scholarly journals Applicability of the whole-house air conditioning system in cold climate district

2019 ◽  
Vol 111 ◽  
pp. 06036
Author(s):  
Sihwan LEE ◽  
Takuya KISHI ◽  
Yoshiharu ASANO
Keyword(s):  
Heat Shock ◽  
Temperature Difference ◽  
Air Conditioning ◽  
Room Temperature ◽  
Thermal Environment ◽  
Residential Buildings ◽  
Cold Climate ◽  
Airflow Rate ◽  
Air Conditioning System ◽  
The Individual

The number of sudden deaths while bathing related to heat shock in Japan is approximately 17,000 people for a year. This number is over 30% of elderly people dying in the residential buildings. To solve this problem, it is effective to introduce a whole-house air conditioning system in the residential buildings. The purpose of this study is to evaluate the applicability of the whole-house air conditioning system in cold climate district in Japan. To achieve this goal, this study is evaluated the thermal environment by using the whole-house air conditioning system and compared with individual air conditioning system. The results show that the maximum room temperature difference is measured approximately 6.8 ºC. As the reverse simulation in the study, this temperature difference can be decreased to approximately 4 ºC by adjusting the supply airflow rate. When the individual air conditioning is used, the room temperature difference is 7.5 ºC. It means that using the whole-house air conditioning system decreases the room temperature difference and reduces heat shock risk. It is also possible to raise the surface temperature of the wall by 20 to 30 % than in case of using individual air conditioning, thus it is effective in preventing dew condensation on the wall surface.

scholarly journals Research on Heat Transfer Performance of Micro-Channel Backplane Heat Pipe Air Conditioning System in Data Center

2020 ◽  
Vol 10 (2) ◽  
pp. 583
Author(s):  
Liping Zeng ◽  
Xing Liu ◽  
Quan Zhang ◽  
Jun Yi ◽  
Xianglong Liu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchange ◽  
Heat Pipe ◽  
Temperature Difference ◽  
Air Conditioning ◽  
Heat Transfer Performance ◽  
Transfer Performance ◽  
Micro Channel ◽  
Filling Rate ◽  
Air Conditioning System

This paper deals with the heat transfer performance of a micro-channel backplane heat pipe air conditioning system. The optimal range of the filling rate of a micro-channel backplane heat pipe air conditioning system was determined in the range of 65–75%, almost free from the interference of working conditions. Then, the influence of temperature and air volume flow rate on the heat exchange system were studied. The system maximum heat exchange is 7000–8000 W, and the temperature difference between the inlet and outlet of the evaporator and the condenser is almost 0 °C. Under the optimum refrigerant filling rate, the heat transfer of the micro-channel heat pipe backplane system is approximately linear with the temperature difference between the inlet air temperature of the evaporator and the cooling distribution unit (CDU) inlet water temperature in the range of 18–28 °C. The last part compares the heat transfer characteristics of two refrigerants at different filling rates. The heat transfer, pressure, and refrigerant temperature of R134a and R22 are the same with the change of filling rate, but the heat transfer of R134a is lower than that of R22. The results are of great significance for the operational control and practical application of a backplane heat pipe system.

scholarly journals Cooling performance of Ceiling Radiant Textile Air Conditioning System with Ceiling Cassette Unit of Packaged Air Conditioner

2019 ◽  
Vol 111 ◽  
pp. 01082
Author(s):  
Toshio Yamanaka ◽  
Mari Kuranaga ◽  
Tatsunori Maeda ◽  
Haruto Kitakaze
Keyword(s):  
Air Conditioning ◽  
Scale Model ◽  
Airflow Rate ◽  
Air Conditioner ◽  
Tracer Gas ◽  
Vertical Temperature ◽  
Air Conditioning System ◽  
Cooling Performance ◽  
The Third ◽  
Vertical Temperature Distribution

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.

Numerical and experimental investigation on the air flow characteristics of heating, ventilation, and air-conditioning module for a small electric vehicle

2019 ◽  
Vol 234 (6) ◽  
pp. 1597-1609
Author(s):  
Kang Li ◽  
Hao Gao ◽  
Peng Jia ◽  
Lin Su ◽  
Yidong Fang ◽  
...  
Keyword(s):  
Heat Pump ◽  
Flow Rate ◽  
Air Conditioning ◽  
Air Flow ◽  
Flow Characteristics ◽  
Cold Climate ◽  
Airflow Rate ◽  
Positive Temperature ◽  
Air Flow Rate ◽  
Pump System

In electrical vehicles, replacing positive temperature coefficient heater as heat source with an air source heat pump could improve the driving range and decrease energy consumption in cold climate. Design of the heating, ventilation, and air-conditioning module for heat pump system has a significant influence on its performance in each working mode. A newly designed heat pump heating, ventilation, and air-conditioning module was introduced in this paper. The air flow characteristics of the heat pump heating, ventilation, and air-conditioning module in four working modes were analyzed, and the air flow rate and wind resistance were obtained by numerical simulation. Experiments were also conducted for validating its airflow rate in each working mode. Results of these experiments show that some unfavorable phenomena such as flow maldistribution and vortex inside the heat pump heating, ventilation, and air-conditioning module exist, which could lead to insufficient utilization of the heat exchange area of heat exchangers and the generation of aerodynamic noise. Furthermore, the air flow rate of the original heating, ventilation, and air-conditioning module was also measured for comparison, and the designed heat pump heating, ventilation, and air-conditioning module shows nearly 15–20% decrease in each working mode.

scholarly journals Simulation and experimental study of phase change cooling and heating wall radiation air conditioning system

2020 ◽  
Vol 143 ◽  
pp. 02044
Author(s):  
Gao Chunxue ◽  
Wu Songlin ◽  
Lang Junqian ◽  
Liu Qiuxin
Keyword(s):  
Phase Change ◽  
Thermal Performance ◽  
Air Conditioning ◽  
Field Experiments ◽  
Thermal Environment ◽  
Operating Conditions ◽  
Operation Condition ◽  
Heating Wall ◽  
Air Conditioning System ◽  
Winter Operation

This paper presents a case study of phase change cooling and heating wall radiant (PC-CHWR) air conditioning system application in an energy-saving renovation project in a laboratory in Wuhan, Hubei province in China. To test the thermal performance of the system, the PHOENICS software was utilized to simulate and analyse the indoor thermal environment in the laboratory under both winter and summer operating conditions. In addition, field experiments were also conducted under winter operation condition. By comparing the results between numerical simulation and field experiment, it is found that thermal performance of the PC-CHWR air conditioning system evaluated by these two evaluation methods are quite match. Moreover, the results also show that the PC-CHWR system can meet the cooling and heating load of the building within the acceptable range.

scholarly journals Evaluation of Thermal Behavior of the Skeleton in a Green Building with the Aid of TABS

2019 ◽  
Vol 111 ◽  
pp. 01085
Author(s):  
Hiroshi Muramatsu ◽  
Tatsuo Nobe
Keyword(s):  
Heat Flux ◽  
Thermal Behavior ◽  
Air Conditioning ◽  
Natural Ventilation ◽  
Thermal Environment ◽  
Concrete Slab ◽  
Ventilation System ◽  
Office Building ◽  
Air Conditioning System ◽  
Indoor Thermal Environment

In this study, an office building in Japan that incorporates energy-saving features and environmental technologies was investigated. This office building features a green façade, natural ventilation, a concrete slab with no suspended ceilings, and thermo-active building systems. Two airconditioning systems were installed in this building—a ceiling radiation air-conditioning system and a whole floor-blow off air conditioning system. In addition, a natural ventilation system was installed. We surveyed the heat flux of the ceiling surface and indoor thermal environment of this building from 2015 through 2016. The ceiling using the heat storage amount of concrete maintains a constant temperature in the workplace during as well as after office hours. We also performed detailed measurements of the heat flux of the ceiling surface and indoor thermal environment in the summer of 2017. The results showed that the ceiling radiation air-conditioning system provided a stable thermal environment. Furthermore, we report that making use of the thermal behavior of the skeleton improved the operation of the ceiling radiation airconditioning system.

Climatic Strategies of Indoor Thermal Environment for Residential Buildings in Yangtze River Region, China

2011 ◽  
Vol 20 (1) ◽  
pp. 101-111 ◽  
Author(s):  
Baizhan Li ◽  
Wei Yu ◽  
Meng Liu ◽  
Nan Li
Keyword(s):  
Energy Efficiency ◽  
Thermal Comfort ◽  
Yangtze River ◽  
Air Conditioning ◽  
Natural Ventilation ◽  
Thermal Environment ◽  
Residential Buildings ◽  
Design Strategies ◽  
River Region ◽  
Climatic Adaptability

Yangtze River Valley is situated within the Hot Summer and Cold Winter zone, and residents in this region of China would require HVAC system to alleviate thermal comfort conditions, although this is tempered by the Design Code (DBJ50-071-2007) for energy efficiency. A 1-year survey of about 200 residential homes was carried out in eight cities covering the breadth of the region. The acceptable temperature range for the residents in this area was 16.3—28.1°C and the thermal neutral temperature was found to be 27.6°C in summers and 17.5°C in winters. People in different area can vary in their adaptability and comfortableness. Therefore, there is a need to investigate the national comfort parameter introduced in the Code for Design of Heating and Ventilation and Air Conditioning (GB50019-2003). The results found that if air-conditioning system was set to 27.5°C instead of 26°C as required by GBJ19-87: Design Standard of Heating and Ventilation and Air Conditioning, a 16.5% saving of energy consumption could be achieved. The findings demonstrated the role of natural ventilation in the expansion of the thermal comfort zone for the residents, especially during the summer seasons. A climatic adaptability model has been established by this study to contribute to the passive climatic design strategies for a better economic and energy efficiency of buildings.

Sign in / Sign up

Export Citation Format

Share Document