• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.12
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• pp.857-864
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• 2007

In the current residential building, hot water supply system consumes the second largest energy in order to make the thermal comport condition of residential space. The more residential environment improves the more the demand for hot water and water consumption is increasing gradually. So this study examines the possibility of applying the recirculation for individual hot water supply system compared with the existing method for waiting time for hot water, wasted water and energy consumption. The results are as follows. (1) In case of recirculation system method the waiting time for hot water can be reduced up to $69\sim85%$ in spring and fall period and so dose up to $77\sim85%$ in winter period. (2) The total wasted water has a little change compared with the existing method which can make the total wasted water reduced about $77\sim86%$. (3) The efficiency of hot water supply system can be improved, if the method which blocks the inflow of cold water is applied, when return pump is operated to recirculate hot water in recirculation system.

• Journal of Environmental Health Sciences
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• v.14 no.1
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• pp.23-32
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• 1988

A study was carried out to find distribution of Legionella spp. in hot water supplying systems of buildings in Seoul. Water samples were taken from the hot water taps in three research institute buildings during the period from the 2nd to 27th February, 1987. And all of the three buildings were supplied with hot water from the same central hot water tank. GVPC BCYEa and blood agar were used for the isolation of Legionella pneurnophila and slide agglutination test (SAT) was performed to identify their strain types. Main findings were as follows 1. 44 samples taken from hot tap-water revealed 20% of positive culture and 44 samples taken from hot water spouts revealed 11% of positive culture. 2. The 78% of positive samples taken from hot water was obtained from 25.1$\circ$C~45.0$\circ$C temperature range. 3. Only, Legionella pneumophila serogroup 3 was identified and most of them has been than 2$\mu$m in length. 4. The densities of the Legionella pneurnophila isolated from hot water samples were within the range of $1.0\times 10^2$ to $1.1\times 10^3$ CFU/l and their densities isolated from hot water spouts were either 1 CFU/plate or 2 CFU/plate.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.7
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• pp.609-614
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• 2002

In this study, we investigated the effects of hot water on the aging of URD power cables due to the hot water ingress to power distribution lines. Hot water contacted and non-contacted cables extracted from 2 distribution lines were characterized by the measurement of oxidation induction time(OIT) and chemical structure. In OIT measurement, hot water contacted cables showed the shorter OIT than non-contacted ones. Especially, hot water contacted insulation layer near insulation shield showed the shortest OIT. In chemical structure analysis, the antioxidant content was decreased and the acid concentration was increased by hot water ingress. From this results, it can be concluded that the hot water ingress to power cable may be accelerate the aging by means of antioxidant consumption.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.6
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• pp.758-765
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• 1999

The estimation of reasonable amount of domestic cold water and hot water supplies in apartment houses is very important for the economical design of domestic cold water and hot water supply system which include pumps, boilers, heat exchangers, and various water reservoirs. To suggest the model of predicting reasonable amount of domestic cold water and hot water supplies, residents and actual domestic cold water and hot water consumption have been investigated for 740 apartment houses in Seoul and Bun-Dang, Kyunggi-Do. The model is suggested as a function of exclusive area of the apartment house and results of the model show generally good agreement with published data.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.266-269
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• 2009

The Purpose of this study was thermal performance of solar hot water and space heating thermal storage tank. The combi storage tank was designed Tank in Tank type. The tank volume for space heating was 700 $\ell $ and tank volume for hot water was 150 $\ell $. Tank in Tank type storage tank was to replace heat exchange to hot water tank. The result showed that the Heating value was 67.25MJ and domestic hot water value was 51.93MJ. Supply to the hot water volume was 521 $\ell $ more than about 3 times as that of the hot water tank volume.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.15 no.4
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• pp.32-38
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• 2019

In this study, the effect of hot water supply flow rates on energy consumption for radiant floor heating system in apartment were researched by computer simulation. The parametric study of different hot water supply flow rates was done with regard to energy performance and control characteristics, respectively. Also the effect of different hot water supply flow rates on the hot water supply temperatures is studied. As a result, energy consumption were reduced but the response time is increased by reducing the supply flow rate. And energy consumption can be saved by adjusting the hot water supply temperatures with different supply flow rates.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.9
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• pp.355-360
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• 2016

Continuing to the modeling of heating load, this paper, as the second part of consecutive works, presents LS-SVM (least square support vector machine) based model of winter time apartment hot water supply load in a district heating system, so as to be used in prediction of heating energy usage. Similar, but more severely, to heating load, hot water supply load varies in highly nonlinear manner. Such nonlinearity makes analytical model of it hardly exist in the literatures. LS-SVM is known as a good modeling tool for the system, especially for the nonlinear system depended by many independent factors. We collect 26,208 data of hot water supply load over a 13-week period in winter time, from 12 heat exchangers in seven different apartments. Then part of the collected data were used to construct LS-SVM based model and the rest of those were used to test the formed model accuracy. In modeling, we first constructed the model of district heating system's hot water supply load, using the unit heating area's hot water supply load of seven apartments. Such model will be used to estimate the total hot water supply load of which the district heating system needs to provide. Then the individual apartment hot water supply load model is also formed, which can be used to predict and to control the energy consumption of the individual apartment. The results obtained show that the total hot water supply load, which will be provided by the district heating system in winter time, can be predicted within 10% in MAPE (mean absolute percentage error). Also the individual apartment models can predict the individual apartment energy consumption for hot water supply load within 10% ~ 20% in MAPE.

• Korean journal of food and cookery science
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• v.28 no.5
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• pp.569-577
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• 2012

The physicochemical characteristics and biological activities, including antioxidant activity, antimutagenicity, and cytotoxicity of hot-water extract of fruiting body of Hericium erinaceus, were investigated in this study. Hot-water extract of fruiting body of Hericium erinaceus contained carbohydrate (7.86%), protein (10.91%), and ${\beta}$-glucan (3.62%). Water solubility of hot-water extract was 42.58%. Antioxidant activities of the extract were evaluated by ABTS assay and FRAP assay. The $IC_{50}$ value was 312.21 ${\mu}g/mL$ in ABTS assay. Antimutagenic activity of the extract was evaluated by Ames test. Antimutagenicity of hot-water extract (5 mg/mL) on Salmonella Typhimurium TA100 mutagenated by sodium azide (0.15 ${\mu}g/mg$) was 69.2%. Cytotoxicity of hot-water extract was also evaluated by MTT and SRB assay. The cytotoxicity was highest (83.95%) on Hep3B treated with 2,000 ${\mu}g/mL$ of hot-water extract in SRB assay. Therefore, it is suggested that hot-water extract of fruiting body of Hericium erinaceus has high antioxidant activity, antimutagenicity, and cytotoxicity.

• Journal of Oriental Neuropsychiatry
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• v.19 no.3
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• pp.85-100
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• 2008

Objective: This experiment was designed to investigate the effect of the KSKH hot water extract & ultra-fine powder on microglia and memory deficit model. Method: The effects of the KSKH hot water extract on expression of IL-1$\beta$, IL-6, TNF-$\alpha$ mRNA and production of IL-1$\beta$, IL-6, TNF-$\alpha$ in BV2 microglial cell line treated by lipopolysacchaide(LPS) were investigated. The effects of the KSKH hot water extract & ultra-fine-fine powder on the behavior of the memory deficit mice induced by scopolamine and AChE in serum of the memory deficit mice induced by scopolamine were investigated. Results: 1. The KSKH hot water extract suppressed the expression of IL-1$\beta$, IL-6, TNF-$\alpha$ mRNA in BV2 microglial cell line treated by LPS. 2. The KSKH hot water extract suppressed the production of IL-1$\beta$, IL-6, TNF-$\alpha$ in 100$\mu g/m\ell$ concentration of BV2 microglial cell line culture supernatant. 3. The KSKH hot water extract & ultra-fine powder decreased AChE activation significantly in the serum of the memory deficit mice induced by scopolamine. 4. The KSKH hot water extract & ultra-fine powder showed significant effect on memory impairment in the stop-through latency type of Morris water maze test. Conclusions: This experiment shows that the KSKH hot water extract & ultra-fine powder might be effective for the prevention and treatment of amnesia and Alzheimer's disease. Investigation into the clinical use of the KSKH hot water extract & ultra-fine powder for amnesia and Alzheimer's disease is suggested for future research.

• The Korean Journal of Community Living Science
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• v.16 no.3
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• pp.127-132
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• 2005

The aim of this study is to investigate the effects of hot water soluble extract from Angelicae Radix on the components of serum and liver and the effects on the antioxidant system. For this purpose, five experimental groups were set up. And for fat source, perila oil enough with unsaturated fatty acid and beef tallow enough with saturated fatty acid were supplemented to the rats together with hot water soluble extract from Angelicae Radixs. Five experimental groups kept eight Sprague-Dawley rats respectively. They were CO group supplemented with basic diet of AIN-93, PO group supplemented with perila oil, POA group supplemented with perila oil and hot water soluble extract from Angelicae Radix, BT group supplemented with beef tallow, and BTA group supplemented with beef tallow and hot water soluble extract from Angelicae Radix. The results were; 1) Final weight, weight gain, fluid intake and FER were not different significantly among the experimental groups, 2) Significant difference of food intake was observed(p<0.05) in BTA group only, 3) No significant difference was observed in serum total lipid, serum triglyceride and HDL cholesterol among experimental groups. Serum total cholesterol and LDL cholesterol were significantly low(p<0.05) in the group supplemented with beef tallow which was with hot water soluble extract from Angelicae Radix (BTA group). 4)Liver total cholesterol in liver was low in groups supplemented with perila oil and hot water soluble extract from Angelicae Radix. In summary, hot water soluble extract from Angelicae Radix did not affect the weight gain, fluid intake and food efficiency ratio among the experimental groups, but had an effect of lowering food intake, serum total cholesterol and serum LDL cholesterol significantly in the groups which were supplemented with beef tallow and hot water soluble extract from Angelicae Radix. The effect of lowering liver total cholesterol with the supplementation of hot water soluble extract from AnRelicae Radix was observed in perila oil group only. The effect of lowering cholesterol with the supplementation of hot water soluble extract from Angelicae Radix was observed both in serum and in liver.