Effect of Indoor Thermal Environment on Building Energy Consumption

2012 ◽  
Vol 193-194 ◽  
pp. 137-141
Author(s):  
Kun Cai ◽  
Zheng Dong Chen ◽  
Xue Bin Yang ◽  
Yao Fen Zhang ◽  
Ming Xue Li
Keyword(s):  
Energy Consumption ◽  
Indoor Air ◽  
Thermal Environment ◽  
Building Energy ◽  
Indoor Environments ◽  
Air Velocity ◽  
Point Temperature ◽  
Set Point ◽  
Thermal Environments ◽  
Neutral Temperature

This study reviews some published literatures to seek the relationship between the parameters of indoor environments and the energy consumption. The indoor thermal environments are categorized and defined as different indices and variables. The building energy can be determined by indoor air temperature, occupant-area ratio and working days. Several parameters of indoor thermal environments such as air velocity, neutral temperature, predicted mean vote, indoor air quality, and set point temperature, are summarized for their influence on the energy consumption. It can be concluded that the increased local air velocity, enhanced neutral temperature, and enlarged set point temperature may be beneficial to reduce the energy consumption.

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

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.

scholarly journals Analysis of the Influence Subjective Human Parameters in the Calculation of Thermal Comfort and Energy Consumption of Buildings

Energies ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1531 ◽  
Author(s):  
Roberto Robledo-Fava ◽  
Mónica C. Hernández-Luna ◽  
Pedro Fernández-de-Córdoba ◽  
Humberto Michinel ◽  
Sonia Zaragoza ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Energy Consumption ◽  
Monte Carlo Method ◽  
Numerical Model ◽  
Thermal Comfort ◽  
Energy Demand ◽  
Measured Data ◽  
Point Temperature ◽  
Set Point ◽  
Indoor Comfort

In the present work, we analyze the influence of the designer’s choice of values for the human metabolic index (met) and insulation by clothing (clo) that can be selected within the ISO 7730 for the calculation of the energy demand of buildings. To this aim, we first numerically modeled, using TRNSYS, two buildings in different countries and climatologies. Then, we consistently validated our simulations by predicting indoor temperatures and comparing them with measured data. After that, the energy demand of both buildings was obtained. Subsequently, the variability of the set-point temperature concerning the choice of clo and met, within limits prescribed in ISO 7730, was analyzed using a Monte Carlo method. This variability of the interior comfort conditions has been finally used in the numerical model previously validated, to calculate the changes in the energy demand of the two buildings. Therefore, this work demonstrated that the diversity of possibilities offered by ISO 7730 for the choice of clo and met results, depending on the values chosen by the designer, in significant differences in indoor comfort conditions, leading to non-negligible changes in the calculations of energy consumption, especially in the case of big buildings.

scholarly journals Study on energy loss and thermal environment through door open while air conditioner running

2019 ◽  
Vol 111 ◽  
pp. 06035
Author(s):  
Sihwan Lee
Keyword(s):  
Energy Consumption ◽  
Indoor Air ◽  
Room Temperature ◽  
Thermal Environment ◽  
Infiltration Rate ◽  
Operating Efficiency ◽  
Air Conditioner ◽  
Air Conditioners ◽  
Cooling Period ◽  
Closed State

While air conditioner is running, opening doors and windows is a great way to reduce operating efficiency and undermine the air conditioning system’s ability to bring the indoor to a comfortable temperature. The purpose of this study is to evaluate the heat loss and thermal environment through the door open while air conditioner running. To achieve this goal, using full-scale measurement with the commercial store during the cooling period, the infiltration rate, thermal environment and energy consumption of air conditioners with door opened and door closed state were measured. The measured results show that the infiltration rate at the door opened state was increased by about 21.3 times compared to the door closed state. When the set temperature of the air conditioner was 24 °C, the room temperature in the opening gate cooling was measured to be about 5 °C higher than the closing gate cooling. However, the energy consumption was measured approximately 12 kWh/day and there was no difference with door state. This means that the energy consumption is not increased if the indoor air temperature would not reach the set point temperature of air conditioner.

Thermal comfort analyses of naturally ventilated university classrooms

2016 ◽  
Vol 34 (4/5) ◽  
pp. 427-445 ◽  
Author(s):  
Baharuddin Hamzah ◽  
Muhammad Taufik Ishak ◽  
Syarif Beddu ◽  
Mohammad Yoenus Osman
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
National Standard ◽  
Content Type ◽  
Thermal Environments ◽  
Neutral Temperature ◽  
Radiant Temperature ◽  
University Classrooms

Purpose The purpose of this paper is to analyse thermal comfort and the thermal environment in naturally ventilated classrooms. Specifically, the aims of the study were to identify the thermal environment and thermal comfort of respondents in naturally ventilated university classrooms and compare them with the ASHRAE and Indonesian National Standard (SNI); to check on whether the predicted mean vote (PMV) model is applicable or not for predicting the thermal comfort of occupants in naturally ventilated university classrooms; and to analyse the neutral temperature of occupants in the naturally ventilated university classrooms. Design/methodology/approach The study was carried out at the new campus of Faculty of Engineering, Hasanuddin University, Gowa campus. A number of field surveys, which measured thermal environments, namely, air temperature, mean radiant temperature (MRT), relative humidity, and air velocity, were carried out. The personal activity and clothing properties were also recorded. At the same time, respondents were asked to fill a questionnaire to obtain their thermal sensation votes (TSV) and thermal comfort votes (TCV), thermal preference, and thermal acceptance. A total of 118 respondents participated in the study. Before the survey was conducted, a brief explanation was provided to the participants to ensure that they understood the study objectives and also how to fill in the questionnaires. Findings The results indicated that the surveyed classrooms had higher thermal environments than those specified in the well-known ASHRAE standard and Indonesian National Standard (SNI). However, this condition did not make respondents feel uncomfortable because a large proportion of respondents voted within the comfort zone (+1, 0, and −1). The predictive mean vote using the PMV model was higher than the respondents’ votes either by TSV or by TCV. There was a huge difference between neutral temperature using operative temperature (To) and air temperature (Ta). This difference may have been because of the small value of MRT recorded in the measured classrooms. Originality/value The research shows that the use of the PMV model in predicting thermal comfort in the tropic region might be misleading. This is because PMV mostly overestimates the TSV and TCV of the respondents. People in the tropic region are more tolerant to a higher temperature. On the basis of this finding, there is a need to develop a new thermal comfort model for university classrooms that is particularly optimal for this tropical area.

scholarly journals Quantification of indoor environments and study of thermal comfort in naturally hostel buildings in the tropical country, India

2019 ◽  
Vol 111 ◽  
pp. 02059
Author(s):  
Sanjay Kumar ◽  
Manoj Kumar Singh ◽  
Varun Kumar Gupta
Keyword(s):  
Thermal Comfort ◽  
Thermal Environment ◽  
Monsoon Season ◽  
Weather Conditions ◽  
Good Health ◽  
Learning Performance ◽  
Indoor Environments ◽  
Tropical Country ◽  
Thermal Environments ◽  
Adaptive Action

Hostel buildings prime objective is to provide better thermal environments to the students for their good health and learning performance. In India, a very few studies are done on the thermal environments of multi-storied naturally ventilated hostel buildings. We carried out a thermal comfort study in two mid-rise (~G+5 floors) naturally ventilated (NV) hostel buildings during monsoon season (August-September, 2018). The field study conducted for three consecutive weeks collecting 642 valid subjective responses with objective information regarding thermal parameters of 253 rooms. Statistical analysis of student’s responses and measured thermal environment variables was performed for assessing inter buildings effects, different weather conditions (rainy or cloudy) and daytime duration (morning, afternoon and evening), respectively. The study finds the mean thermal neutrality at 29.9°C for the studied group using Griffiths’ method. The results suggested that more than 80% of subjects were voting within central three categories when indoor operative temperature ranged between 28-32.1°C. The primary adaptive action of occupants includes switching on the fans (100%) followed by the opening of external doors (80%) and opening or closing of windows (55%) to restore thermal comfort in built environments.

Energy Consumption Simulation for Residential Buildings With Shading Devices in Different Regions

2007 ◽  
Author(s):  
Junjie Liu ◽  
Xiaojie Zhou ◽  
Zhihong Gao
Keyword(s):  
Energy Consumption ◽  
Residential Buildings ◽  
Residential Building ◽  
Building Energy ◽  
Energy Performance ◽  
Indoor Environments ◽  
Total Energy Consumption ◽  
South West ◽  
Shading Devices ◽  
Energy Consumption Simulation

With the development of energy saving, it is needed to calculate the energy consumption of the residential building, particularly accurate dynamic energy consumption. Fixed shading devices are wildly used to save building energy because they prevent undesirable heat coming through the windows during the “overheated period”, just as in summer, which can ameliorate the indoor environments and reduce the energy consumption of air-conditioning in summer. But they will also prevent solar energy which can be used in winter to enter windows. So it is very important to be able to determine the optimal shading devices of windows. The overhangs and vertical-shading devices are representative to study the different energy performance in summer and winter, in an actual dwell house. On the other hand, fixed shading devices can weaken the effect of daylighting, so we would take both the total energy consumption and rooms’ daylighting into account. In this study, we choose several typical dwelling houses in different cities located in north, south, west, east and central region of China respectively. We calculated energy consumption of those models by using Energyplus program, and compared the shading performance of horizontal and vertical shading devices, then optimal configuration dimensions of horizontal shading devices are recommended on the basis of different requirements for solar heat gains in winter and in summer for those typical dwelling houses.

Indoor Thermal Environments Investigation in Winter of Rural Houses in Yinchuan

2012 ◽  
Vol 209-211 ◽  
pp. 289-293 ◽  
Author(s):  
Quan He ◽  
Da Long Liu ◽  
Qun Zhang
Keyword(s):  
Energy Consumption ◽  
Thermal Environment ◽  
Thermal Environments ◽  
New Type ◽  
High Insulation ◽  
Heating Energy Consumption ◽  
Heating Mode ◽  
Straw Bale ◽  
Insulation Performance ◽  
Partial Interval

The main considerations of building some new-type rural houses in Yinchuan are to improve indoor thermal environment and to reduce heating energy consumption by passive solar use and high-insulation envelope. Two houses were measured, a traditional one with adobe walls and a wooden roof, and a newly-built one with straw-bale insulation. Results show: (1) the linear layout of the traditional house leads to a higher heating energy consumption than the new one with climatic buffers; (2) the new house with straw-bale bricks have better thermal insulation performance than the traditional one with adobe wall; (3) lacking thermal storage is one of the main causes of larger indoor temperature fluctuation in the new house; (4) as a traditional partial interval heating mode, the “Kang”(a bed-stove made of bricks or fired clay) in the bedroom uses energy efficiently and improves the indoor thermal comfort.

Typical effects of occupants’ behaviour on indoor air-conditioned environments in the hot summer and cold winter region of China

2020 ◽  
pp. 1420326X1990064
Author(s):  
Biao Yan ◽  
Xi Meng ◽  
Jinlong Ouyang ◽  
Enshen Long
Keyword(s):  
Energy Consumption ◽  
Indoor Air ◽  
Thermal Environment ◽  
Heating Temperature ◽  
Characteristic Temperature ◽  
Indoor Temperature ◽  
Indoor Thermal Environment ◽  
Door Opening ◽  
Survey Results ◽  
The Relationship

This paper examines the effects of occupants’ behaviour on the thermal environment in air-conditioned rooms. Typical occupants’ behaviours were determined from survey results in the hot summers and cold winters region of China. The temperature setpoint, intermittent operation and door opening were determined as influencing factors in a theoretical model for maintaining thermal comfort with minimal energy consumption. The concepts of the temperature change index and characteristic temperature were introduced to predict the relationship between the indoor thermal environment and occupants’ behaviour. The model was validated with empirical experiments and numerical simulations. The results indicated that continuous opening of doors and windows in air-conditioned rooms would increase the energy consumption that is needed to maintain a desirable indoor thermal environment. The average indoor temperature at 25°C setpoint heating temperature with the door open at 90° was found equal to the average indoor setpoint temperature of 22°C with the door open at 45°. The relative effects of the tested occupants’ behaviours were also evaluated.

scholarly journals Research on the Impact of Wind Angles on the Residential Building Energy Consumption

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Zou Huifen ◽  
Yang Fuhua ◽  
Zhang Qian
Keyword(s):  
Energy Consumption ◽  
Heat Loss ◽  
Indoor Air ◽  
Wind Direction ◽  
Natural Ventilation ◽  
Building Energy ◽  
Simulation Software ◽  
Outdoor Environment ◽  
Building Energy Consumption ◽  
The Impact

Wind angles affect building’s natural ventilation and also energy consumption of the building. In winter, the wind direction in the outdoor environment will affect heat loss of the building, while in summer the change of wind direction and speed in the outdoor environment will affect the building’s ventilation and indoor air circulation. So, making a good deal with the issue of the angle between local buildings and the dominant wind direction can effectively solve the winter and summer ventilation problems. Thereby, it can enhance the comfort of residential person, improve indoor air quality, solve heat gain and heat loss problems in winter and summer in the severely cold and cold regions, and reduce building energy consumption. The simulation software CFD and energy simulation software are used in the paper. South direction of the building is the prototype of the simulation. The angle between the direction of the building and the outdoor environment wind is changed sequentially. Energy consumption under different wind angle conditions is compared with each other. Combined with natural ventilation under various wind angles, the paper gives the best recommended solution of building direction in Shenyang.

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