scholarly journals Thermal Comfort Study Based on PMV-PPD in the Building of a Screening Center for COVID-19

Author(s):  
Danial Mohammadi ◽  
Simin Nasrabadi

Background: One way to achieve a standard heating, ventilating, and air conditioning system with maximum satisfaction is to use a thermal index to identify and determine the thermal comfort of people. In this study we intend to evaluate thermal comfort based on PMV-PPD (Predicted Mean Vote/Predicted Percentage Dissatisfied) model in workers of screening center for COVID-19. Methods: The study period was from March 1 to October 31, 2020. In this study, we used the ISO 7730 model to determinate PMV-PPD index. PMV index was used to determine thermal comfort at different scales in Birjand city with arid and hot climate. All data were analyzed using R software (version 3.3.0) and IBM SPSS statistics softwares. Results: The maximum and minimum recorded physical PMV values in the study period were observed in June as (2.09 ± 0.03) and March as (-1.27 ± 0.14), respectively. The amplitude of the thermal sense in the study period was varied between slightly cool (-1.5) and warm (+2.5). The PPD in spring was 40% which indicated slightly warm to hot condition. Conclusions: The October was the only month during the study in which thermal stress was in comfort or neutral thermal condition.  Our results suggest that thermal comfort has dimensions and indices which are helpful in managing energy consumption.

2014 ◽  
Vol 493 ◽  
pp. 74-79
Author(s):  
Y.A. Sabtalistia ◽  
S.N.N. Ekasiwi ◽  
B. Iskandriawan

Energy consumption for air conditioning systems (air conditioning system) increased along with the increasing need for fresh air and comfortable in the room especially apartments. FAC system (Floor Air Conditioning) is growing because it is more energy efficient than CAC (Ceiling Air Conditioning) system. However, the position of the AC supply is on the lower level at the FAC system causes draft discomfort becomes greater as air supply closer to the occupants so that thermal comfort can be reduced. Heat mixture of windows, exterior walls, kitchen, and occupants in the studio apartment affect thermal comfort in the room too.This study aims to determine the position of the AC supply which has the best thermal comfort of FAC system in the studio apartment. It can be done by analyzing ADPI (Air Diffusion Performance Index), the distribution of air temperature, wind speed, RH (Relative Humidity), and DR (Draft Risk) to change the position of the AC supply supported by CFD (Computational Fluid Dynamics) simulation.This result prove that AC position 2 (on wall near the kitchen) is more comfortable than AC position 1 (on the bathroom wall) because AC position 2 away from occupied areas, thereby reducing the occurrence of draught discomfort.


Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1996
Author(s):  
Ruixin Lv ◽  
Zhongyuan Yuan ◽  
Bo Lei ◽  
Jiacheng Zheng ◽  
Xiujing Luo

A model predictive control (MPC) system with an adaptive building model based on thermal-electrical analogy for the hybrid air conditioning system using the radiant floor and all-air system for heating is proposed in this paper to solve the heating supply control difficulties of the railway station on Tibetan Plateau. The MPC controller applies an off-line method of updating the building model to improve the accuracy of predicting indoor conditions. The control performance of the adaptive MPC is compared with the proportional-integral-derivative (PID) control, as well as an MPC without adaptive model through simulation constructed based on a TRNSYS-MATLAB co-simulation testbed. The results show that the implementation of the adaptive MPC can improve indoor thermal comfort and reduce 22.2% energy consumption compared to the PID control. Compared to the MPC without adaptive model, the adaptive MPC achieves fewer violations of constraints and reduces energy consumption by 11.5% through periodic model updating. This study focuses on the design of a control system to maintain indoor thermal comfort and improve system efficiency. The proposed method could also be applied in other public buildings.


2016 ◽  
Vol 78 (8-4) ◽  
Author(s):  
Henry Nasution ◽  
Afiq Aiman Dahlan ◽  
Azhar Abdul Aziz ◽  
Ulul Azmi ◽  
Sumeru Sumeru ◽  
...  

PID control system for air-conditioning system in residence is presented in this manuscript. The control strategy is focused on low energy consumption and thermal comfort for indoor user. The algorithm is developed to control the compressor speed at an appropriate speed according to the temperature inside the controlled area using PID controller. Software is developed to measure and interface the system with controlling the system according to the algorithm. The temperature settings are 20, 22 and 24oC with internal heat load of 0 and 1000 Watt. The results obtained proved that the technique can lower the energy consumption and increased temperature control for better thermal comfort compared to on/off controller


2015 ◽  
Vol 77 (28) ◽  
Author(s):  
Aidil Sukri Ahmad ◽  
S. A. Abdul Shukor ◽  
Karl Kohlhof ◽  
Zul Azhar Zahid Jamal ◽  
Azizul Mohamad

The usage of air conditioning system to create a thermally comfortable environment in tropical countries is often a must, not necessarily luxurious any longer. However, the extreme usage of the system will lead towards higher consumption of energy and higher cost. A promising energy efficient model developed based on the Predictive Mean Vote (PMV) is analyzed and evaluated here to distinguish its workability. This model only requires the user to enter their respective PMV value (from -1 to +1) and the respective parameters will be inserted into the air conditioning system, which is based on the standard thermal comfort ISO 7730. Analyses and evaluations were done based on the measurements from human subjects and their feelings towards the surroundings were recorded to see the performance of the model. From here, more than 91% of the subjects agree with the parameters used in defining their thermal comfort. This proves the workability of the model towards controlling the air conditioning system in creating a thermal comfort ambience at lower energy consumption, and further simulative investigations are appreciated before implementation.


Author(s):  
Luiz Bueno da Silva ◽  
Francisco Antonio P. Fialho ◽  
Antonio Souto Coutinho ◽  
da F. Lima Márcio Botelho ◽  
P. Xavier Antonio de Augusto

This paper presents an investigation hold on a Bank Agency Compensation Department about the correlation between productivity and thermal dissatisfaction indicators, through the use of Pearson's coefficient (r). The criteria for measuring thermal comfort conditions were based on PMV indexes (Predicted Mean Vote), and PPD (Predicted Percentage of Dissatisfied), according ISO 7730/1994 norm. Productivity was measured through the use of a computer program developed for running in a UNIX platform. The results show a meaningful correlation between thermal dissatisfaction and productivity, when the central air conditioning system was working satisfactorily.


2010 ◽  
Vol 171-172 ◽  
pp. 159-162
Author(s):  
Wei Cai ◽  
Ke Jian Cai ◽  
Zhao Hui Wu

Large-scale public buildings have high energy density, which take big part of the gross energy consumption in buildings in China. It is still in attempting stage about the strategy of energy conservation in air conditioning systems. The objective of this study is to investigate that how to appropriately divide central air conditioning system zoning by using simulation software to calculate the basis dynamic temperature and load in typical large-scale public buildings. Effects of weather conditions, building envelope conditions and building structure on large-scale public building energy consumption were analyzed in this simulation. The results show that the building load is the fundamental factor involved in air conditioning system zoning. Surplus heat recovery in inner zone is also recommended to maintain inner zone comfort and energy conservation. This work provides the theoretical and technological basis for study on central air conditioning system zoning and thermal comfort for large-scale public building.


2019 ◽  
pp. 53-65
Author(s):  
Renata Domingos ◽  
Emeli Guarda ◽  
Elaise Gabriel ◽  
João Sanches

In the last decades, many studies have shown ample evidence that the existence of trees and vegetation around buildings can contribute to reduce the demand for energy by cooling and heating. The use of green areas in the urban environment as an effective strategy in reducing the cooling load of buildings has attracted much attention, though there is a lack of quantitative actions to apply the general idea to a specific building or location. Due to the large-scale construction of high buildings, large amounts of solar radiation are reflected and stored in the canyons of the streets. This causes higher air temperature and surface temperature in city areas compared to the rural environment and, consequently, deteriorates the urban heat island effect. The constant high temperatures lead to more air conditioning demand time, which results in a significant increase in building energy consumption. In general, the shade of the trees reduces the building energy demand for air conditioning, reducing solar radiation on the walls and roofs. The increase of urban green spaces has been extensively accepted as effective in mitigating the effects of heat island and reducing energy use in buildings. However, by influencing temperatures, especially extreme, it is likely that trees also affect human health, an important economic variable of interest. Since human behavior has a major influence on maintaining environmental quality, today's urban problems such as air and water pollution, floods, excessive noise, cause serious damage to the physical and mental health of the population. By minimizing these problems, vegetation (especially trees) is generally known to provide a range of ecosystem services such as rainwater reduction, air pollution mitigation, noise reduction, etc. This study focuses on the functions of temperature regulation, improvement of external thermal comfort and cooling energy reduction, so it aims to evaluate the influence of trees on the energy consumption of a house in the mid-western Brazil, located at latitude 15 ° S, in the center of South America. The methodology adopted was computer simulation, analyzing two scenarios that deal with issues such as the influence of vegetation and tree shade on the energy consumption of a building. In this way, the methodological procedures were divided into three stages: climatic contextualization of the study region; definition of a basic dwelling, of the thermophysical properties; computational simulation for quantification of energy consumption for the four facade orientations. The results show that the façades orientated to north, east and south, without the insertion of arboreal shading, obtained higher values of annual energy consumption. With the adoption of shading, the facades obtained a consumption reduction of around 7,4%. It is concluded that shading vegetation can bring significant climatic contribution to the interior of built environments and, consequently, reduction in energy consumption, promoting improvements in the thermal comfort conditions of users.


Symmetry ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 344
Author(s):  
Alejandro Humberto García Ruiz ◽  
Salvador Ibarra Martínez ◽  
José Antonio Castán Rocha ◽  
Jesús David Terán Villanueva ◽  
Julio Laria Menchaca ◽  
...  

Electricity is one of the most important resources for the growth and sustainability of the population. This paper assesses the energy consumption and user satisfaction of a simulated air conditioning system controlled with two different optimization algorithms. The algorithms are a genetic algorithm (GA), implemented from the state of the art, and a non-dominated sorting genetic algorithm II (NSGA II) proposed in this paper; these algorithms control an air conditioning system considering user preferences. It is worth noting that we made several modifications to the objective function’s definition to make it more robust. The energy-saving optimization is essential to reduce CO2 emissions and economic costs; on the other hand, it is desirable for the user to feel comfortable, yet it will entail a higher energy consumption. Thus, we integrate user preferences with energy-saving on a single weighted function and a Pareto bi-objective problem to increase user satisfaction and decrease electrical energy consumption. To assess the experimentation, we constructed a simulator by training a backpropagation neural network with real data from a laboratory’s air conditioning system. According to the results, we conclude that NSGA II provides better results than the state of the art (GA) regarding user preferences and energy-saving.


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