Thermal comfort control via air conditioning system using fuzzy neural network feedback controller

<span>Despite their complexity and uncertainty, air conditioning systems should provide the optimal thermal conditions in a building. These controller systems should be adaptable to changes in environmental parameters. In most air conditioning systems, today, there are On/Off controllers or PID in more advanced types, which, due to different environmental conditions, are not optimal and cannot provide the optimal environmental conditions. Controlling thermal comfort of an air conditioning system requires estimation of thermal comfort index. In this study, fuzzy controller was used to provide thermal comfort in an air conditioning system, and neural network was used to estimate thermal comfort in the feedback path of the controller. Fuzzy controller has a good response given the non-linear features of air conditioning systems. In addition, the neural network makes it possible to use thermal comfort feedback in a real-time control.</span>

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Effect of Air Conditioning Position on Thermal Comfort in the Floor Air Conditioning System

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.493.74 ◽

2014 ◽

Vol 493 ◽

pp. 74-79

Author(s):

Y.A. Sabtalistia ◽

S.N.N. Ekasiwi ◽

B. Iskandriawan

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Energy Consumption ◽

Thermal Comfort ◽

Energy Efficient ◽

Air Conditioning ◽

Air Conditioning System ◽

Air Supply ◽

Air Conditioning Systems ◽

Air Diffusion

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.

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A dynamic model for human thermal comfort for smart building applications

Proceedings of the Institution of Mechanical Engineers Part I Journal of Systems and Control Engineering ◽

10.1177/0959651819865795 ◽

2019 ◽

Vol 234 (4) ◽

pp. 472-483

Author(s):

Ghezlane Halhoul Merabet ◽

Mohamed Essaaidi ◽

Driss Benhaddou

Keyword(s):

Thermal Comfort ◽

Air Conditioning ◽

Research Work ◽

Comfort Level ◽

Indoor Environments ◽

Air Conditioning System ◽

Human Thermal Comfort ◽

Local Quality ◽

Set Up ◽

Air Conditioning Systems

Thermal comfort is closely related to the evaluation of heating, ventilation, and air conditioning systems. It can be seen as the result of the perception of the occupants of a given environment, and it is the product of the interaction of a number of personal and environmental factors. Otherwise, comfort issues still do not play an important role in the daily operation of commercial buildings. However, in the workplace, local quality effects, in addition to the health, the productivity that has a significant impact on the performance of the activities. In this regard, researchers have conducted, for decades, investigations related to thermal comfort and indoor environments, which includes developing models and indices through experimentations to establish standards to evaluate comfort and factors and set-up parameters for heating, ventilation, and air conditioning systems. However, to our best knowledge, most of the research work reported in the literature deals only with parameters that are not dynamically tracked. This work aims to propose a prototype for comfort measuring through a wireless sensor network and then presenting a model for thermal comfort prediction. The developed model can be used to set up a heating, ventilation, and air conditioning system to meet the expected comfort level. In particular, the obtained results show that there is a strong correlation between users’ comfort and variables such as age, gender, and body mass index as a function of height and weight.

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CFD Study on Thermal Implication towards Human Body in Office Environment

Journal of Advanced Research in Fluid Mechanics and Thermal Sciences ◽

10.37934/arfmts.85.1.125134 ◽

2021 ◽

Vol 85 (1) ◽

pp. 125-134

Author(s):

Ahmad Rasdan Ismail ◽

Norfadzilah Jusoh ◽

Nor Kamilah Makhtar ◽

Nor Kamaliana Khamis ◽

Raemy Md Zein ◽

...

Keyword(s):

Air Conditioning ◽

Work Productivity ◽

Environmental Parameters ◽

Thermal Conditions ◽

Air Conditioning System ◽

Operative Temperature ◽

Office Environment ◽

Computational Fluid Dynamics Simulations ◽

Dynamics Simulations ◽

Radiant Temperature

Temperatures are rising gradually around the world due to the issue of global warming. This condition also affects those who have to work for long hours. A comfortable work environment helps employees to increase work productivity. Thermal comfort is the occupant’s satisfaction with the surrounding thermal conditions. Therefore, the objective of this study is to evaluate the thermal environmental conditions of air conditioning through Computational Fluid Dynamics simulations. The distributions of environmental parameters such as air velocity, air temperature, radiant temperature, inside an o?ce room with air-conditioning are presented. Based on these distributions, spatial pro?les of Predicted Mean Vote Index (PMV) are obtained to illustrate thermal conditions intuitively. This study was conducted under controlled environment inside special laboratory. To achieve this model office environment has been built in an environmental chamber. The distribution of PMV indicates that operative temperature at the 23 oC shows that the PMV is comfortable. The value of PMV in operative temperature at 23 oC is 0.79 near the skin of an occupant. The research outputs provide useful information for designers of the air-conditioning system to build a comfortable indoor environment in the office environment.

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Experimental Study and Analysis of Thermal Comfort in a University Campus Building in Tropical Climate

Sustainability ◽

10.3390/su12218886 ◽

2020 ◽

Vol 12 (21) ◽

pp. 8886

Author(s):

Milen Balbis-Morejón ◽

Javier M. Rey-Hernández ◽

Carlos Amaris-Castilla ◽

Eloy Velasco-Gómez ◽

Julio F. San José-Alonso ◽

...

Keyword(s):

Thermal Comfort ◽

Air Conditioning ◽

Thermal Environment ◽

Thermal Sensation ◽

Thermal Sensitivity ◽

Tropical Climate ◽

Air Conditioning System ◽

Humidity Measurements ◽

Air Conditioning Systems ◽

Thermal Preferences

This study presents the evaluation of the performance and acceptability of thermal comfort by students in the classrooms of a university building with minisplit-type air-conditioning systems, in a tropical climate. To carry out the study, temperature and humidity measurements were recorded, both outside and inside the selected classrooms, while the students were asked to complete thermal surveys on site. The survey model is based on the template proposed by Fanger and it was applied to a total number of 584 students. In each classroom, the Predicted Mean Vote (PMV) and the Predicted Percentage Dissatisfied (PPD) were estimated according to Fanger’s methodology, as well as the Thermal Sensation Vote (TSV) and the Actual Percentage Dissatisfied (APD), which were obtained from the measurements and the surveys. The results of this study showed that the PMV values, although they may vary with the insulation of the clothing, do not affect the TSV. Furthermore, comparing PMV vs. TSV scores, a 2 °C to 3 °C difference in operating temperature was found, whereby the thermal sensitivity for TSV was colder, so it could be assumed that the PMV model overestimates the thermal sensitivity of students in low-temperature conditions. In addition, an acceptability by 90% with thermal preferences between 23 °C and 24 °C were also found. These results indicate that it is possible to increase the temperature set point in minisplit-type air-conditioning system from 4 °C to 7 °C with respect to the currently set temperatures, without affecting the acceptability of the thermal environment to the students in the building.

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Multi-Circuit Air-Conditioning System Modelling for Temperature Control

Journal of Advanced Research in Fluid Mechanics and Thermal Sciences ◽

10.37934/arfmts.83.2.1424 ◽

2021 ◽

Vol 83 (2) ◽

pp. 14-24

Author(s):

Ibrahim Oleolo ◽

Hayati Abdullah ◽

Maziah Mohamad ◽

Mohammad Nazri Mohd Jaafar ◽

Akmal Baharain ◽

...

Keyword(s):

System Identification ◽

Thermal Comfort ◽

Air Conditioning ◽

Energy Savings ◽

Control Strategies ◽

Model Development ◽

Dynamic Modelling ◽

System Modelling ◽

Air Conditioning System ◽

Air Conditioning Systems

The suitable application of innovative control strategies in Heating, Ventilation, and Air-conditioning systems is important to improving the energy efficiency and maintenance of temperature set point to improve thermal comfort in buildings. The increased focus on energy savings and appropriate thermal comfort has resulted in the necessity for more dynamic approach to the use of these controllers. However, the design of these controllers requires the use of an accurate dynamic modelling. Substantial progresses have been made in the past on model development to provide better control strategy to ensure energy savings without sacrificing thermal comfort and indoor air quality in the Heating, Ventilation, and Air-conditioning systems. However, there are scarce model using the data driven approach in the Multi-circuit air-conditioning system. This research, carried out a study on the choice of a dynamic model for an operating centralized multi-circuit water-cooled package unit air-conditioning system using a system identification procedure. Baseline data were collected and analyzed, the model development was achieved by processing, estimating and validating the data in system identification. Result shows that the Autoregressive-moving average with exogenous terms (ARMAX) of the third order model, established the best model structure with the highest Best Fit and Lowest Mean Square Error.

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Utilizing Artificial Neural Network for Prediction of Occupants Thermal Comfort: A Case Study of a Test Room Fitted With a Thermoelectric Air-Conditioning System

IEEE Access ◽

10.1109/access.2020.2985036 ◽

2020 ◽

Vol 8 ◽

pp. 99709-99728 ◽

Cited By ~ 1

Author(s):

Kashif Irshad ◽

Asif Irshad Khan ◽

Sayed Ameenuddin Irfan ◽

Md. Mottahir Alam ◽

Abdulmohsen Almalawi ◽

...

Keyword(s):

Neural Network ◽

Artificial Neural Network ◽

Thermal Comfort ◽

Air Conditioning ◽

Air Conditioning System ◽

Test Room ◽

Artificial Neural

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ANALYSIS OF COMPETING VARIANTS OF AIR CONDITIONING SYSTEMS WITHOUT AIR EXTRACTION FROM ENGINES AT THE STAGE OF PASSENGER AIRCRAFT ONBOARD SYSTEMS CONCEPTUAL DESIGN

Computational nanotechnology ◽

10.33693/2313-223x-2019-6-3-86-91 ◽

2019 ◽

Vol 6 (3) ◽

pp. 80-85

Author(s):

Denis Igorevich Smagin ◽

Konstantin Igorevich Starostin ◽

Roman Sergeevich Savelyev ◽

Anatoly Anatolyevich Satin ◽

Anastasiya Romanovna Neveshkina ◽

...

Keyword(s):

Conceptual Design ◽

Air Conditioning ◽

Research University ◽

Cooling System ◽

Fuel Efficiency ◽

Air Cooling ◽

Moscow Aviation Institute ◽

Air Conditioning System ◽

Low Efficiency ◽

Air Conditioning Systems

One of the ways to achieve safety and comfort is to improve on-board air conditioning systems.The use of air cooling machine determines the air pressure high level at the point of selection from the aircraft engine compressor. Because of the aircraft operation in different modes and especially in the modes of small gas engines, deliberately high stages of selection have to be used for ensuring proper operation of the refrigeration machine in the modes of the aircraft small gas engines. Into force of this, most modes of aircraft operation have to throttle the pressure of the selected stage of selection, which, together with the low efficiency of the air cycle cooling system, makes the currently used air conditioning systems energy inefficient.A key feature of the architecture without air extraction from the main engines compressors is the use of electric drive compressors as a source of compressed air.A comparative analysis of competing variants of on-board air conditioning system without air extraction from engines for longrange aircraft projects was performed at the Moscow Aviation Institute (National Research University).The article deals with the main approaches to the decision-making process on the appearance of a promising aircraft on-board air conditioning system at the stage of its conceptual design and formulated the basic requirements for the structure of a complex criterion at different life cycle stages.The level of technical and technological risk, together with a larger installation weight, will require significant costs for development, testing, debugging and subsequent implementation, but at the same time on-board air conditioning system scheme without air extraction from the engines will achieve a significant increase in fuel efficiency at the level of the entire aircraft.

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Energy-efficient predictive control of indoor thermal comfort and air quality in a direct expansion air conditioning system

Applied Energy ◽

10.1016/j.apenergy.2017.03.076 ◽

2017 ◽

Vol 195 ◽

pp. 439-452 ◽

Cited By ~ 35

Author(s):

Jun Mei ◽

Xiaohua Xia

Keyword(s):

Air Quality ◽

Thermal Comfort ◽

Predictive Control ◽

Energy Efficient ◽

Air Conditioning ◽

Direct Expansion ◽

Air Conditioning System ◽

Indoor Thermal Comfort

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The study of solar absorption air-conditioning systems

Journal of Energy in Southern Africa ◽

10.17159/2413-3051/2005/v16i4a3103 ◽

2005 ◽

Vol 16 (4) ◽

pp. 59-66 ◽

Cited By ~ 10

Author(s):

V Mittal ◽

KS Kasana ◽

NS Thakur

Keyword(s):

Air Conditioning ◽

Lithium Bromide ◽

Cooling Systems ◽

Solar Absorption ◽

Air Conditioning System ◽

Heating And Cooling ◽

Absorption Cooling ◽

Solar Powered ◽

Solar Absorption Cooling ◽

Air Conditioning Systems

An air-conditioning system utilizing solar energy would generally be more efficient, cost wise, if it was used to provide both heating and cooling requirements in the building it serves. Various solar powered heating systems have been tested extensively, but solar powered air conditioning systems have received very little attention. Solar powered absorption cooling systems can serve both heating and cooling requirements in the building it serves. Many researchers have studied the solar absorption air conditioning system in order to make it economically and technically viable. But still, much more research in this area is needed. This paper will help many researchers working in this area and provide them with fundamental knowledge on absorption systems, and a detailed review on the past efforts in the field of solar absorption cooling systems with the absorption pair of lithium-bromide and water. This knowledge will help them to start the parametric study in order to investigate the influence of key parameters on the overall system performance.

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