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.

scholarly journals Optimal Air Conditioner Placement Using a Simple Thermal Environment Analysis Method for Continuous Large Spaces with Predominant Advection

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4663
Author(s):  
Tatsuhiro Yamamoto ◽  
Akihito Ozaki ◽  
Myonghyang Lee
Keyword(s):  
Air Conditioning ◽  
Thermal Environment ◽  
Fluid Dynamic ◽  
Optimal Placement ◽  
Air Conditioner ◽  
Analysis Method ◽  
Computational Fluid Dynamic Analysis ◽  
Environment Analysis ◽  
Air Conditioners ◽  
Energy Simulations

The number of houses with large, continuous spaces has increased recently. With improvements in insulation performance, it has become possible to efficiently air condition such spaces using a single air conditioner. However, the air conditioning efficiency depends on the placement of the air conditioner. The only way to determine the optimal placement of such air conditioners is to conduct an experiment or use computational fluid dynamic analysis. However, because the analysis is performed over a limited period, it is difficult to consider non-stationarity effects without using an energy simulation. Therefore, in this study, energy simulations and computational fluid dynamics analyses were coupled to develop a thermal environment analysis method that considers non-stationarity effects, and various air conditioner arrangements were investigated to demonstrate the applicability of the proposed method. The accuracy verification results generally followed the experimental results. A case study was conducted using the calculated boundary conditions, and the results showed that the placement of two air conditioners in the target experimental house could provide sufficient air conditioning during both winter and summer. Our results suggest that this method can be used to conduct preliminary studies if the necessary data are available during design or if an experimental house is used.

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 KINERJA TERMAL SELUBUNG GEDUNG KULIAH KOTA BANDAR LAMPUNG ITERA

2019 ◽  
Vol 3 (3) ◽  
pp. 267
Author(s):  
Andi Asrul Sani ◽  
Adelia Enjelina Matondang ◽  
Guruh Kristiadi Kurniawan ◽  
Anggi Mardiyanto
Keyword(s):  
Heat Transfer ◽  
Energy Consumption ◽  
Building Energy ◽  
Air Conditioner ◽  
Tropical Country ◽  
Air Conditioners ◽  
Natural Lighting ◽  
Thermal Transfer ◽  
Institute Of Technology ◽  
Window Area

Abstract: The use of glass material should consider the comfort of space in the building. Field of glass is needed as natural lighting and visual facilities between the occupants and the surrounding environment. Its function as natural lighting is often accompanied by an increase in temperature in buildings, considering that Indonesia is a tropical country. Building temperatures that increase due to incoming sunlight can cause discomfort to building occupants. Such conditions make building occupants use air conditioner (AC). The use of air conditioners can increase the value of building energy consumption. For this reason, research on the value of heat transfer in buildings or the value of OTTV (Overall Thermal Transfer Value). OTTV value calculation is done by manual calculation. Bandar Lampung City lecture building at the Sumatra Institute of Technology was chosen as the object of this study. From the results of the study found that the value of heat transfer of a building or OTTV (Overall Thermal Transfer Value) is influenced by the factor of the ratio of the window area to the facade or WWR (Window Wall Ratio) and the shading factor (Shading Coefficient).(Keywords: Keyword: energy consumption, building energy, glass. Abstract: Penggunaan material kaca semestinya mempertimbangkan kenyamanan ruang dalam bangunan. Bidang kaca diperlukan sebagai pencahayaan alami dan sarana visual antara penghuni dan lingkungan sekitar. Fungsinya sebagai pencahayaan alami seringkali disertai dengan peningkatan temperatur pada bangunan, mengingat Indonesia merupakan negara yang beriklim tropis. Temperatur bangunan yang meningkat akibat dari radiasi sinar matahari yang masuk dapat menyebabkan ketidaknyamanan bagi penghuni bangunan. Kondisi seperti itu membuat penghuni bangunan menggunakan air conditioner (AC). Penggunaan air conditioner tersebut dapat meningkatkan nilai konsumsi energi bangunan. Untuk  itu dilakukan penelitian mengenai nilai perpindahan panas dalam bangunan atau nilai OTTV (Overall Thermal Transfer Value). Penghitungan nilai OTTV dilakukan dengan penghitungan manual. Gedung kuliah Kota Bandar Lampung di Institut Teknologi Sumatera di pilih sebagai objek dalam penelitian ini. Dari hasil penelitian ditemukan bahwa nilai perpindahan panas suatu bangunan atau OTTV (Overall Thermal Transfer Value) dipengaruhi oleh faktor nilai perbandingan luas jendela terhadap bidang fasad atau WWR (Window Wall Ratio) dan faktor pembayangan (Shading Coefficient).Kata kunci : konsumsi energi, energi bangunan, kaca.

scholarly journals Impact of Fan Airflow of IT Equipment on Thermal Environment and Energy Consumption of a Data Center

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6166
Author(s):  
Naoki Futawatari ◽  
Yosuke Udagawa ◽  
Taro Mori ◽  
Hirofumi Hayama
Keyword(s):  
Energy Consumption ◽  
Total Energy ◽  
Data Center ◽  
Air Conditioning ◽  
Thermal Environment ◽  
Operating Efficiency ◽  
Inlet Temperature ◽  
Total Energy Consumption ◽  
Air Supply ◽  
Machine Room

Energy-saving in regard to heating, ventilation, and air-conditioning (HVAC) in data centers is strongly required. Therefore, to improve the operating efficiency of the cooling equipment and extend the usage time of the economizer used for cooling information-technology equipment (ITE) in a data center, it is often the case that a high air-supply temperature within the range in which the ITE can be sufficiently cooled is selected. In the meantime, it is known that when the ambient temperature of the ITE rises, the speed of the built-in cooling fan increases. Acceleration of the built-in fan is thought to affect the cooling performance and energy consumption of the data center. Therefore, a method for predicting the temperature of a data center—which simply correlates supply-air temperature with ITE inlet temperature by utilizing existing indicators, such as air-segregation efficiency (ASE)—is proposed in this study. Moreover, a method for optimizing the total energy consumption of a data center is proposed. According to the prediction results obtained under the assumption of certain computer-room air-conditioning (CRAC) conditions, by lowering the ITE inlet temperature from 27 °C to 18 °C, the total energy consumption of the machine room is reduced by about 10%.

scholarly journals Comparison of energy consumption between non-inverter and inverter-type air conditioner in Saudi Arabia

2020 ◽  
Author(s):  
Ahmed Almogbel ◽  
Fahad Alkasmoul ◽  
Zaid Aldawsari ◽  
Jaber Alsulami ◽  
Ahmed Alsuwailem
Keyword(s):  
Saudi Arabia ◽  
Energy Consumption ◽  
Air Conditioning ◽  
High Growth ◽  
Operating Conditions ◽  
Air Conditioner ◽  
Air Conditioners ◽  
Air Conditioning Systems ◽  
Electrical Consumption ◽  
Day By Day

AbstractInterest for air-conditioning systems (ACs) has exponentially expanded worldwide throughout the most recent couple of decades. Countries with booming economies including Saudi Arabia report high growth of sales of room air conditioners. With the expanded (GDP) and warming climates, interest for room air-conditioning systems is required to additionally increment. Meeting the expanded need for electricity energy will be a challenge. Expanded utilization of energy-efficient air conditioners impactsly affects lowering the electricity demand. In an ordinary AC, the blower runs at a fixed speed and is either ON or OFF. In an inverter AC, the compressor is consistently on; however, power drawn relies upon the demand for cooling. The speed of the compressor is adjusted appropriately. In this paper, the energy consumption of non-inverter and an inverter AC of the same capacity was assessed in an average office room, under comparative operating conditions, to find the differences in the energy saving, Carbon Dioxide (CO2) emission, and power consumption of air conditioner. Energy consumption was measured for about 108 days, which is from July 16th to October 31st, 24/7, and compared. The experiment is conducted with the same conditions and same capacity air conditioners (18,000 BTU). Results show that the day-by-day normal vitality utilization, the inverter will save up to 44% of electrical consumption compared to a non-inverter of 3471 kWh/year and 6230 kWh/year respectively. Furthermore, the Total Equivalent Warming Impact (TEWI) analysis shows that inverters can save 49% of CO2 emissions.

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.

Performance Study of the Household Air Conditioner under Extreme Climate Conditions

2013 ◽  
Vol 860-863 ◽  
pp. 1607-1611
Author(s):  
Xin Zhao ◽  
Wei Ting Jiang ◽  
Wei Guo Pan ◽  
Jun Li ◽  
Su Liu ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Cooling Capacity ◽  
Air Conditioner ◽  
Outdoor Temperature ◽  
Performance Study ◽  
Climate Conditions ◽  
Air Conditioners ◽  
Extreme Climate ◽  
Outdoor Climate ◽  
Future Direction

This paper used physical modeling method to simulate the running state of each component of the air conditioner, got the ideal conditions of air conditionor energy consumption model and then calibrated and corrected the model of the air conditioner energy consumption by the experimental data. After utilizing the model for the performance analysis of the actual air conditioner, it was found that the extreme outdoor climate would affect the performance of the air conditioner. In summer, the electricity required to produce the same amount of cooling capacity will be 210% compared with 30°C of outdoor temperature, when the outdoor temperature is 50 °C; In winter, the drop of outdoor temperature will seriously impact on the energy efficiency of air conditioner, when the outdoor temperature is-5°C the electricity required to produce the same amount of cooling capacity will be 150% compared with 10 °C of outdoor temperature. It is of great significance that the results shown in this research contributes to the analysis of air conditioner in extreme conditions, and amended energy consumption of the model can not only forecast the performance of household air conditioners under the extreme climate but also indicate the future direction of air conditionersdesign and improvement.

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 An occupancy-based strategy employing computer vision for reducing cooling energy consumed in buildings

2021 ◽  
Vol 10 (3) ◽  
pp. 1729-1738
Author(s):  
Rania Atef Mohamed AlQadi ◽  
Alaa Zaghloul ◽  
Shereen Aly Taie
Keyword(s):  
Energy Consumption ◽  
Detection Algorithm ◽  
Human Detection ◽  
Air Conditioner ◽  
Air Conditioners ◽  
Proposed Model ◽  
Innovative Model ◽  
Detection Enhancement ◽  
Processing Algorithms ◽  
Two Phases

The energy expended to cool the occupied areas by air conditioners represents a substantial share of the total energy exhausted in buildings. Therefore, developing strategies to reduce this energy is crucial. One of the preponderance strategies adopted to depreciate energy consumption in buildings is the occupancy-based strategy. In this research, an innovative model was established to achieve the goal of reducing cooling energy consumed in buildings based on occupancy-based combined with a constant temperature setpoint strategy in two phases, and each phase engrosses in 20 days. Phase one is to identify the extent of cooling energy employed according to the use of room occupants and its costs in consumption was 276.01 kWh after completion of this phase. Sequentially, constructing phase two intended to reduce cooling energy consumption by employing an automatic air-conditioner (AC) control strategy relying on an improved human detection algorithm with a 25℃ as temperature setpoint, resulting in 112.45 kWh of consumption. To complement the motives for elaboration, the human detection measurement using you only look once (YOLO) improved by applying pre-processing algorithms to reach an average human detection enhancement of 21.2%. The proposed model results showed that potential savings associated with the embraced strategy decreases by more than anticipated as the amount of reduced energy reached 59% savings.

scholarly journals Climate Adaptability of Old and New House in Bushehr's Historical Texture

2020 ◽  
Vol 16 (2) ◽  
pp. 249-258
Author(s):  
Nadiya Mozafari ◽  
Masoud Alimardani
Keyword(s):  
Energy Consumption ◽  
Human Life ◽  
Air Conditioner ◽  
Climate Conditions ◽  
Air Conditioners ◽  
Traditional Design ◽  
Climate Adaptability ◽  
Reduce Energy Consumption ◽  
New Buildings ◽  
Climate Comfort

AbstractThe port of Bushehr, with its valuable and unique historical texture, completely matches with its unbearable climate conditions. Over hundreds of years, the port has provided an appropriate ground for human life as no air conditioner is needed there. Unfortunately, this valuable old texture has been destroyed inadvertently. New buildings in the port are just superficial copies of the old buildings’ external surfaces, with no attention to their goal, i.e., the provision of thermal comfort for inhabitants. The new buildings are dramatically increasing without considering the historical texture and climate. As a result, the inhabitants have to use air conditioners in most months continuously; hence, there would be an increase in energy consumption and a disruption in climate balance. This study has been conducted to compare the compatibility of such architecture with the climate and its success in providing climate comfort for the inhabitants. According to the information obtained from the study, the old houses built more than 100 years ago using traditional design had better performance in adaptability with climate. Accordingly, the exploitation of traditional instructions and patterns in a new format would largely reduce energy consumption in hot seasons and eliminate the need for heating in cold seasons. In this regard, a huge amount of energy is saved, resulting in less damage to the environment.

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