Investigation of the cooling performance and thermal comfort for 4-way cassette air conditioner with swinging motion of vanes

2021 ◽  
Vol 35 (4) ◽  
pp. 1757-1770
Author(s):  
Ho Yeon Choi ◽  
Jae Hyun Oh ◽  
Man Su Park ◽  
Sai Kee Oh ◽  
Yong Gap Park ◽  
...  
2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Yu-Tuan Chou ◽  
Shao-Yi Hsia ◽  
Bi-Wen Lee

Thermal comfort providing is one of the biggest uses of energy in building. For giving better human comfort, the suitable operation conditions of air-conditioner are the most important. The quick and right approach is necessary. In this paper, a small office is studied to improve office staff staying for a long period of time and achieve the thermal comfort environment for reducing energy consumption. Commercial software, Solidworks, is utilized for modeling the facilities and the Flow Simulation module for analyzing the air properties of the indoor space. Four types of air-conditioner operation are applied to set the simulated conditions, including exterior temperature, outlet temperature and wind speed of air-conditioner, and location of air-conditioner. Predicted mean vote (PMV) and predicted percent dissatisfied (PPD) at specific office areas are further acquired through dynamic anthropometry. For seeking the optimal control factors, both of the full factorial method and Taguchi method are utilized to obtain the PMV of specified location. The analyzed result shows the evaluation speed of indoor thermal comfort by Taguchi method is faster than the full-factorial method. It is concluded that software simulation with Taguchi method shows the successful implementation and higher efficiency for thermal comfort assessment.


2020 ◽  
Vol 10 (22) ◽  
pp. 8067
Author(s):  
Tomohiro Mashita ◽  
Tetsuya Kanayama ◽  
Photchara Ratsamee

Air conditioners enable a comfortable environment for people in a variety of scenarios. However, in the case of a room with multiple people, the specific comfort for a particular person is highly dependent on their clothes, metabolism, preference, and so on, and the ideal conditions for each person in a room can conflict with each other. An ideal way to resolve these kinds of conflicts is an intelligent air conditioning system that can independently control air temperature and flow at different areas in a room and then produce thermal comfort for multiple users, which we define as the personal preference of air flow and temperature. In this paper, we propose Personal Atmosphere, a machine learning based method to obtain parameters of air conditioners which generate non-uniform distributions of air temperature and flow in a room. In this method, two dimensional air-temperature and -flow distributions in a room are used as input to a machine learning model. These inputs can be considered a summary of each user’s preference. Then the model outputs a parameter set for air conditioners in a given room. We utilized ResNet-50 as the model and generated a data set of air temperature and flow distributions using computational fluid dynamics (CFD) software. We then conducted evaluations with two rooms that have two and four air conditioners under the ceiling. We then confirmed that the estimated parameters of the air conditioners can generate air temperature and flow distributions close to those required in simulation. We also evaluated the performance of a ResNet-50 with fine tuning. This result shows that its learning time is significantly decreased, but performance is also decreased.


2019 ◽  
Vol 111 ◽  
pp. 01082
Author(s):  
Toshio Yamanaka ◽  
Mari Kuranaga ◽  
Tatsunori Maeda ◽  
Haruto Kitakaze

The authors developed a new radiant air conditioning system named ceiling radiant textile air conditioning system with ceiling cassette unit of packaged air conditioner (PAC). The nonflammable textile is stretched under the ceiling with ceiling cassette units of PAC with a distance of around 30 cm. The aim of this study is to investigate the cooling performance of this new radiant system, so the experiments with full scale model were conducted for three system. The first system is “textile only”, the second system is “textile with guide for air return grille” and the third system is “textile with guide and opening for air return grille”. Airflow rate through textile is measured by tracer gas method. In all cases, the vertical temperature distribution is almost uniform, and the cooling effect of “textile with guide and opening for air return grille” is the largest. As for the radiant effect, two systems of “only textile” and “textile with guide for air return grille” are superior to “textile with guide and opening for air return grille”. The airflow rate trough textile is doubled when using guide, and increased by five times if the opening was provided under the guide.


Author(s):  
Hamza Begdouri ◽  
Luis Rosario ◽  
Muhammad M. Rahman

This study considers airflow simulations to evaluate the impact of different window air-conditioner locations on the thermal comfort in an office rooms (OR). This paper compares the air distribution for an office room by using computational fluid dynamics (CFD) modeling. The air distribution was modeled for a typical office room window air conditioning unit, air supply from a high pressure on the top and the low pressure exhaust on the bottom considering the existing manufacturing ratios for surface areas. Calculations were done for steady-state conditions including an occupant and a light source. The discharge angle for the supply grill of the AC unit was varied from 20 to 40 degrees. The position of the air conditioner was also varied and studied at 60%, 75% and 90% of the total height of the room. In addition the location of the occupant within the office room was varied. Predictions of the air movement, room temperature, room relative humidity, comfort level, and distribution of contaminants within the office room are shown. Analysis of these simulations is discussed. The positions of the air-conditioner unit, the inlet angle and the occupant position in the office room have shown to have important impacts on air quality and thermal comfort. Results are in good agreement with available experimental data.


2011 ◽  
Vol 243-249 ◽  
pp. 4979-4982 ◽  
Author(s):  
Jian Bo Chen ◽  
He Li ◽  
Chao Yang Ji ◽  
Ling Xi

A natural and environment friendly refrigerant propylene (R1270) is proposed as a substitute of R22 in the residential air conditioner. The experiments on the cooling performance of the air conditioner with R1270 and R22 were respectively conducted on an existing enthalpy potential bench, during the degree of superheating keep constant and refrigerant charge directly on the conditioner, also the effect on system performance in the condensing temperature was tested, it is founded that the cooling capacity of R1270 air conditioner was 96% that of R22 air conditioner while the COP of the former increased, and the refrigerant charge amount of R1270 was 56.8 % lower than R22.


2021 ◽  
Vol 881 (1) ◽  
pp. 012016
Author(s):  
R C P Sigalingging

Abstract Global warming is a huge issue and has become a global concern lately. The global warming issue is gaining more attention on reducing fossil energy since fossil energy has significantly exacerbated global warming. Since housing sectors are consuming significant fossil fuel energy, reducing housing energy consumption is necessary. One option discussed in this paper is to reduce the load on the air conditioner (AC) by applying insulation to the building. Reducing the AC energy will reduce the total energy consumption in the buildings. Building practice in a mild climate has shown that good insulation can reduce heating or cooling energy in the building. But using insulation in housing is not a common practice in Indonesia’s construction sectors. Simulating the use of insulation in housing will show how much energy reduction will be obtained, especially for air conditioning energy. The analysis in this study found that thermal comfort is related to air temperature and relative humidity in the room. This article will study the reliability of using insulation in buildings to reduce energy consumption and provide thermal comfort for the occupant.


2019 ◽  
Vol 11 (18) ◽  
pp. 5091 ◽  
Author(s):  
Mun ◽  
Kwak ◽  
Kim ◽  
Huh

In this study a quantitative analysis was performed on the effect on thermal comfort of the stand fan, a personal cooling device that creates local air currents. A total of 20 environmental conditions (indoor temperatures: 22, 24, 26, 28, and 30°C; fan modes: off, low (L) mode, medium (M) mode, and high (H) mode) were analyzed using questionnaires on male and female subjects in their 20s and a thermal manikin test. The contents of the questionnaire consisted of items on thermal sensation, thermal comfort, thermal acceptability, and demands on changes to the air velocity. This step was accompanied by the thermal manikin test to analyze the convective heat transfer coefficient and cooling effect quantitatively by replicating the stand fan. Given that this study provides data on the cooling effect of the stand fan in quantitative values, it allows for a comparison of energy use with other cooling systems such as the air conditioner, and may be used as a primary data set for analysis of energy conservation rates.


Sign in / Sign up

Export Citation Format

Share Document