Comparative research on the air pollutant prevention and thermal comfort for different types of ventilation

2020 ◽  
pp. 1420326X2092552
Author(s):  
Yang Zhang ◽  
Wenxuan Yu ◽  
Youli Li ◽  
Han Li
Keyword(s):  
Thermal Comfort ◽  
Cfd Simulation ◽  
Thermal Sensation ◽  
Side Wall ◽  
Air Pollutant ◽  
Indoor Thermal Comfort ◽  
Subjective Experiment ◽  
Different Types ◽  
Computational Fluid Dynamics Cfd ◽  
Indoor Comfort

In this article, a comparative study on the outdoor air pollutant prevention and indoor thermal comfort for different types of ventilation was carried out. Both objective experiment, subjective experiment and computational fluid dynamics (CFD) simulation were conducted to investigate the differences in air pollutant prevention and thermal comfort between four common ventilation methods, namely supplying on the ceiling and returning on the ceiling (SC-RC), supplying on the ceiling and returning on the side wall (SC-RSW), supplying on the side wall and returning on the ceiling (SSW-RC), and supplying on the side wall and returning on the side wall (SSW-RSW). Results show that SSW-RSW can provide the highest indoor air quality according to the indoor average PM2.5 concentration. Overall thermal sensation was introduced to evaluate the indoor comfort under the four ventilation methods. The voting results show that the indoor thermal comfort can be enhanced by 29–36% under SSW-RSW and SSW-RC. Therefore, SSW-RSW is more suitable for providing a healthy and comfortable indoor environment.

scholarly journals Research on the effect of the size of the wall-hanging air-conditioner indoor unit on the indoor thermal comfort

2020 ◽  
Author(s):  
Kuanbing Caozhu ◽  
Changfa Ji
Keyword(s):  
Temperature Distribution ◽  
Thermal Comfort ◽  
Indoor Air ◽  
Thermal Sensation ◽  
Air Conditioner ◽  
Turbulent Model ◽  
Indoor Temperature ◽  
Indoor Thermal Comfort ◽  
Fluent Software ◽  
Indoor Comfort

Abstract The geometrical dimension of the wall-hanging air-conditioner indoor unit affects the indoor thermal comfort. In this paper, fluent software is used and standard k-e two equation turbulent model is chosen to carry out the simulation of the indoor temperature field and flow field of six different sizes of the single wall-hanging indoor air-conditioner in the room. The temperature distribution, velocity distribution and PMV distribution of the plane which is 1.8 m from the ground are given. It can be known that under the condition of six kinds of sizes of the wall-hanging air-conditioner indoor unit, when the size of the air-conditioner indoor unit is 0.4m × 0.2m × 0.2 m, the temperature variation at the z = 1.8 m section is relatively small, the temperature distribution is more uniform. When the size of the air-conditioner indoor unit is 0.5m × 0.2m × 0.2 m, the temperature difference at the z = 1.8 m section is relatively smaller, PMV is closest to 0, and the thermal sensation is almost moderate. Therefore when the size of the air-conditioner indoor unit is 0.5m × 0.2m × 0.2 m, better indoor comfort can be achieved.

scholarly journals Predicted Medium Vote Thermal Comfort Analysis Applying Energy Simulations with Phase Change Materials for Very Hot-Humid Climates in Social Housing in Ecuador

2021 ◽  
Vol 13 (3) ◽  
pp. 1257
Author(s):  
Luis Godoy-Vaca ◽  
E. Catalina Vallejo-Coral ◽  
Javier Martínez-Gómez ◽  
Marco Orozco ◽  
Geovanna Villacreses
Keyword(s):  
Thermal Comfort ◽  
Phase Change ◽  
Social Housing ◽  
Energy Demand ◽  
Phase Change Materials ◽  
Thermal Sensation ◽  
Electricity Consumption ◽  
Different Types ◽  
Climate Influences ◽  
Energy Simulations

This work aims to estimate the expected hours of Predicted Medium Vote (PMV) thermal comfort in Ecuadorian social housing houses applying energy simulations with Phase Change Materials (PCMs) for very hot-humid climates. First, a novel methodology for characterizing three different types of social housing is presented based on a space-time analysis of the electricity consumption in a residential complex. Next, the increase in energy demand under climate influences is analyzed. Moreover, with the goal of enlarging the time of thermal comfort inside the houses, the most suitable PCM for them is determined. This paper includes both simulations and comparisons of thermal behavior by means of the PMV methodology of four types of PCMs selected. From the performed energy simulations, the results show that changing the deck and using RT25-RT30 in walls, it is possible to increase the duration of thermal comfort in at least one of the three analyzed houses. The applied PCM showed 46% of comfortable hours and a reduction of 937 h in which the thermal sensation varies from “very hot” to “hot”. Additionally, the usage time of air conditioning decreases, assuring the thermal comfort for the inhabitants during a higher number of hours per day.

scholarly journals Indoor Thermal Comfort Analysis: A Case Study of Modern and Traditional Buildings in Hot-Arid Climatic Region of Ethiopia

Urban Science ◽  
2021 ◽  
Vol 5 (3) ◽  
pp. 53
Author(s):  
Haven Hailu ◽  
Eshetu Gelan ◽  
Yared Girma
Keyword(s):  
Thermal Comfort ◽  
Significant Role ◽  
Indoor Environment ◽  
Thermal Sensation ◽  
Climatic Region ◽  
Contributing Factors ◽  
Objective Measurements ◽  
Indoor Thermal Comfort ◽  
Adaptive Comfort

Indoor thermal comfort is an essential aspect of sustainable architecture and it is critical in maintaining a safe indoor environment. Expectations, acceptability, and preferences of traditional and modern buildings are different in terms of thermal comfort. This study, therefore, attempts to evaluate the indoor thermal comforts of modern and traditional buildings and identify the contributing factors that impede or facilitate indoor thermal comfort in Semera city, Ethiopia. This study employed subjective and objective measurements. The subjective measurement is based on the ASHRAE seven-point thermal sensation scale. An adaptive comfort model was employed according to the ASHRAE standard to evaluate indoor thermal comfort. The results revealed that with regards to thermal sensational votes between −1 and +1, 88% of the respondents are satisfied with the indoor environment in traditional houses, while in modern houses this figure is 22%. Likewise, 83% of occupants in traditional houses expressed a preference for their homes to remain the same or be only slightly cooler or warmer. Traditional houses were, on average, in compliance with the 80% acceptability band of the adaptive comfort standard. The study investigated that traditional building techniques and materials, in combination with consideration of microclimate, were found to play a significant role in regulating the indoor environment.

From Construction to Operation: Achieving Indoor Thermal Comfort via Altering External Walls Specifications in Egypt

2013 ◽  
Vol 689 ◽  
pp. 250-253 ◽  
Author(s):  
Mohamed M. Mahdy ◽  
Marialena Nikolopoulou
Keyword(s):  
Energy Consumption ◽  
Thermal Comfort ◽  
Natural Ventilation ◽  
Minimum Energy ◽  
Residential Energy ◽  
Indoor Thermal Comfort ◽  
Minimum Energy Consumption ◽  
Different Types ◽  
Running Cost ◽  
The Cost

The objective of this research is to study the effect of using different material specifications for the external walls on the cost of the energy consumption for achieving internal thermal comfort. We refer to this as operation running cost, which in turn is compared to initial construction cost for each type of the used external walls. In order to achieve this objective, dynamic thermal simulation were carried out for four different types of external walls – commonly used in Egypt – in two different sets of cooling: natural ventilation and mechanical means. Experiments recommend that using the Egyptian Residential Energy Code (EREC) to achieve inner thermal comfort with the minimum energy consumption (consequently the minimum CO2 emissions) and the minimum running cost as well.

IMPROVEMENT OF THERMAL COMFORT INSIDE A MOSQUE BUILDING

2016 ◽  
Vol 78 (8-4) ◽  
Author(s):  
Fawaz Ghaleb Noman ◽  
Nazri Kamsah ◽  
Haslinda Mohamed Kamar
Keyword(s):  
Thermal Comfort ◽  
Natural Ventilation ◽  
Ventilation System ◽  
Side Wall ◽  
The West ◽  
Cfd Simulations ◽  
Interior Space ◽  
Flow Simulations ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method

A combined natural ventilation and mechanical fans are commonly used to cool the interior space inside the mosques in Malaysia. This article presents a study on thermal comfort in the Al-Jawahir Mosque, located in Johor Bahru, Malaysia. The objective is to assess the thermal comfort inside the mosque under the present ventilation system by determining the Predicted Mean Vote (PMV) and the Predicted Percentage of Dissatisfied (PPD). These values were then compared to the limits stated in the ASHRAE Standard-55. It was found that the PMV varies from 1.68 to 2.26 while the PPD varies from 61% to 87%. These show that the condition inside the mosque is quite warm. Computational fluid dynamics (CFD) method was used to carry out flow simulations, to identify a suitable strategy to improve the thermal comfort inside the mosque. Results of CFD simulations show that installing four exhaust fans above the windows on the west-side wall of the mosque is the most effective strategy to improve the thermal comfort inside the mosque. Both the PMV and PPD values can potentially be reduced by more than 60%.

A Data-Driven Thermal Sensation Model Based Predictive Controller for Indoor Thermal Comfort and Energy Optimization

2014 ◽  
Author(s):  
Xiao Chen ◽  
Qian Wang
Keyword(s):  
Thermal Comfort ◽  
Thermal Sensation ◽  
Energy Optimization ◽  
Data Driven ◽  
Air Velocity ◽  
Comfort Index ◽  
Indoor Thermal Comfort ◽  
Occupant Feedback ◽  
Predictive Controller ◽  
Radiant Temperature

This paper proposes a model predictive controller (MPC) using a data-driven thermal sensation model for indoor thermal comfort and energy optimization. The uniqueness of this empirical thermal sensation model lies in that it uses feedback from occupants (occupant actual votes) to improve the accuracy of model prediction. We evaluated the performance of our controller by comparing it with other MPC controllers developed using the Predicted Mean Vote (PMV) model as thermal comfort index. The simulation results demonstrate that in general our controller achieves a comparable level of energy consumption and comfort while eases the computation demand posed by using the PMV model in the MPC formulation. It is also worth pointing out that since we assume that our controller receives occupant feedback (votes) on thermal comfort, we do not need to monitor the parameters such as relative humidity, air velocity, mean radiant temperature and occupant clothing level changes which are necessary in the computation of PMV index. Furthermore simulations show that in cases where occupants’ actual sensation votes might deviate from the PMV predictions (i.e., a bias associated with PMV), our controller has the potential to outperform the PMV based MPC controller by providing a better indoor thermal comfort.

Numerical Investigation on Ventilation Strategy for Laboratories: An Approach to Control Thermal Comfort and Air Quality Using Active Chilled Beams

2007 ◽  
Author(s):  
Farhad Memarzadeh ◽  
Jane Jiang ◽  
Andy Manning
Keyword(s):  
Air Quality ◽  
Thermal Comfort ◽  
Flow Rate ◽  
Cfd Simulation ◽  
Washington Dc ◽  
Ventilation Strategy ◽  
Flow Rates ◽  
Beam System ◽  
Computational Fluid Dynamics Cfd ◽  
Lower Flow Rate

Laboratories are usually equipment intensive. The supply flow rates required to cool these laboratories are generally higher than in a less equipment intensive zone of the building. The thermal comfort of occupants in laboratories can be controlled by the choice of ventilation strategy. This study employs Computational Fluid Dynamics (CFD) simulation to assess the performance of active chilled beams in a general laboratory layout with some equipment intensive areas and the removal effectiveness of such a system. The chilled beam performance is also compared with at of ceiling diffusers. The results from this study show that the chilled beams improve thermal comfort, and they can be operated at as low as 4 ACH while maintaining very satisfactory average PPD (around 10%) in the occupied zones. The chilled beam system also improves removal effectiveness because of the inherent higher total supply flow rate that results in a better mixing in the room than ceiling diffusers. The chilled beams in the cases studied are seen to have an insignificant effect on the hood containment. As satisfactory thermal comfort and air quality can be achieved at a lower flow rate in comparison with all-air ceiling diffusers, a 14% saving is estimated in annual energy cost for cooling and ventilating a typical lab in the Washington DC area.

scholarly journals Optimization of Architectural Form for Thermal Comfort in Naturally Ventilated Gymnasium at Hot and Humid Climate by Orthogonal Experiment

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3228
Author(s):  
Xiaodan Huang ◽  
Qingyuan Zhang ◽  
Ineko Tanaka
Keyword(s):  
Thermal Comfort ◽  
Thermal Sensation ◽  
Orthogonal Experiment ◽  
Range Analysis ◽  
Humid Climate ◽  
Architectural Form ◽  
Healthy Environment ◽  
Average Value ◽  
Indoor Thermal Comfort ◽  
Hot And Humid Climate

As the gymnasiums in subtropical region with hot and humid climate are naturally ventilated during non-competition periods, occupants exercising indoors often feel uncomfortable, especially in summer. In order to provide thermally comfortable and healthy environment for the occupants, the design on architectural form is found to be an effective solution on improving indoor thermal comfort of naturally ventilated gymnasiums. Therefore, a new perspective regarding optimization of naturally ventilated gymnasiums is proposed in the aspect of the architectural form. This paper presents the optimization of architectural form in naturally ventilated gymnasiums in which simulation and orthogonal experiment methods are combined. Through numerical simulation with FlowDesigner software, the significance of architectural form affecting indoor thermal comfort has been given, and the optimal architectural forms of naturally ventilated gymnasium are determined. The results show that the roof insulation type is the most significant factor influencing indoor thermal comfort; thus, it should be considered primarily in optimization. Moreover, the range analysis and variance analysis reveal the rankings of the factors for the gymnasium thermal comfort. In addition, it is demonstrated that the optimal gymnasium model, when compared with the initial gymnasium model, has a satisfactory effect on improving the indoor thermal comfort, as the average value of Predicted Thermal Sensation (PTS) in August decreased from 1.11 (Slightly hot) to 0.86 (Comfortable). This study provides a new insight for the designers in optimizing the architectural form of gymnasiums for achieving the indoor thermal comfort at hot and humid climate.

scholarly journals Ventilation Characteristics and Performance Evaluation of Different Window-Opening Forms in a Typical Office Room

2021 ◽  
Vol 11 (19) ◽  
pp. 8966
Author(s):  
Yuanyuan Wang ◽  
Yanzhe Yu ◽  
Tianzhen Ye ◽  
Quan Bo
Keyword(s):  
Thermal Comfort ◽  
Natural Ventilation ◽  
Cfd Simulation ◽  
Thermal Sensation ◽  
Ventilation Rate ◽  
Window Opening ◽  
Ventilation Modes ◽  
Ventilation Performance ◽  
Scale Experiment ◽  
And Performance

As most existing office buildings in China lack fresh air systems for ventilation, natural ventilation with windows remains the main means of improving indoor air quality and adjusting indoor thermal comfort. However, knowledge of the ventilation characteristics of various window-opening forms in actual buildings is limited and current methods for evaluating ventilation performance lack a comprehensive consideration of ventilation rate and thermal comfort. In this study, the ventilation characteristics of different window-opening forms were systematically compared by conducting computational fluid dynamics (CFD) simulations. A full-scale experiment was conducted in a typical office room in a university in Tianjin to validate the CFD simulation. Two ventilation modes (wind-driven cross-ventilation and temperature-driven single-sided ventilation), three window-opening angles, and seven window types were investigated. Additionally, the ratio of the ventilation rate to the absolute value of thermal sensation was used to quantify the indoor natural-ventilation performance. The results showed that a sliding window with a full opening has the highest discharge coefficients of 0.68 and 0.52 under wind-driven cross-ventilation and temperature-driven single-sided ventilation, respectively, and top-hung windows opening both inwards and outwards have better ventilation performance than other window types under the two ventilation modes. This study is applicable to the design and practice of natural ventilation.

Indoor Thermal Comfort and its Effect on Building Energy Consumption

2011 ◽  
Vol 71-78 ◽  
pp. 3516-3519 ◽  
Author(s):  
Xue Bin Yang ◽  
De Fa Sun ◽  
Xiang Jiang Zhou ◽  
Ling Ling Cai ◽  
Ying Ji
Keyword(s):  
Energy Consumption ◽  
Thermal Comfort ◽  
Energy Savings ◽  
Thermal Sensation ◽  
Building Energy ◽  
Building Energy Consumption ◽  
Predicted Mean Vote ◽  
Indoor Thermal Comfort ◽  
Air Speed ◽  
Comfort Parameters

The indoor thermal comfort and its effect on building energy consumption have been conducted by literature reviewing in the study. The linear relationship and the related formulations of various thermal comfort indictors are summarized to evaluate the human comfort. These parameters include predicted mean vote, thermal sensation vote, adaptive predicted mean vote, thermal comfort vote, and thermal acceptability. Under different climatic or regional conditions, both relationships between thermal comfort parameters and indoor or outdoor air temperature, and between comfort vote and another comfort parameter, are summarized for their definition and formulation. The comfort parameters such as local air speed, neutral temperature, PMV set point and others will directly impact the building energy usage. It is of significance to seek an optimal alternative for energy savings.

Sign in / Sign up

Export Citation Format

Share Document