Requirements of Air-Conditioning Systems’ Developments in Hospitals and Critical Healthcare Facilities

Volume 3 ◽  
2004 ◽  
Author(s):  
Essam E. Khalil ◽  
Ramiz Kameel
Keyword(s):  
Energy Consumption ◽  
Air Quality ◽  
Thermal Comfort ◽  
Air Conditioning ◽  
Hvac Systems ◽  
Comfort Level ◽  
Current Status ◽  
Healthcare Applications ◽  
Healthcare Facilities ◽  
Intelligent Technique

The balance between thermal comfort and air quality in healthcare facilities to optimize the Indoor Air Quality (IAQ) is the main aim of this paper. The present paper will present this balance from the viewpoint of the air conditioning design. It was found that the design of the HVAC airside systems plays an important role for achieving the optimum air quality beside the optimum comfort level. This paper highlights the importance of the proper airside design on the IAQ. The present paper introduces some recommendations for airside designs to facilitate the development of optimum HVAC systems. This paper also stresses on the factors that improve the thermal comfort and air quality for the already existed systems (for maintenance procedure). To design an optimum HVAC airside system that provides comfort and air quality in the air-conditioned spaces with efficient energy consumption is a great challenge. The present paper defines the current status, future requirements, and expectations. Based on this analysis and the vast progress of computers and associated software, the artificial intelligent technique will be a competitor candidate to the experimental and numerical techniques. Finally, the researches that relate between the different designs of the HVAC systems and energy consumption should concern with the optimization of airside design as the expected target to enhance the indoor environment. The present paper reviews the results of recent advances that are concerned with the HVAC design engineering in the healthcare applications. The following requirements are necessary for Health and hygiene considerations: • Air movements are to be restricted in and between the various hospital departments (no cross movement). • Appropriate ventilation and filtration is used to dilute and reduce contamination in the form of odour, air-borne micro organisms, viruses, hazardous chemical and radioactive substances. • Temperature and relative humidity are to be regulated and attained for various medical areas. • Environmental compliance conditions should be maintained, accurately controlled and monitored.

Energy Efficiency, Air Quality, and Comfort in Air-Conditioned Spaces

2003 ◽  
Author(s):  
Ramiz Kameel ◽  
Essam E. Khalil
Keyword(s):  
Energy Consumption ◽  
Air Quality ◽  
Indoor Environment ◽  
Evaluation Study ◽  
Hvac Systems ◽  
Current Status ◽  
Experimental Investigations ◽  
Intelligent Technique ◽  
Numerical Tools ◽  
Artificial Intelligent Technique

To design an optimum HVAC airside system that provides comfort and air quality in the air-conditioned spaces with efficient energy consumption is a great challenge. This paper evaluates recent progresses of HVAC airside design for the airconditioned spaces. The present evaluation study defines the current status, future requirements, and expectations. It has been found that, the experimental investigations should be considered in the new trend of studies, not to validate the numerical tools only, but also to provide a complete database of the airflow characteristics in the air-conditioned spaces. Based on this analysis and the vast progress of computers and associated software, the artificial intelligent technique will be a competitor candidate to the experimental and numerical techniques. Finally, the researches that relate between the different designs of the HVAC systems and energy consumption should concern with the optimization of airside design as the expected target to enhance the indoor environment.

scholarly journals Thermal comfort analysis in office buildings with different air-conditioning systems

2018 ◽  
Vol 9 (1) ◽  
pp. 59-63 ◽  
Author(s):  
J. Szabo ◽  
L. Kajtar
Keyword(s):  
Air Quality ◽  
Thermal Comfort ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Air Conditioning ◽  
Carbon Dioxide Concentration ◽  
Comfort Level ◽  
Office Buildings ◽  
Ducted Fan ◽  
Air Conditioning Systems

It is a prime aim to ensure a suitable comfort level in case of office buildings. The productivity of office employees is directly influenced by the comfort. Thermal discomfort and poor indoor air quality deteriorate the intensity and quality of human work. We investigated the comfort in office buildings with on-site measurements during the summer season. The office buildings were operating with different HVAC (Heating, Ventilating and Air-Conditioning) systems: ducted fan-coil with suspended ceiling, installation, non-ducted fan-coil with floor-mounted installation, active chilled beam with fresh air supply. We evaluated the thermal comfort under PMV (Predicted Mean Vote), PPD (Predicted Percentage of Dissatisfied), the local discomfort based on DR (Draught Rate) and the IAQ (Indoor Air Quality) based on carbon dioxide concentration. The comfort measurements were evaluated. The measurements were evaluated with scientific research methods, comfort categories based on the requirements of CR 1752. The results of this comparison were presented in this article.

scholarly journals Modeling and Experimental Investigation of Thermal Comfort and Energy Consumption in a Battery Electric Bus

2021 ◽  
Vol 12 (1) ◽  
pp. 7
Author(s):  
Francesco Cigarini ◽  
Tu-Anh Fay ◽  
Nikolay Artemenko ◽  
Dietmar Göhlich
Keyword(s):  
Energy Consumption ◽  
Thermal Comfort ◽  
Air Conditioning ◽  
Hvac Systems ◽  
State Of Charge ◽  
Hvac System ◽  
Data Logger ◽  
Winter Conditions ◽  
Electric Bus ◽  
Thermal Comfort Model

In battery electric buses (e-buses), the substantial energy consumption of the heating, ventilation, and air conditioning (HVAC) system can cause significant reductions of the available travel range. Additionally, HVAC systems are often operated at higher levels than what required for the thermal comfort of the passengers. Therefore, this paper proposes a method to experimentally investigate the influence of the HVAC system on the energy consumption and thermal comfort in a 12m e-bus. An appropriate thermal comfort model is identified and the required climatic input parameters are selected and measured with self-developed sensor stations. The energy consumption of the e-bus, the state of charge (SoC) of the battery and the available travel range are measured by an embedded data logger. Climatic measurements are then performed with heating on and off on a Berlin bus line in winter conditions. The results show that the energy consumption of the e-bus is increased by a factor of 1.9 with heating on, while both the SoC and travel range are reduced accordingly. Comparing the thermal comfort with heating on and off, a decrease from “comfortable” to “slightly uncomfortable but acceptable” is observed.

Development of an indoor environment evaluation model for heating, ventilation and air-conditioning control system of office buildings in subtropical region considering indoor health and thermal comfort

2021 ◽  
pp. 1420326X2110355
Author(s):  
Miaohong Huang ◽  
Yundan Liao
Keyword(s):  
Control System ◽  
Air Quality ◽  
Thermal Comfort ◽  
Air Conditioning ◽  
Indoor Environment ◽  
Comprehensive Evaluation ◽  
Evaluation Model ◽  
Hvac Systems ◽  
Humid Climate ◽  
Weighting Factors

Office occupants spend most of their time in an enclosed indoor environment, controlled by heating, ventilation and air-conditioning (HVAC) systems especially in subtropical regions owing to the hot and humid climate. A reasonable indoor environment evaluation model is necessary to achieve the reliable control of HVAC systems that satisfies the occupants’ health and comfort needs. However, traditional HVAC systems are controlled based on a simple index that does not consider the synthesis of indoor air quality, thermal comfort and occupant preferences. In this paper, we develop a comprehensive evaluation model that encompasses these three aspects based on field survey. Field surveys were conducted to investigate indoor environmental conditions and preferences of the occupants. Collected data were then verified for model hypothesis rationality and reviewed to identify weighting factors using Pearson and regression analysis. Results showed that these parameters had significant correlations without noticeable collinearity and can be integrated using regression method. The weighting factors of each parameter were calculated using occupants’ sensation and expectation to reflect the subjective preferences in model. Finally, an evaluation model expressing the indoor thermal, air quality and occupant preferences was developed to provide an HVAC intelligent control system that is more responsive to occupant needs.

scholarly journals Energy-Saving Potential of Extending Temperature Set-Points in a VRF Air-Conditioned Building

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2160 ◽  
Author(s):  
Joowook Kim ◽  
Doosam Song ◽  
Suyeon Kim ◽  
Sohyun Park ◽  
Youngjin Choi ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Thermal Comfort ◽  
Energy Saving ◽  
Energy Efficient ◽  
Air Conditioning ◽  
Control Strategies ◽  
Hvac Systems ◽  
Set Point ◽  
Energy Saving Potential ◽  
Human Thermal Comfort

Building energy savings and occupant thermal comfort are the main issues in building technology. As such, the development of energy-efficient heating, ventilation, and air-conditioning (HVAC) systems and the control strategies of HVAC systems are emerging as important topics in the HVAC industry. Variable refrigerant flow (VRF) systems have efficient energy performance, so the use of VRF systems in buildings is increasing. However, most studies on VRF systems focus on improving mechanical efficiency, with few studies on energy-efficient control while satisfying the thermal comfort of occupants. The goal is to estimate the energy-saving potential of adjusting the temperature set-points and dead-band (range) in VRF air-conditioned building. To do so, we analyzed the influence of control strategies of a VRF system on human thermal comfort and energy consumption using a simulation method. The results showed that energy consumption can be reduced by 25.4% for predicted mean vote (PMV)-based control and 27.0% for the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) comfort range control compared with the typical set-point temperature control of a VRF system. The indoor thermal environments of the analyzed control strategies are controlled in the thermal comfort range, which is based on a PMV at ±0.5. Compared with the typical set-point control, PMV and ASHRAE comfort range-based control reduced the operation time of the compressor in the VRF system.

scholarly journals Personal Climatization Systems—A Review on Existing and Upcoming Concepts

2018 ◽  
Vol 9 (1) ◽  
pp. 35 ◽  
Author(s):  
Alexander Warthmann ◽  
Daniel Wölki ◽  
Henning Metzmacher ◽  
Christoph van Treeck
Keyword(s):  
Energy Efficiency ◽  
Air Quality ◽  
Thermal Comfort ◽  
Air Temperature ◽  
Air Conditioning ◽  
Environmental Control ◽  
Thermal State ◽  
Comfort Level ◽  
Sensor Data ◽  
Thermal Actuators

To accomplish the current climate goals of the federal republic of Germany, energy efficiency within the building and automotive sector must improve considerably. One possible way to reduce the high amount of energy required for heating, ventilation, and air-conditioning (HVAC) is the introduction of personal climatization systems in combination with the extension of the standardized room air temperature range. Personal systems allow improvements of climatic conditions (heating, cooling, and air quality) within sub-areas of the room instead of conditioning an entire room air volume. In this regard, personal systems are perfectly suitable for locations with local air-conditioning focal points, such as open-plan offices and vehicle cabins, where they substantially improve the energy efficiency of the entire system. This work aims to summarize previously conducted research in the area of personal climatization systems. The investigated local thermal actuators comprise fans for the generation of air movement, ventilators for the improvement of the air quality within the respiratory area of persons, water-conditioned panels for the climatization of persons via longwave radiation and conduction, radiant heaters, and combinations of the systems. Personal systems are superior to mixing ventilation regarding the improvement of the perceived air quality and thermal comfort. Furthermore, the introduced overview shows that personal climatization systems are generally more energy-efficient than conventional air-conditioning and facilitates the extension of the indoor air temperature corridor of the HVAC. Table fans and climatized seats are highly effective in connection with the improvement of personal thermal comfort. The performance of the overwhelming majority of applied personal environmental control systems is user-controlled or depends on a predefined load profile, which is generally defined person independent. Single studies reveal that effectively controlled automated systems have a similar thermal impact on a user’s thermal comfort as user-controlled ones. The implementation of an automated control system is feasible by using novel approaches such as the so-called human-centered closed loop control-platform (HCCLC-platform). The latter contains a central data server which allows asynchronous, bi-directional communication between multi-modal sensor data, user feedback systems, thermal actuators and numerical calculation models used to assess the individual thermal comfort of a person. This enables a continuous and holistic reflection of the thermal situation inside a room and the estimation of the corresponding impact on an individual’s thermal comfort. Considering the measured and simulated thermal state of a single person, the described system is capable of determining body-part-specific energy requirements that are needed to keep the overall thermal comfort level of an individual person on a high level.

Influence of trees on the energy consumption of a social housing in mid-western Brazil

2019 ◽  
pp. 53-65
Author(s):  
Renata Domingos ◽  
Emeli Guarda ◽  
Elaise Gabriel ◽  
João Sanches
Keyword(s):  
Energy Consumption ◽  
Solar Radiation ◽  
Thermal Comfort ◽  
Air Conditioning ◽  
Computational Simulation ◽  
Building Energy ◽  
General Idea ◽  
Heat Island ◽  
Study Region ◽  
Ample Evidence

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.

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

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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