influences of urban street canyon texture within a particular geometric layout, wind flow corridors and variations in air temperature on pedestrian microclimatic comfort. The results will facilitate the work of urban planners by providing them with information for use in improving outdoor thermal comfort through their designs. A total of 60[Formula: see text]485 samples were organized into training, validation and test sets. We confirmed our hypothesis that internal wind speed ([Formula: see text] is attributable mainly to the urban texture coefficient ([Formula: see text], air temperature ([Formula: see text] and leading-in wind speed ([Formula: see text]. The model was tested using the test data collected onsite, which demonstrated a very accurate goodness-of-fit; the model achieved an R-squared value of 0.82, which meant that [Formula: see text] as a dependent variable was 82% correlated to the three predictors as independent variables. With this computer simulation, urban planners can now predict and visualize the impact of changes on the built environment in terms of either the direction of solar radiation received or increases in wind speed, in return for the desired thermal comfort level for residents of the neighborhood.

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Energy-saving potential of intermittent heating system: Influence of composite phase change wall and optimization strategy

Energy Exploration & Exploitation ◽

10.1177/0144598720969217 ◽

2020 ◽

pp. 014459872096921

Author(s):

Yanru Li ◽

Enshen Long ◽

Lili Zhang ◽

Xiangyu Dong ◽

Suo Wang

Keyword(s):

Energy Consumption ◽

Thermal Comfort ◽

Phase Change ◽

Air Temperature ◽

Indoor Air ◽

Thermal Environment ◽

Optimization Strategy ◽

Indoor Thermal Environment ◽

Indoor Thermal Comfort ◽

Intermittent Heating

In the Yangtze River zone of China, the heating operation in buildings is mainly part-time and part-space, which could affect the indoor thermal comfort while making the thermal process of building envelope different. This paper proposed to integrate phase change material (PCM) to building walls to increase the indoor thermal comfort and attenuate the temperature fluctuations during intermittent heating. The aim of this study is to investigate the influence of this kind of composite phase change wall (composite-PCW) on the indoor thermal environment and energy consumption of intermittent heating, and further develop an optimization strategy of intermittent heating operation by using EnergyPlus simulation. Results show that the indoor air temperature of the building with the composite-PCW was 2–3°C higher than the building with the reference wall (normal foamed concrete wall) during the heating-off process. Moreover, the indoor air temperature was higher than 18°C and the mean radiation temperature was above 20°C in the first 1 h after stopping heating. Under the optimized operation condition of turning off the heating device 1 h in advance, the heat release process of the composite-PCW to the indoor environment could maintain the indoor thermal environment within the comfortable range effectively. The composite-PCW could decrease 4.74% of the yearly heating energy consumption compared with the reference wall. The optimization described can provide useful information and guidance for the energy saving of intermittently heated buildings.

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Thermal history and comfort in a Brazilian subtropical climate: a 'cool' addiction hypothesis

Ambiente Construído ◽

10.1590/s1678-86212016000100057 ◽

2016 ◽

Vol 16 (1) ◽

pp. 7-20 ◽

Cited By ~ 13

Author(s):

Renata De Vecchi ◽

Christhina Maria Cândido ◽

Roberto Lamberts

Keyword(s):

Air Temperature ◽

Indoor Air ◽

Thermal History ◽

Air Conditioning ◽

Prolonged Exposure ◽

Temperature Fluctuations ◽

Subtropical Climate ◽

Indoor Thermal Comfort ◽

Air Speed ◽

The Impact

Abstract Currently, there is a rising trend for commercial buildings to use air conditioning to provide indoor thermal comfort. This paper focuses on the impact of prolonged exposure to indoor air-conditioned environments on occupants' thermal acceptability and preferences in a mixed-mode building in Brazil. Questionnaires were administered while indoor microclimatic measurements were carried out (i.e., air temperature, radiant air temperature, air speed and humidity). Results suggest significant differences in occupants' thermal acceptability and cooling preferences based on thermal history; differences were found between groups based on different physical characteristics (i.e., different gender and body condition). The findings also indicated a significant potential to implement temperature fluctuations indoors when occupants are exposed to air conditioning environments in warm and humid climates.

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An Interactive Task Conditioning System Featuring Personal Comfort Models and Non-Intrusive Sensing Techniques: A Field Study in Shanghai

Technologies ◽

10.3390/technologies9040090 ◽

2021 ◽

Vol 9 (4) ◽

pp. 90

Author(s):

Siliang Lu ◽

Erica Cochran Hameen

Keyword(s):

Thermal Comfort ◽

Field Study ◽

Air Temperature ◽

Indoor Air ◽

Thermal Environment ◽

Thermal Sensation ◽

New Paradigm ◽

Dynamic Task ◽

Current Task ◽

Open Plan

Heating, ventilation and air-conditioning (HVAC) systems play a key role in shaping office environments. However, open-plan office buildings nowadays are also faced with problems like unnecessary energy waste and an unsatisfactory shared indoor thermal environment. Therefore, it is significant to develop a new paradigm of an HVAC system framework so that everyone could work under their preferred thermal environment and the system can achieve higher energy efficiency such as task ambient conditioning system (TAC). However, current task conditioning systems are not responsive to personal thermal comfort dynamically. Hence, this research aims to develop a dynamic task conditioning system featuring personal thermal comfort models with machine learning and the wireless non-intrusive sensing system. In order to evaluate the proposed task conditioning system performance, a field study was conducted in a shared office space in Shanghai from July to August. As a result, personal thermal comfort models with indoor air temperature, relative humidity and cheek (side face) skin temperature have better performances than baseline models with indoor air temperature only. Moreover, compared to personal thermal satisfaction predictions, 90% of subjects have better performances in thermal sensation predictions. Therefore, personal thermal comfort models could be further implemented into the task conditioning control of TAC systems.

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Thermo-physical characteristics of building integrated phase change materials (PCM) and their applicability to energy efficient homes

10.32920/ryerson.14660997 ◽

2021 ◽

Author(s):

Omar Siddiqui

Keyword(s):

Compressive Strength ◽

Phase Change ◽

Phase Change Materials ◽

Energy Savings ◽

Physical Characteristics ◽

Comfort Level ◽

Thermal Mass ◽

Lower Phase ◽

Physical Test ◽

The Impact

The applicability of utilizing a variety of thermal mass including phase change materials with commonly used building materials is investigated through the use of simulations and physical testing. The thermal performance and occupant comfort potential of a novel solid-solid phase change material, known as Dal HSM, is compared and contrasted to commonly available forms of thermal mass. Detailed experimentation is conducted to successfully integrate Dal HSM with gypsum and concrete. The measurement of physical characteristics such as compressive strength and modulus of rupture is conducted to ensure that the PCM-composite compound retains the structural integrity to be utilized in a typical building. The use of thermal mass in the Toronto Net Zero house was found to contribute to energy savings of 10-15% when different types of thermal mass were used. The comfort level of the indoor occupants was also found to increase. The performance of Dal HSM was found to be comparable to a commercially available PCM known as Micronal in the heating mode. The cooling mode revealed that Dal HSM provided slightly lower energy savings when compared to Micronal due to a lower phase transition temperature and latent heat. The performance of physical test revealed a decrease in the compressive strength as the concentration of Dal HSM was increased in the PCM-gypsum specimens. Tests were also performed to analyze the impact of increasing the PCM concentration on the flexural strength of PCM-gypsum composite.

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Sensitivity Analysis of Occupant Preferences on Energy Usage in Residential Buildings

ASME 2021 15th International Conference on Energy Sustainability ◽

10.1115/es2021-64053 ◽

2021 ◽

Author(s):

Kaleb Pattawi ◽

Prateek Munankarmi ◽

Michael Blonsky ◽

Jeff Maguire ◽

Sivasathya Pradha Balamurugan ◽

...

Keyword(s):

Sensitivity Analysis ◽

Thermal Comfort ◽

Residential Buildings ◽

Electricity Consumption ◽

Cost Savings ◽

The United States ◽

Comfort Level ◽

Electrical Grid ◽

Home Energy Management ◽

The Impact

Abstract Residential buildings, accounting for 37% of the total electricity consumption in the United States, are suitable for demand response (DR) programs to support effective and economical operation of the power system. A home energy management system (HEMS) enables residential buildings to participate in such programs, but it is also important for HEMS to account for occupant preferences to ensure occupant satisfaction. For example, people who prefer a higher thermal comfort level are likely to consume more energy. In this study, we used foresee™, a HEMS developed by the National Renewable Energy Lab (NREL), to perform a sensitivity analysis of occupant preferences with the following objectives: minimize utility cost, minimize carbon footprint, and maximize thermal comfort. To incorporate the preferences into the HEMS, the SMARTER method was used to derive a set of weighting factors for each objective. We performed week-long building energy simulations using a model of a home in Fort Collins, Colorado, where there is mandatory time-of-use electricity rate structure. The foresee™ HEMS was used to control the home with six different sets of occupant preferences. The study shows that occupant preferences can have a significant impact on energy consumption and is important to consider when modeling residential buildings. Results show that the HEMS could achieve energy reduction ranging from 3% to 21%, cost savings ranging from 5% to 24%, and carbon emission reduction ranging from 3% to 21%, while also maintaining a low thermal discomfort level ranging from 0.78 K-hour to 6.47 K-hour in a one-week period during winter. These outcomes quantify the impact of varying occupant preferences and will be useful in controlling the electrical grid and developing HEMS solutions.

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Inter-personal factors affecting building occupants’ thermal tolerance at cold outdoor condition during an autumn–winter period

Indoor and Built Environment ◽

10.1177/1420326x19867999 ◽

2019 ◽

Vol 29 (7) ◽

pp. 987-1005 ◽

Cited By ~ 1

Author(s):

Shahla Ghaffari Jabbari ◽

Aida Maleki ◽

Mohammad Ali Kaynezhad ◽

Bjarne W. Olesen

Keyword(s):

Air Temperature ◽

Indoor Air ◽

Thermal Tolerance ◽

Thermal Sensation ◽

Psychological Adaptation ◽

Balance Model ◽

Winter Period ◽

Personal Factors ◽

Outdoor Temperature ◽

The Impact

The study was conducted to investigate thermal adaptation and the impact of individual differences on developing thermal tolerance when the outdoor temperature falls below 10°C. The applicability of the predicted mean vote (PMV) model was investigated, too. The concept of occupant’s ‘Temperament’ was evaluated as a psychological-adaptation factor. Two main hypotheses were: (a) people with different temperaments would experience different thermal sensations and (b) the classic PMV- predicted percentage dissatisfied (PPD) model is capable of predicting the neutral sensation in heated buildings under cold outdoor temperatures. There was a direct relationship between individual temperament and clothing level as well as thermal sensation. The occupants who were assessed to have cold temperament tend to wear thicker clothes and were more sensitive to variations in indoor air temperature than others. Females with a cold temperament were more than twice as likely to be affected by indoor air temperature as those with a warm temperament. The PMV-PPD model was able to predict the mean neutral temperature in the heated buildings even when the outdoor temperature fell below 10°C. However, when occupants were able to control high indoor temperature, the percentage of true prediction of actual mean votes by the adaptive thermal heat balance model was more than that by the classic PMV model.

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The Significance of Sky Temperature in the Assessment of the Thermal Performance of Buildings

Applied Sciences ◽

10.3390/app10228057 ◽

2020 ◽

Vol 10 (22) ◽

pp. 8057 ◽

Cited By ~ 1

Author(s):

Aiman Albatayneh ◽

Dariusz Alterman ◽

Adrian Page ◽

Behdad Moghtaderi

Keyword(s):

Air Temperature ◽

Thermal Performance ◽

Assessment Tool ◽

Real Data ◽

Building Design ◽

Accurate Estimation ◽

Brick Veneer ◽

Simulation Error ◽

Sky Temperature ◽

The Impact

Energy-efficient building design needs an accurate way to estimate temperature inside the building which facilitates the calculation of heating and cooling energy requirements in order to achieve appropriate thermal comfort for occupants. Sky temperature is an important factor for any building assessment tool which needs to be precisely determined for accurate estimation of the energy requirement. Many building simulation tools have been used to calculate building thermal performance such as Autodesk Computational Fluid Dynamics (CFD) software, which can be used to calculate building internal air temperature but requires sky temperature as a key input factor for the simulation. Real data obtained from real-sized house modules located at University of Newcastle, Australia (southern hemisphere), were used to find the impact of different sky temperatures on the building’s thermal performance using CFD simulation. Various sky temperatures were considered to determine the accurate response which aligns with a real trend of buildings’ internal air temperature. It was found that the internal air temperature in a building keeps either rising or decreasing if higher or lower sky temperature is chosen. This significantly decreases the accuracy of the simulation. It was found that using the right sky temperature values for each module, Cavity Brick Module (CB) Insulated Cavity Brick Module (InsCB), Insulated Brick Veneer Module (InsBV) and Insulated Reverse Brick Veneer Module (InsRBV), will result in 6.5%, 7.1%, 6.2% and 6.4% error correspondingly compared with the real data. These errors mainly refer to the simulation error. On the other hand using higher sky temperatures by +10 °C will significantly increase the simulation error to 16.5%, 17.5%, 17.1% and 16.8% and lower sky temperature by +10 °C will also increase the error to 19.3%, 22.6%, 21.9% and 19.1% for CB, InsCB, InsBV and InsRBV modules, respectively.

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Thermal Performance of Nepalese Building- A Case Study of Dhulikhel and Biratnagar

Journal of the Institute of Engineering ◽

10.3126/jie.v15i3.32012 ◽

2020 ◽

Vol 15 (3) ◽

pp. 73-77

Author(s):

Nischal Chaulagain ◽

Bivek Baral ◽

Saurav Raj Bista

Keyword(s):

Thermal Comfort ◽

Thermal Performance ◽

Research Work ◽

Building Design ◽

Comfort Level ◽

Indoor Climate ◽

Design Code ◽

Electric Equipment ◽

The Government ◽

Real Scenario

Nepal has wide variation in altitude, so does its climate, lifestyle and housing. The building design code issued by the Government of Nepal does not address the issue of thermal comfort, which could be the reason the modern buildings built under the design code are performing poorly in terms of indoor thermal comfort. As a result, people have largely compromised in accommodation. The research includes selection of two representative buildings (at Biratnagar and Dhulikhel) followed by real time monitoring of indoor climate (temperature and Relative humidity). The logged data was used to calibrate the computer model. The model was approximated to real scenario including indoor heat loads from people, lighting, electric equipment and infiltration. Building energy modeling was done in EnergyPlus. The research work depicts the thermal performance of building by comparing the indoor climate of selected buildings of Biratnagar and Dhulikhel with the ASHARE suggested thermal comfort level for humans. The major problem found in the buildings of Biratnagar was overheating for more than 6 months period while for Dhulikhel was under heating for more than 4 months period. The author suggests further research to analyze passive techniques to improve thermal performance and reduce active energy consumption.

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