• Proceedings of the SAREK Conference
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• 2007.11a
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• pp.346-351
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• 2007

Dedicated outdoor air(DOA) system which conditions the outdoor air separately is superior to conventional cooling+reheating system with respect to energy consumption and indoor comfort. Since the sensible and latent load characteristics of indoor and outdoor are different, it is more efficient to treat them separately. In this study, cycle analysis and on-site performance test of DOA system have been conducted. The study shows that DOA requires 48.8% less equivalent energy that conventional system. The on-site performance test of the prototype shows that the coefficient of performance(COP) of the DOA system is 37.4% higher than the conventional system.

• Korean journal of food and cookery science
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• v.13 no.5
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• pp.592-601
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• 1997

The purposes of this study were to develop Hazard Analysis Critical Control Point-based standardized recipe applicable to cook/chilled soy sauceglazed mackerel and to evaluate the qualities related to the product flow of this item. After conducting experimental cooking, preliminary test, and analysis of recipes, critical control points were identified, control methods were determined, and HACCP-based recipe was standardized. At each critical control point, time-temperature profile was recorded and microbiological analysis (total aerobic plate counts, psychrotrophic plate count, coliform, and fecal coliform count), chemical analysis (pH, acid value and volatile based nitrogen (VBN)) and sensory evaluation of the item were done. Time-temperature data showed that the time the menu item had passed through temperature danger zone (5∼60$^{\circ}C$) during all phases was 60 min. At rapid cooling, but after cooling at room temperature, the temperature of this menu item did not drop below the ambient temperature. The results of microbiological test were negative throughout all phases following cooking and the results of chemical analysis did not change significantly in terms of storage periods except for VBN which increased on 7th day significantly(p<0.05). After steam/convection oven reheating and microwave oven reheating, the sensory score of the only appearance decreased significantly related to the storage time of overall quality profiles. But significant differences were not detected according to two reheating methods. In conclusion, this HACCP-based recipe was considered as an effective tool for assuring microbial as well as sensory quality of this cook/chilled item.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.5
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• pp.273-281
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• 2009

In recent semiconductor manufacturing clean rooms, the energy consumption of outdoor air conditioning systems represents about 45% of the total air conditioning load required to maintain a clean room environment. Meanwhile, there is a large amount of exhaust air from a clean room. From an energy conservation point of view, heat recovery from the exhaust air is therefore useful for reducing the outdoor air conditioning load for a clean room. In the present work, an energy-efficient outdoor air conditioning system was proposed to reduce the outdoor air conditioning load by utilizing an air washer to recover heat from the exhaust air. The proposed outdoor air conditioning system consisted mainly of a preheating coil, an air washer, two stage cooling coils, a reheating coil, a humidifier and two heat recovery cooling coils inserted into the air washer and connected to a wet scrubber. It was shown from the lab-scale experiment with outdoor air flow of $1,000\;m^3/h$ that the proposed system was more energy-efficient for the summer and winter operations than an outdoor air conditioning system with a simple air washer.

• Korean journal of food and cookery science
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• v.2 no.2
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• pp.21-31
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• 1986

Here is a research on hospital foodservice system, when korea traditional food of pyeon yuk and bin dae deok were used by ready-prepared foodservice system, it was estimated the preservations of microbiological quality and sensory quality. All data collection was replicated three times. The results were as following; 1. In time and temperature data, two menu items were needed internal temperature below $7^{\circ}C$ in a cooling stage, and in the case of cook/chill storage, the days were shortened within weeks, and the holding time must be possiblely minimized. Finally foods were served sanitary. 2. In view of microbiological safety, in the case of cook/chill storage as $0{\sim}4^{\circ}C$ the days must be shortened within 2 weeks and its was possible to store until 6 weeks in $-20{\sim}-23.3^{\circ}C$. So to preserve pre-cooked food longly, it was effective to freeze them quickly by using vacuum package and to reheat them by a microwave oven before serving and to serve lastly in microbiological quality. 3. Hospital ready-prepared foodservice system with food storage in plastic bags, biochemical test of C. Perfingens C. botulinum and Salmonella were not detected. 4. By using of a microwave oven, it had effects of thawing, reheating and sterilizing of chilled and frozen foods in a short time. 5. Sensory evaluations were made by a 10-member panel using five scoring tests. Because sensory of quality was lowered in the case of chilled storage, it was possible to serve foods within 2 weeks. Texture and aroma were preserved by cook/frozen system and usually there was no significance from 4 weeks until 6 weeks, but considering of the objects, it was good to store until 4 weeks in sensory quality.