• Journal of Power System Engineering
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• v.21 no.4
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• pp.84-93
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• 2017

This study was carried out to improve the electric power consumption of HVAC in the blow mold machine(BMM) and work environment. The experiment was conducted with the simulated HVAC system of 1/15 of the actual BMM. The temperature of main facility and two preheaters was fixed at 200 and $60^{\circ}C$ respectively in all test conditions. The measured points of temperature were chosen as critical locations considering the work environment. The tendency of temperature distributions decreases as the duct was closed to the main facility. The reduction rate of power consumption of HVAC increases up to 32.3% when both duct and cooling systems are operated. Also the efficiency of HVAC is improved about 9% through the modified design of duct system. It notes that the electric power consumption of HVAC can be reduced by the optimum design and operating condition of duct and cooling system.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.1081-1082
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• 2008

This paper presents adaptive fuzzy control based on observer for nonlinear HVAC system whose states are not available. Fuzzy systems are employed to approximate the unknown nonlinear functions of the HVAC system and the state observer is designed for estimating the states of the HVAC system. An adaptive fuzzy controller is firstly constructed without the controller singularity problem. The obtained control system shows robustness and effectiveness compared with classical feedback controller. Simulation results are provided to illustrate the control performance.

• International Journal of Internet, Broadcasting and Communication
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• v.8 no.1
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• pp.19-26
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• 2016

In this paper, the existing domestic HVAC systems, devices TCP / IP does not support the most, thereby, not performed remote management, it is necessary to regularly field service, inefficiency and cost bring a burden. This is through a comparison of the IoT-based primary, real-time protocol of what has become a hot topic recently, to be able to control and real-time monitoring through the CCU device in the HVAC system. Compare for this Internet of Things device for real-time monitoring and control of the XMPP, CoAP, MQTT main real-time protocol is used on. Finally, flexibility, light weight, based on MQTT a two-way messaging protocols with reliable message delivery, implements the protocol on the real-time HVAC system in the cloud platform.

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.379-387
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• 1998

HVAC systems are used to maintain comfort conditions in occupied spaces. Like rolling noise and aerodynamic noise, noise from the HVAC system of train increases interior noise level. For an appropriate interior noise level, it is necessary not to find noise sources and their propagation paths. Noise emission from the sources and propagation through the propagation paths should be regulated in order to reduce their effect to the interior noise level. In general, the main noise source in the HVAC system is blower which operates at high static pressure. This noise propagates through ducts which are directly connected to the residential area. Since the blower noise can be reduced only to some degree, it is necessary for the propagation paths to have enough noise attenuation. Acoustic properties of ducts are usually found by experimental methods but it is rather difficult and expensive to set up such test equipments. In this thesis, the design and the noise characteristics of TGV-K HVAC system are studied. Finite element method in accordance with experimental method is used to study the acoustic properties of TGV-K duct system.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.481-486
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• 2008

The building HVAC systems have very different qualities of performance and durability with the superintendent's ability for management and maintenance. The poor management of these systems finally lead to the shortening of the life expectancy and result in the increase of operating costs and energy consumptions due to low efficiencies. So it is essential to try to develop ways to adequately maintain and to use the building facilities efficiently in order to preserve earth environment and the limited resource. In this study, the LCC based numerical calculation package will be developed for the efficient maintenance plan and the determination of the reasonable time of repair or replacement of equipments.

• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.263-268
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• 2009

The current focus of domestic car industry is moving from technological development to reducing greenhouse gas. This study investigates and measures the HVAC system and indoor air condition of highway buses, which is conducted to develop a HVAC system using natural energy in the future. The measurements show that thermal balance is not fulfilled because heating sources are randomly placed, and relative humidity is in the 20 percent range both in HVAC and non-HVAC systems, which is far below 40%, or the highest thermal comfort level. CO2 concentration was found to be an average of 1500 ppm, but not more than 2522 ppm with 15 persons on board, and with 29 persons on board, an average of 2053 ppm, but not more than 3066 ppm, both of which far exceed allowed CO2 concentration level, or 1000 ppm. Generally, highway buses drop by rest stops and open doors for 15 to 20 minutes for getting in fresh air. But its air improvement effect is temporary, and it exacerbates indoor air condition.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.19 no.2
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• pp.67-81
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• 1990

The objective of this is to develop a practical software package to calculate annual energy consumption of HVAC (Heating Ventilating, and Air Conditioning) System in a building. It can quickly estimate loads and energy consumption, and have a function of economic analysis through the estimation of operating cost. Techniques of save energy consumption used in a building are necessary from the stage of design process to operation. The single most significant task is on HVAC Systems. Their installation costs, and related operating costs have enormous influence upon initial and maintenance costs. HVAC designers and engineers now have a wide variety of software choices available, but only a few of them have been developed in this country and no source program has been disclosed. Neither load culculation nor estimation of energy consumption is systematically made by the domestic HVAC design firms. Even though computer improved over the years with a trend of large scale load calculation and system selection through simulaion, the utilization of software nowadays does not make good progress due to lack of working environment. Therefore, it is necessary to develop a practical software package with which load calculation can be made with ease and kind manner. This study concerns the development of a software package which makes it possible to design HVAC system and save energy consumption in operation. The algorithm used in this program is a Modified Bin Method widely known as a simplified energy analysis means.

• Journal of the Korean Institute of Gas
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• v.24 no.1
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• pp.33-40
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• 2020

Chiller systems which have better temperature stability than Direction expansion coils are often used as condensing units in HVAC systems for offshore plants. Large capacity compressors and electronic expansion valves in chiller systems are mostly imported, and the size of a chiller system depends on heat exchangers such as evaporators and condensers which are locally produced. Due to limited space in the offshore plants, shipyards are demanding manufacturers to make equipment compact. In this paper, a shell & tube heat exchanger, which is used as an evaporator in the conventional flooded chiller system, is replaced by a newly developed compact plate & shell heat exchanger. The main development process of the plate & shell heat exchanger is introduced, and its performances were experimentally evaluated with a real flooded chiller system, and the results are presented.

• Fire Science and Engineering
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• v.18 no.4
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• pp.78-85
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• 2004

This research analyzes Clean Room accidents, and presents research Clean Room, major fire prevention standards of Clean Room (FM, IRI, and NFPA Code), various results from Fire Simulation of analysis. The results are : the smoke diffusion is very quick coupled with the Heating, Ventilating, and Air Conditioning (HVAC) systems under fire ; the possibility of getting the result and the possibility the role of the Sprinkler systems to reduce the diffusion of the smoke. We learn about the importance to stop operating Heating, Ventilating, and Air Conditioning (HVAC) systems and to operate the Sprinkler system for securing safety with fire detection. Therefore, This research will be contributing to secure safety of Clean Room.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.54-59
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• 2008

The poor maintenance and management of HVAC systems finally lead to the shortening of the life expectancy and result in the increase of operating costs and energy consumptions due to low efficiencies. Also, it is essential to try to develop ways to adequately maintain and to use the building facilities efficiently in order to preserve earth environment and the limited resource. In this study, an analysis on the maintenance and management cost for HVAC systems was carried out with the capacity of equipment. Besides, the LCC(Life Cycle Cost) based analysis was carried out to verify the effect of the doing maintenance and management. As the results, the case of the good maintenance and management is able to save LCC to 11 % than the case of the poor method.