• International Journal of High-Rise Buildings
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• v.8 no.1
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• pp.71-82
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• 2019

The purpose of this study is to evaluate the indoor air quality (IAQ) and energy benefits of a dedicated outdoor air system (DOAS) and compare them with a conventional variable air volume (VAV) system. The DOAS is a decoupled system that supplies only outdoor air, while reducing its consumption using an enthalpy wheel. The VAV system supplies air that is mixed outdoor and transferred indoor. The VAV has the issue of unbalanced ventilation in each room in multiple zones because it supplies mixing air. The DOAS does not have this problem because it supplies only outdoor air. That is, the DOAS is a 100% outdoor air system and the VAV is an air conditioning system. The transient simulations of carbon dioxide concentration and energy consumption were performed using a MATLAB program based on the thermal loads from the model predicted by the TRNSYS 18 program. The results indicated that when the air volume is large, such as in summer, the distribution of air is not appropriate in the VAV system. The DOAS however, supplies the outdoor air stably. Moreover, in terms of annual primary energy consumption, the DOAS consumed approximately 40% less energy than the VAV system.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.393-402
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• 1993

Two field test installations are discussed. In the first one a new ammonia sensor and an accurate ventilation rate sensor are combined. They are installed in the exhaust chimney in a ventilated pig house. The relative humidity and the room temperature are measured as well. In the second one, an in situ NH$_3$longrightarrowNO converter with subsequent NOx analyser is also being added for accurate ammonia measurement . In this way , the continuous measurement of the total NH$_3$emission can be obtained , the performance of the NH$_3$ sensor can be evaluated, and the ammonia reduction techniques can be tested. The outputs of measurement are fed into a data acquisition system then to a PC in the laboratory. There has been realised the first test installation with which research on the new ammonia sensor is carried out. The primary research results are presented.

• Journal of the Korean Solar Energy Society
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• v.27 no.3
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• pp.55-61
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• 2007

This paper has been conducted to estimate cooling capacity of the dehumidification tower using hot water from a solar water heating system as a energy source of regeneration process when the dehumidification and drying system is applied to room cooling. A solar water heating system was operated and indoor temperature distributions were simulated according to weather conditions when the concerned solution was used to dehumidify room air in the dehumidification tower. Through this simulation researches we found th following results ; It was found that air velocity through supply and return diffusers should be controlled because it can cause uncomfort in dwelling area. It was found that in the sunny morning temperatures of dwelling area 1 and 2 are higher than those of dwelling area 3 and 4. In this research all the calculation results of heating and cooling system supported by solar water heater have confirmed that its cooling capacity could not reach PMV 0, thermal comfort.

• Journal of Korean Physical Therapy Science
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• v.9 no.3
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• pp.141-150
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• 2002

Most of physical therapists has thought be exposed themselves to risk of hospital infection but it is reported that have been low concern about infection management. Above like this haven t done systematical education on hospital infection, also physical therapist's information management of infection disease is found very low. It is lack of driving information about disease condition of the patients. Physical therapists has thought their working room may be polluted a lots of micro-organism(%). The control situation of infection waste articles, only 53% responded that the controller has managed very intensive so we can feel to need more intensive It's reported that air culture investigation of physical therapy room has never initiated. To wash the hand, before, after treatment of the patients of physical therapist, is very low frequency. And 73% have responded that the time to wash the hand stays 15-45 second. It is examined that 70% physical therapy room is equipped with washing system, a response of 58% disinfects physical therapy room 1-2times per one month. 36% responded disinfection of treatment modality have done everyday, 25% responded have never done. The location physical therapy room is above one floor - 65%. A response of 57% is ventilation system sufficiency, it is considered that physical therapists needs more efforts on management of hospital infection.

• Land and Housing Review
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• v.14 no.4
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• pp.111-120
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• 2023

Indoor air quality has become increasingly important with the increase in time spent in residential environments, impact of external fine dust, yellow dust, and the post-COVID 19 pandemic. Residential mechanical ventilation plays a key role in addressing indoor air quality. The legal standard for residential air changes per hour in Korea is 0.5 ACH. However, there are no standards for the location of supply and return vents. This study atempts to analyze the impact of ventilation performance based on the location of supply and return vents. An experiment was conducted using the CO₂ tracer gas concentration decay method in a mock-up house set inside a large chamber to minimize external influences. The experimental results indicated that the commonly used combination of 2 supply and 2 return vents in living room spaces had a lower mean age of air than the combination of 1 supply and 2 return vents. Using multiple supply and return vents had lower mean age of air than using just 1 supply and 1 return vent.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.1
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• pp.56-61
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• 2005

Indoor air quality becomes of a concern recently in view of human health. This study investigates the air diffusion performance and the air change efficiency of a classroom, when outdoor air is introduced in addition to the heating/cooling operation of a ceiling-mounted heat pump. A CFD analysis has been performed to investigate the effect of the discharge angle of the air jets from the heat pump for both parallel and series types of outdoor air system. It is observed that the series type creates more uniform indoor environment compared to the parallel type in general. It can be concluded the discharge angle should not be larger than 40o for the parallel type, in order not to generate thermal stratification in the room.

• Journal of the Korean housing association
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• v.16 no.4
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• pp.37-44
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• 2005

The purpose of this study is to analyze the typological characteristics of super high-rise housings in Hong Kong. The results are as follows; 1) Most of the plan types of the residential building in Hong Kong are tower types and they show lots of curves on the external resident blocks so that each resident families can face maximum open air. 2) Each residential unit is arranged symmetrically and systematically around the central core. 3) The most of core types are central core types which are usually planned to place void light well to improve lighting and ventilation. 4) Rooms are arranged in line from entrance to kitchen, to living & dinning room, and finally bedroom and bathroom. Dinning area is arranged together with living area. 5) At least, more than two sides of the each unit were facing the open air; one side is for the view from a bedroom or a livingroom, the other side is for the ventilation of a kitchen or a bathroom.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2009.11a
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• pp.251-256
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• 2009

The purpose of this study was to suggest the idea for IAQ improvement of university dormitory through space analysis and residents' evaluation. The data was collected from 105 Konkuk university dormitory residents by a questionnaire survey. As a result, the idea for IAQ improvement of university dormitory can be suggested. First, it was found that it was necessary to improve size of windows and to exchange bathroom exhaust system for ventilation. Secondly, it is important for resident to ventilate and clean their room. Thirdly, the educational program for dormitory residents about maintenance of IAQ was esssentially needed. Also, it is necessary to manage air conditioning equipment maintenance and bathroom hygiene.

• Journal of environmental and Sanitary engineering
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• v.1 no.1 s.1
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• pp.47-58
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• 1986

The underground living spaces have become one of the major environment of this decade in urban area. This study was carried out to examine contamination level for purpose of preservation of the pleasant underground environment. Three subway stations and three underground shopping centers in Seoul and two underground shopping centers in Busan were selected and surveyed by measuring gaseous pollutants $(SO_2,\; NO_2,\;CO,\;HC,\; HCHO,\;CO_2)$, dust, airborne microbes, and the other air condtions (temperature, humidity, air pressure, air flow, kata cooling power). These examined data were compared with four kinds of standard (building sanitation management, room air quality standards, occupational safety and health standards, ventilation equipment) as environmental hygiene.

• Tunnel and Underground Space
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• v.24 no.6
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• pp.464-472
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• 2014

In large-opening room-and-pillar mining sites, particularly without the devices for the ventilation control, the airflow pattern created by the local fan operation is too complicated to quantify and also shows low ventilation efficiency. This study aims at performing a series of CFD analysis for the so-called venturi effects of the local fans; the effects of increasing airflow rate along the axis downstream of fan resulting from increased kinetic energy and subsequently decreased static pressure in the downstream. Effects of the fan type and installation height are compared. 1 vane-axial fan and 2 propeller fans are analyzed for their venturi effects, while the vane-axial fan was installed at the height of 1.0, 1.5 and 2.0m for comparison. The results can be applied to improve the economy and efficiency of local fans for securing better air quality and work environment management.