The simulation and calculation of indoor thermal environment and the PPD evaluation index affected by three typical air-conditioning supply modes

2014 ◽  
Vol 20 (3) ◽  
pp. 344-350 ◽  
Author(s):  
Zeqin Liu ◽  
Ge Li ◽  
Chenxiao Zheng
Keyword(s):  
Air Conditioning ◽  
Thermal Environment ◽  
Evaluation Index ◽  
Indoor Thermal Environment

Quantitative investigations on setting parameters of air conditioning (air-supply speed and temperature) in ventilated cooling rooms

2019 ◽  
Vol 30 (1) ◽  
pp. 99-113 ◽  
Author(s):  
Haofu Chen ◽  
Zhuangbo Feng ◽  
Shi-Jie Cao
Keyword(s):  
Thermal Comfort ◽  
Air Conditioning ◽  
Thermal Environment ◽  
Inertial Force ◽  
Index Formula ◽  
Design Parameters ◽  
Dimensionless Number ◽  
Indoor Thermal Environment ◽  
Indoor Thermal Comfort ◽  
Air Supply

Rational and scientific design of indoor air conditioning is essential. In the design of Heating, Ventilating and Air Conditioning system, air-supply speed (ventilation rate) and air-supply temperature are the two most important parameters. In the current study, numerical simulations and experimental measurements were adopted to investigate the influences of ventilation mode, air-supply velocity and air-supply temperature on indoor thermal comfort as well as building energy consumption in summer. Different ventilation modes (up supply and down exit, ceiling supply and ceiling exit) were considered in modelling. Based on the simulation and experimental results, dimensionless index [Formula: see text] is proposed, which represents the ratio of buoyancy weighting force to inertial force. This index can be used as a pre-evaluation index of indoor thermal comfort in preliminary design of air conditioning. It is an indicator to judge the working conditions in cooling-ventilated rooms. When [Formula: see text], the settlement and diffusion effects of indoor airflow reach a good level, which means that the parameter setting could provide a comfortable indoor thermal environment. The dimensionless number [Formula: see text] is a theoretically based tool in the pre-evaluation of indoor thermal environment, providing guidance for setting of ventilation design parameters.

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.

scholarly journals Human-Oriented Design of an Indoor Thermal Environment

2019 ◽  
Vol 111 ◽  
pp. 02001
Author(s):  
Masanari Ukai ◽  
Tatsuo Nobe
Keyword(s):  
Air Conditioning ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Hot Spot ◽  
Clothing Insulation ◽  
Air Conditioning System ◽  
Indoor Thermal Environment ◽  
Initial Survey ◽  
Air Conditioning Systems ◽  
Temperature Side

In this study, an initial survey of clothing insulation and changes in the metabolic rate of individuals in office spaces was performed to establish the distribution of room temperatures at which individuals perceived a neutral thermal sensation. Subsequently, the indoor thermal environment in four offices was surveyed during the summer with different air-conditioning systems to determine the thermal environment stability in each case. The results revealed that for the required temperature, there was a noticeable difference between the average and most frequent values. Moreover, it was determined that the required temperature distribution is not normal, but rather, it is skewed to the low-temperature side. In addition, the radiant air-conditioning system was found to generate a narrow distribution of the equivalent temperature and hence, facilitated a more uniform thermal environment compared to a convective (multi-unit) air-conditioning system. Therefore, in buildings with convective air-conditioning systems, even if the planar average thermal environment is categorized as comfortable, it may be possible that workers who are sensitive to the cold or heat will complain of discomfort more frequently than those in buildings with radiant air-conditioning systems because the probability of workers sitting in cold- or hot-spot areas is higher in the former case.

Indoor Thermal Environment Research of Air Conditioning Office with Air from Window Gap

2013 ◽  
Vol 860-863 ◽  
pp. 1660-1665
Author(s):  
Ze Hua Liu ◽  
Yan Liao ◽  
Hao Ping Yu
Keyword(s):  
Numerical Simulation ◽  
Air Conditioning ◽  
Thermal Environment ◽  
Local Area ◽  
Indoor Thermal Environment ◽  
Air Infiltration ◽  
Air Supply ◽  
Field Velocity ◽  
Average Relative Humidity ◽  
Air Speed

The paper presents a numerical simulation study of indoor thermal environment of an air conditioning office in winter in Hengyang. Considering the effect of air infiltration from window gap, the distribution of indoor temperature field, velocity field and humidity field can be obtained when air supply angle is 45° down to the horizontal direction. Compared with simulation which air infiltration is ignored, the results show that average temperature of air conditioning area reduces 0.6 °C in Y = 1.1 m section. Air velocity is larger in Y = 1.1 m air conditioning zone. The air speed is greater than 0.2 m/s in local area, a sense blowing. Average relative humidity is larger in Y = 1.1 m air conditioning area. The research indicates that air infiltration can not be allowed to be neglected in numerical simulation.

Influence of Surface Boundary Conditions on Architectural Indoor Thermal Environment with Air Conditioning

2012 ◽  
Vol 170-173 ◽  
pp. 2756-2759
Author(s):  
Yuan Liang
Keyword(s):  
Boundary Condition ◽  
Boundary Conditions ◽  
Air Conditioning ◽  
Thermal Environment ◽  
Surface Boundary ◽  
Outdoor Air ◽  
Indoor Thermal Environment ◽  
Average Temperature ◽  
Environment Model ◽  
Surface Boundary Conditions

In order to analysis influence on indoor thermal environment with surface boundary which are the first boundary condition and the second boundary condition under the average temperature distributed hourly of the outdoor air, indoor thermal environment model of single architectural with air conditioning was established, and the indoor thermal environment was simulated by the CFD software. The results show that, there is a little influence between the two kinds of surface boundary conditions, and the two kinds of surface boundary conditions could be considered as equivalent.

scholarly journals Field Study on Energy-Saving Behaviour and Patterns of Air-Conditioning Use in a Condominium

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8572
Author(s):  
Kazui Yoshida ◽  
Hom B. Rijal ◽  
Kazuaki Bogaki ◽  
Ayako Mikami ◽  
Hiroto Abe
Keyword(s):  
Energy Saving ◽  
Air Conditioning ◽  
Energy Use ◽  
Thermal Environment ◽  
Residential Energy ◽  
Indoor Thermal Environment ◽  
Energy Management Systems ◽  
Home Energy Management ◽  
Questionnaire Surveys ◽  
Floor Heating

In the international movement to combat the threat of climate change, the timely implementation of residential energy-saving practises is becoming an urgent issue. Because the number of apartments is increasing, we analysed data from home energy management systems (HEMSs) and data from questionnaire surveys of 309 households in a condominium. We focused on the seasonal variation in air-conditioning (AC) use in living-dining rooms to determine the tendency of energy use for heating/cooling related to the characteristics of flats, the profiles of residents, and energy-saving behaviours. In winter, 80% of residents mainly used gas floor heating rather than AC and 24% did not use AC in winter. In households where someone stays home for long hours, they prefer gas floor heating rather than AC in winter. These households also tend to engage in energy-saving behaviours to adjust the indoor thermal environment. There are several types of energy-saving lifestyles; therefore, effective energy-saving measures should be considered for both energy efficiency and the thermal comfort of residents.

Analysis on electricity use and indoor thermal environment for typical air-conditioning residential buildings in Malaysia

Urban Climate ◽  
2021 ◽  
Vol 37 ◽  
pp. 100830
Author(s):  
Naja Aqilah ◽  
Sheikh Ahmad Zaki ◽  
Aya Hagishima ◽  
Hom Bahadur Rijal ◽  
Fitri Yakub
Keyword(s):  
Air Conditioning ◽  
Thermal Environment ◽  
Residential Buildings ◽  
Indoor Thermal Environment ◽  
Electricity Use

Analysis of Internet Bar Use Evaporative Air-Conditioning and Ventilation of Thermal Comfort

2011 ◽  
Vol 393-395 ◽  
pp. 1106-1109
Author(s):  
Huang Xiang ◽  
Wei Wang ◽  
Sheng Wu
Keyword(s):  
Relative Humidity ◽  
Air Conditioning ◽  
Thermal Environment ◽  
Internal Heat ◽  
Air Velocity ◽  
Factors Affecting ◽  
Indoor Thermal Environment ◽  
Heat Sensation ◽  
Environment Quality ◽  
Sensitivity Factors

The factors affecting indoor thermal environment are briefly introduced in this article, and one Internet bar was tested and analyzed that used evaporative air-conditioning in lanzhou, gansu. Meanwhile, through the air temperature, the relative humidity and air velocity of sensitivity factors were analyzed that heat sensation to human body, changed the heat sensation for people's from qualitative to the quantitative. As one way and the basis has provided for the improvement room internal heat environment quality.

Influence by Ventilation with Nature Wind on the Air Conditioning Energy Consumption

2013 ◽  
Vol 316-317 ◽  
pp. 1128-1132
Author(s):  
Ya Zhou Jing ◽  
Guo Jun Zhao ◽  
Hai Shan Li ◽  
Yan Gao
Keyword(s):  
Energy Consumption ◽  
Air Conditioning ◽  
Natural Ventilation ◽  
Thermal Environment ◽  
Indoor Thermal Environment ◽  
Natural Wind

In this paper, it reveals that the ventilation using patterns can do much to the energy consumption for air-conditioning. In the simulation, it models the person behavior with their action for regulating indoor thermal environment by opening the window for natural ventilation, and compares the influence by ventilation in different patterns to the air conditioning energy consumption. The results show that in the pattern priority for using the natural wind it is helpful for reducing the energy consumption.

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