scholarly journals Performance and environmental effects of refrigerants used in the rooftop air-conditioning of building for carbon emission: A case of theoretical and numerical modelling

Author(s):  
Kaan Suerdem ◽  
Tolga Taner ◽  
Ozgen Acikgoz ◽  
Ahmet Selim Dalkilic ◽  
Somchai Wongwises

Abstract This study analyzes six different refrigerants with different characteristics using the same rooftop air conditioner considering the environmental effects unlike other studies. All evaluations are drafted in two different scenarios, thanks to the equal refrigerant charge amount and equal energy consumption to make the performance review more accurate. Cooling capacity, energy consumption, temperature and pressure values are obtained through a numerical simulation program so as to obtain performance values. In order to prove the accuracy of the values obtained from the simulation program, the rooftop air conditioner using R410A refrigerant is tested in the laboratory environment. The Life Cycle Climate Performance method is used for environmental analyses to calculate the carbon emissions of six different refrigerants in two different scenarios. These experimental tests are carried out at outdoor temperatures of 20ºC, 25ºC, 30ºC and 35ºC. The maximum difference in cooling capacity, energy consumption and energy efficiency is determined as 2.8% between simulation and experimental outputs. According to the results from and equal refrigerant charged and equal energy consumption scenarios, R410A, R454B and R32 refrigerants are found to have better cooling capacities than other refrigerants in performance analyses.

2013 ◽  
Vol 860-863 ◽  
pp. 1607-1611
Author(s):  
Xin Zhao ◽  
Wei Ting Jiang ◽  
Wei Guo Pan ◽  
Jun Li ◽  
Su Liu ◽  
...  

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.


2012 ◽  
Vol 20 (1) ◽  
pp. 35-40
Author(s):  
S. Štefunková

Characteristics of asphalt mixes with FT additiveThis article is focused on low-temperature asphalt mixture technologies using FT additive and RAP. The modern production and use of asphalt mixture technologies with reduced temperatures has many advantages. These advantages mainly help to save energy and the environment. Lower temperatures enable a reduction in energy consumption, a more acceptable working environment for workers, a reduction in negative environmental effects, such as greenhouse gas emissions, and an improvement in the workability of mixtures and a prolongation of their duration. This technology is currently becoming popular in many countries.


2019 ◽  
Vol 3 (3) ◽  
pp. 267
Author(s):  
Andi Asrul Sani ◽  
Adelia Enjelina Matondang ◽  
Guruh Kristiadi Kurniawan ◽  
Anggi Mardiyanto

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.


With the aim of saving energy and to reduce global warming effect, our work focuses on the valorization of the waste heat evacuated by the condenser of a refrigeration machine (air-conditioner) for the desalination of sea water. In this paper, the conception of a new system combining airconditioning and desalination is realized. The modelling of the heat exchanges of each part of the system is realized. To improve the performance of the system, various experimental tests are represented and discussed. Comparison between simulation and experimental results shows a good agreement and present a courageous motive for the system application.


2018 ◽  
Vol 67 ◽  
pp. 02055
Author(s):  
Gandjar Kiswanto ◽  
Maulana Azmi ◽  
Ignatia Averina

Micro milling is currently being used to make micro-sized products, such as in MEMS, medical devices, etc. But in the process of machining, especially in roughing process, micro milling spends a lot of energy that can still be reduced to contribute to green manufacturing. This study focuses on developing the model of energy consumption during the micro milling processes. The model is then used to map the energy consumption from different cutting toolpaths and strategies. Furthermore this study also comparing and characterizing the energy consumed between macro milling and micro milling of the same part shape but with significant different in size. In conclusion, this study shows different characteristics and comparison in energy consumption between micro milling and macro milling.


2015 ◽  
Vol 56 (2) ◽  
pp. 130-136
Author(s):  
Yoshiki MIYAZAKI ◽  
Koichiro WAKI ◽  
Katsutoshi MIZUNO ◽  
Kazuya IKEDA

2018 ◽  
Vol 225 ◽  
pp. 02013
Author(s):  
Mohd Hazwan Yusof ◽  
Sulaiman Mohd Muslim ◽  
Muhammad Fadhli Suhaimi ◽  
Mohamad Firdaus Basrawi

To maintain the temperature setup on an air conditioner, the compressor will use more or less energy based on the outdoor temperature. Therefore, there is a need to understand the performance of the air conditioner if the outdoor temperature is varied. In this research, a used small capacity split-unit air conditioner using R-22 refrigerant is used to study the effect of outdoor temperature on the performance of the air conditioner. From the results, it can be understood that lower outdoor temperature requires less work from the compressor. The cooling capacity and coefficient of performance drop as the outdoor temperature increases.


2019 ◽  
Vol 111 ◽  
pp. 06035
Author(s):  
Sihwan Lee

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.


2013 ◽  
Vol 827 ◽  
pp. 298-301
Author(s):  
Jian Zhang

The direct evaporative cooling conditioner experimental research is carried out in this paper. Analyze the influence of inlet air dry ball temperature and relative humidity to air conditioner cooling capacity and cooling efficiency, which has certain guiding significance to improve the direct evaporative cooling air conditioner performance.


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