• Magazine of the Korean Society of Agricultural Engineers
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• v.33 no.3
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• pp.91-100
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• 1991

Since ventilation in livestock buildings is critical for indoor air quality, the first step in designing environmental control is to determine required ventilation rate. The purpose of the study was to suggest a conceptually new ventilation graph for determining minimum/maximum ventilation rate based on the conservation law of the thermal energy and mass in livestock buildings. PC-based programs coded with PASCAL language, [RVALUE] for overall thermal resistance of composite structural walls/ceilings, [POLYNOM] for coefficients values of animal's sensible heat equation were involved in developing a computer program, [VENTGRPH] for the determination of ventilation rate. It would be useful for design, for such a program would permit the designer to explore various design options and immediately, see the result in terms of its effect on minimum ventilation rates.

• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.116-118
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• 2005

The ASHRAE first ventilation standard was established in 1973. This standard has been revised regularly, and recently the ventilation standard for residential building was issued separately. Two ASHRAE ventilation standards are introduced in this article.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.283-288
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• 2006

Indoor Air Quality Guideline of Kindergarten in korea didn't consider the vulnerable properties of children to indoor air pollutants. For this reason, Suggestion for the IAQ guideline of formaldehyde and minimum ventilation rate was made in this study. Suggested IAQ guidelines for formaldehyde in the respect of children's vulnerable immune system is $30{\mu}g/m^3$ and $50{\mu}g/m^3$, and for the ventilation rate 11.9 ACH, 5.8 ACH, respectively. This value is based only formaldehyde and CO2 concentrations in child-care room of Kindergarten and needed to be verified by further investigations and studies. However it is discovered that lower formaldehyde concentration can do mal-effects to children's health by literature review.

• KIEAE Journal
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• v.9 no.1
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• pp.85-90
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• 2009

The indoor air quality is one of the most important issues of designing ventilation in high rise apartment buildings. This study suggested proper ventilation rate in the apartment bedroom where mechanical ventilation system has installed. Six university students(four male and two female) were participating in the experiment. Experiments were performed in environmental chamber. Experimental conditions were combinations from three ventilation rate 0, 0.4 and 0.7. Measurement items during 8 hours of experimental time were temperature, humidity, carbon dioxide concentrations and questionnaire surveyed aftrer sleeping. The concentration of Carbon Dioxide depending on ventilation rate in the chamber was analyzed for proper ventilation rate. The results of this paper can be summarized as follows. (1) When two persons experiment, 0.7 ventilation rate was in excess of 1000ppm. (2) When one person experiment, 0.7 and 0.4 ventilation rates were satisfied the criteria of IAQ. (3) It compared 0.4 with 0.7 in the ventilation rate, 0.4 ventilation rate could reduced about 80% of the power by fan similarity law.

• International Journal of High-Rise Buildings
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• v.3 no.2
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• pp.155-165
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• 2014

This study measured and compared the variation of ventilation rate and fan energy consumption according to various control strategies after installing wireless sensor-based pilot ventilation system in order to verify the applicability of demand-controlled ventilation (DCV) strategy that was efficient ventilation control strategy for underground parking lot. The underground parking lot pilot ventilation system controlled the ventilation rate by directly or indirectly tracking the traffic load in real-time after sensing data, using vehicle detection sensors and carbon monoxide (CO) and carbon dioxide ($CO_2$) sensor. The ventilation system has operated for 9 hours per a day. It responded real-time data every 10 minutes, providing ventilation rate in conformance with the input traffic load or contaminant level at that time. A ventilation rate of pilot ventilation system can be controlled at 8 levels. The reason is that a ventilation unit consists of 8 high-speed nozzle jet fans. This study proposed vehicle detection sensor based demand-controlled ventilation (VDS-DCV) strategy that would accurately trace direct traffic load and CO sensor based demand-controlled ventilation (CO-DCV) strategy that would indirectly estimate traffic load through the concentration of contaminants. In order to apply DCV strategy based on real-time traffic load, the minimum required ventilation rate per a single vehicle was applied. It was derived through the design ventilation rate and total parking capacity in the underground parking lot. This is because current ventilation standard established per unit floor area or unit volume of the space made it difficult to apply DCV strategy according to the real-time variation of traffic load. According to the results in this study, two DCV strategies in the underground parking lot are considered to be a good alternative approach that satisfies both energy saving and healthy indoor environment in comparison with the conventional control strategies.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.10
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• pp.235-243
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• 2019

In South Korea, millions of poultry have died due to repeated heat waves every year. The purpose of this study is to analyze the characteristics of heating and cooling loads of chicken houses in Korea and to present an effective insulation and ventilation measures to minimize the damage of poultry due to summer heat wave and to save energy in chicken houses in winter. The heating and cooling loads of standard chicken house were calculated. As a result of the calculation of maximum heating load based on the minimum ventilation rate in winter, the outdoor air temperature requiring heating was $6{\sim}7^{\circ}C$ to keep the indoor air temperature of chicken houses as $24^{\circ}C$. The peak cooling load of chicken houses was mostly taken by the heat generated by chickens and the heat gain due to ventilation. The heat gain through building envelopes was as small as neglectable. Most of chicken houses is usually cooled by gigantic forced ventilation in summer in Korea. When the chicken houses are cooled by electric cooling machine such as cooler or air conditioner, it is more effective to keep minimum ventilation rate to reduce the maximum cooling load. To lower the temperature of supplying water to cooling pad, it is recommended to use the underground water below 10 meters from the ground if there is abundant underground water.

• International Journal of High-Rise Buildings
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• v.2 no.4
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• pp.331-340
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• 2013

The main topic of this paper is to show a possibility of indoor air quality enhancement and the fan energy savings in underground parking facilities by applying the demand-controlled ventilation (DCV) strategy based on the real-time variation of the traffic load. The established ventilation rate is estimated by considering the passing distance, CO emission rate, idling time of a vehicle, and the floor area of the parking facility. However, they are hard to be integrated into the real-time DCV control. As a solution to this problem, the minimum ventilation rate per a single vehicle is derived in this research based on the actual ventilation data acquired from several existing underground parking facilities. And then its applicability to the DCV based on the real-time variation of the traffic load is verified by simulating the real-time carbon monoxide concentration variation. The energy saving potentials of the proposed DCV strategy is also checked by comparing it with those for the current underground parking facility ventilation systems found in the open literature.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.517-522
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• 2008

Ventilation rate and filter were selected to simultaneously satisfy indoor air quality and minimize energy consumption in residential housing. The concentrations of indoor particles were calculated using an adapted mass balance model for various ventilation airflow rates. To satisfy the guidelines for indoor concentrations of particles, the minimum ventilation rates of 1.0/h, 0.6/h and 0.4/h were required for MERV11, MERV13 and MERV14, respectively. And the fan power consumptions induced by ducts, a heat exchanger and a filter were calculated for various ventilation airflow rates. The increase in the ventilation rate caused a dramatic increase in the power consumption, but the filter performance did not have much of an effect on the fan power for ventilation airflow rates lower than 0.4/h. The use of the ventilation filter of MERV 14 was suggested at a ventilation rate of 0.4/h when the fan power consumptions were considered in addition to the indoor concentrations of particles and $CO_2$. The use of the MERV14 filter at a ventilation rate of 0.6/h could be more effective than the additional use of an indoor air cleaner when the residential housing unit was ventilated.

• Structural Engineering and Mechanics
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• v.88 no.6
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• pp.521-533
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• 2023

In the present study, the finite volume method is applied for the thermal performance prediction of the natural ventilation system using vertical solar chimney whereas, design parameters are optimized through the response surface methodology (RSM). The computational simulations are performed for various parameters of the solar chimney such as absorber temperature (40≤T_abs≤70℃), inlet temperature (20≤T₀≤30℃), inlet height of (0.1≤h≤0.2 m) and chimney width (0.1≤d≤0.2 m). Analysis of variance (ANOVA) was carried out to identify the design parameters that influence the average Nusselt number (Nu) and mass flow rate (ṁ). Then, quadratic polynomial regression models were developed to predict of all the response parameters. Consequently, numerical and graphical optimizations were performed to achieve multi-objective optimization for the desired criteria. According to the desirability function approach, it can be seen that the optimum objective functions are Nu=25.67 and ṁ=24.68 kg/h·m, corresponding to design parameters h=0.18 m, d=0.2 m, T_abs=46.81℃ and T₀=20℃. The optimal ventilation flow rate is enhanced by about 96.65% compared to the minimum ventilation rate, while solar energy consumption is reduced by 49.54% compared to the maximum ventilation rate.

• Journal of Animal Environmental Science
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• v.2 no.2
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• pp.103-110
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• 1996

This survey was conducted to investigate the situation of three types of laying hen houses and farmers' awareness of farm automation. Six windowless, three high-rising windowless and four open-sided laying hen houses were surveyed to compare their characteristics, and sixty farmers answered questionnaires. 1. Population density of laying hen was 13.9 birds/m^2$ in open-sided, 28.9 birds/m^2$ in high-rising windowless, and 44.9 birds/m^2$ in windowless laying hen houses. 2. Feeder space was $12{\sim}13.5cm$ in open-sided laying hen houses, but feeder space of windowless and high-rising hen houses was narrower than that of open-sided laying hen houses. 3. Thermal resistance values were $14.6{\sim}18.7\;m^2\;{\circ}C/W$ in wall, #22.0{\sim}23.7\;m^2\;{\circ}C/W$ in roof of windowless and high-rising windowless laying hen houses but the wall of open-sided laying hen houses was only $1.9\;m^2\;{\circ}C/W$. 4. Maximum ventilation capacity was 0.161{\sim}0.326$ cmm/bird in summer. Minimum rate of tunnel Ventilation laying hen houses in winter was $0.013{\sim}0.040$ cmm/bird, but minimum rate of crossflow and high-rising windowless laying hen houses was larger than that of tunnel ventilation houses. 5. One person managed about 8,100 birds in open-sided, and about 23,500 birds in windowless and high-rising windowless laying hen houses. 7. 90.7% of farmers responsed that they want to construct automatized laying hen houses in the future.