Numerical Simulation of College Dormitory Ventilation Airflow

2014 ◽  
Vol 522-524 ◽  
pp. 491-494
Author(s):  
Hui Xing Li ◽  
Cheng Cheng Tang ◽  
Guo Hui Feng ◽  
Rui Yang Gao
Keyword(s):  
Indoor Air ◽  
Air Conditioning ◽  
Architectural Design ◽  
Rapid Development ◽  
High Rise ◽  
The North ◽  
Heating And Cooling ◽  
Air Supply ◽  
Central Air Conditioning

China's higher education has entered a rapid development period, the total number of students increased dramatically, using the north-south double-sided architectural design of high-rise dormitory buildings constantly emerge. The indoor air quality of dormitory using central air-conditioning for heating and cooling has become the focus problem. To the north of the dormitory air conditioning as the research object, under the same condition and simulate and analysis the airflow of the side air supply and the top air supply of the air conditioning and ventilation room. The results show that the room adopt the side air supply form has more superiority in comfort and economy.

Conserving Energy by Expanding the Thermal Comfort Envelope

1978 ◽  
Vol 22 (1) ◽  
pp. 533-536 ◽  
Author(s):  
Frederick H. Rohles
Keyword(s):  
Thermal Comfort ◽  
Indoor Air ◽  
Air Conditioning ◽  
Thermal Environment ◽  
Thermal Conditions ◽  
Heating And Cooling ◽  
American Society ◽  
Psychrometric Chart ◽  
Sedentary Activities

Standard 55–74 entitled “Thermal Conditions for Human Occupancy” which is published by The American Society of Heating, Refrigerating, and Air Conditioning Engineers, (ASHRAE) defines an “acceptable thermal environment” as one in which “at least 80 percent of the normally clothed men and women while engaged in indoor sedentary or near sedentary activities would express thermal comfort.” This is pictured on the ASHRAE psychrometric chart as an envelope that includes dry bulb temperatures between 74°F and 77°F at relative humidities between 20% and 60%. The paper will describe five human factors approaches that have been used or are being considered to expand this envelope and thereby conserve energy. These are (1) the use of small radiant heaters which are installed in the modesty panels of desks so comfort may be attained at lower temperatures; (2) the demonstration that night set-back of thermostats to temperatures as low as 50°F do not effect sleeping patterns; (3) the role that interior decor can play in making people feel warmer; (4) the effect that temperature “swings” associated with solar heating and cooling has upon acceptance of the thermal environment and (5) the acceptance of a reduced quality of indoor air as a result of heating with an increased ratio of recirculated air to outside air.

A Study on the Performance of Stratified Air Conditioning Design in Assembly Halls – A Case Study at the Dazhi Cultural Center in Taiwan

2013 ◽  
Vol 368-370 ◽  
pp. 599-602 ◽  
Author(s):  
Ian Hung ◽  
Hsien Te Lin ◽  
Yu Chung Wang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Indoor Air ◽  
Air Conditioning ◽  
Cfd Simulation ◽  
Indoor Temperature ◽  
Cultural Center ◽  
Computational Fluid Dynamics Cfd

This study focuses on the performance of air conditioning design at the Dazhi Cultural Center and uses a computational fluid dynamics (CFD) simulation to discuss the differences in wind velocity and ambient indoor temperature between all-zone air conditioning design and stratified air conditioning design. The results have strong implications for air conditioning design and can improve the indoor air quality of assembly halls.

scholarly journals Can Public Spaces Effectively Be Used as Cleaner Indoor Air Shelters during Extreme Smoke Events?

2021 ◽  
Vol 18 (8) ◽  
pp. 4085
Author(s):  
Amanda J. Wheeler ◽  
Ryan W. Allen ◽  
Kerryn Lawrence ◽  
Christopher T. Roulston ◽  
Jennifer Powell ◽  
...  
Keyword(s):  
Air Quality ◽  
Indoor Air ◽  
Air Conditioning ◽  
High Efficiency ◽  
Public Library ◽  
Public Building ◽  
Central Air Conditioning ◽  
The Media ◽  
The Impact ◽  
Pm2.5 Concentration

During extreme air pollution events, such as bushfires, public health agencies often recommend that vulnerable individuals visit a nearby public building with central air conditioning to reduce their exposure to smoke. However, there is limited evidence that these “cleaner indoor air shelters” reduce exposure or health risks. We quantified the impact of a “cleaner indoor air shelter” in a public library in Port Macquarie, NSW, Australia when concentrations of fine particulate matter (PM2.5) were elevated during a local peat fire and nearby bushfires. Specifically, we evaluated the air quality improvements with central air conditioning only and with the use of portable high efficiency particulate air (HEPA) filter air cleaners. We measured PM2.5 from August 2019 until February 2020 by deploying pairs of low-cost PM2.5 sensors (i) inside the main library, (ii) in a smaller media room inside the library, (iii) outside the library, and (iv) co-located with regulatory monitors located in the town. We operated two HEPA cleaners in the media room from August until October 2019. We quantified the infiltration efficiency of outdoor PM2.5 concentrations, defined as the fraction of the outdoor PM2.5 concentration that penetrates indoors and remains suspended, as well as the additional effect of HEPA cleaners on PM2.5 concentrations. The infiltration efficiency of outdoor PM2.5 into the air-conditioned main library was 30%, meaning that compared to the PM2.5 concentration outdoors, the concentrations of outdoor-generated PM2.5 indoors were reduced by 70%. In the media room, when the HEPA cleaners were operating, PM2.5 concentrations were reduced further with a PM2.5 infiltration efficiency of 17%. A carefully selected air-conditioned public building could be used as a cleaner indoor air shelter during episodes of elevated smoke emissions. Further improvements in indoor air quality within the building can be achieved by operating appropriately sized HEPA cleaners.

scholarly journals Field measurement of PM2.5 concentration in office buildings

2019 ◽  
Vol 111 ◽  
pp. 06064
Author(s):  
Naoki Kagi ◽  
U Yanagi ◽  
Kenichi Azuma ◽  
Hoon Kim
Keyword(s):  
Indoor Air ◽  
Air Conditioning ◽  
Office Buildings ◽  
Central System ◽  
Outdoor Concentration ◽  
Central Air Conditioning ◽  
Building Characteristics ◽  
The Individual ◽  
Pm2.5 Concentration

The characterization of indoor PM2.5 has been concerned about health effects. PM2.5 in indoor air is affected by not only indoor emissions but also penetrations from outdoor air. Therefore, it is important for indoor PM2.5 to take into account of penetration factors of PM2.5 through air conditioning units in buildings. This study aimed at investigating PM2.5 concentrations and I/O ratios (indoor/outdoor concentration) in office buildings. As a result, the relationships between PM2.5 concentrations or I/O ratios and building characteristics could be classified as the types of buildings, such as specific or non-specific, and air conditioning units, such as the individual or central system. The I/O ratio for the specific buildings, over 3,000 m2 of total floor area and buildings that had the central air conditioning unit was relatively low because of medium performance filter in air conditioning units.

Numerical Study on Indoor Air Quality of Commercial Kitchen in China

2011 ◽  
Vol 374-377 ◽  
pp. 1100-1105 ◽  
Author(s):  
Xiao Tan Hou ◽  
An Gui Li ◽  
Zhi Hua Wang ◽  
Yu Jiao Zhao
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Numerical Study ◽  
Average Concentration ◽  
Energy Utilization ◽  
Change Rate ◽  
Air Supply ◽  
Air Change Rate

Indoor air quality of commercial kitchen is investigated and analyzed through velocity, temperature, humidity, and CO2 concentration under different air change rate and supply air temperature. the best air change rate is 30 times per hour and air supply temperature is 301.15K for kitchen, the mean value of the minimum velocity and standard deviation is 0.410m/s and 0.129 respectively, the maximum of the average concentration of CO2 is 659.78ppm, which is less than the acceptance criteria (CO2<1000ppm), and the energy utilization coefficient is maximum of 1.352. Research results show that this air supply mode can optimize indoor air quality.

scholarly journals Design of Central Air Conditioning Control Acquisition Device Based on IoT Technology

2021 ◽  
Vol 2143 (1) ◽  
pp. 012002
Author(s):  
Changwei Huang
Keyword(s):  
Information Integration ◽  
Air Conditioning ◽  
Rapid Development ◽  
Engineering Application ◽  
Mobile Terminal ◽  
Central Air Conditioning ◽  
Acquisition Device ◽  
Intelligent Devices ◽  
System Acquisition ◽  
Conditioning Control

Abstract With the rapid development of Internet and electronic technology, the Internet of things (hereinafter referred to as IOT) has become an important way of many intelligent devices, which can improve people’s application of intelligent devices. Through the IOT, we can carry out the research on the centralized monitoring system of central air conditioning [1]. Through the IOT, we can realize the IOT of indoor and outdoor units of central air conditioning, which can realize the important application of practical engineering projects. Through fuzzy algorithm, this paper can improve the overall improvement of the project. Through the cooperation of MCU and GPRS module, we can complete the wireless transmission of data., This can realize computer terminal monitoring and mobile terminal monitoring. Through engineering application, we can realize the automation and information integration of system monitoring, which will greatly improve the monitoring efficiency. Through the development of acquisition device, we can improve the comfort and security of central air conditioning, which will enhance the communication between the physical equipment of the system and the upper server network. Firstly, this paper analyzes the flow of fuzzy PID algorithm. Then, this paper specifies the system diagram of the central air conditioning control acquisition system [2]. Finally, this paper puts forward the important work of system acquisition.

scholarly journals Centralized on-line monitoring system for pipeline and cable environment and fresh air of air conditioning

2021 ◽  
Vol 2087 (1) ◽  
pp. 012039
Author(s):  
Zhihua Ye ◽  
Yudong Xu ◽  
Xinchao Bao ◽  
Zhenghao Li ◽  
Wei Zhang
Keyword(s):  
Monitoring System ◽  
Air Conditioning ◽  
System Structure ◽  
Operation Process ◽  
Central Air Conditioning ◽  
On Line ◽  
Online Monitoring System ◽  
Monitoring Quality ◽  
Structure Configuration

Abstract Aiming at the problem of on-line centralized monitoring error of pipeline and cable environment and fresh air of air conditioning, a utility model is designed, a centralized monitoring system of pipeline and cable environment and fresh air of air conditioning is disclosed, the system structure configuration is optimized, and the system performance is improved by combining multiple central air conditioning controllers, data processors, acquisition servers and other equipment, combined with LabVIEW technology, the system software function and operation process are improved. Finally, the experiment proves that the centralized online monitoring system for pipeline and cable environment and air conditioning fresh air can better reduce the monitoring error and ensure the real-time monitoring quality of pipeline and cable environment and air conditioning fresh air.

Recent Patents on OPC for Central Air-Conditioning System

2014 ◽  
Vol 8 (1) ◽  
pp. 234-239
Author(s):  
Jiejia Li ◽  
Peng Yang ◽  
Xiaoyan Han ◽  
Pengcheng Guo
Keyword(s):  
Air Conditioning ◽  
Integrated Management ◽  
Rapid Development ◽  
Data Communications ◽  
Air Conditioning System ◽  
Opc Server ◽  
Opc Client ◽  
Opc Technology ◽  
Central Air Conditioning ◽  
And Control

To achieve the centralized monitoring and integrated management of the central air-conditioning system, taking the characteristics of data communications and control complexity in the air-conditioning system into consideration, and combined with the OPC (OLE(Object Linking and Embedding) for Process Control) technology, an intelligent central airconditioning supervisory system is developed and designed. In this paper, after searching the OPC technology standard, the overall structure diagram of the monitoring system is designed, and the OPC server program is also developed by using Knight OPC Server Rapid Development Toolkits. The OPC client application program and man-machine interface are exploited by KingView configuration software. The monitor and control system whose interface is opened is designed for the central air-conditioning. In the end, the experiment result proves that the system operation has good performance for temperature-controller and humidity-controller clustered controlling as well as data communications, thus, satisfying the requirements.

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