• Proceedings of the KIEE Conference
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• summer
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• pp.82-84
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• 2004

This paper has calculated DSM's latent capacity through a survey investigating electric arc furnaces in over 2,000 toe companies and related organizations. The latent capacity of DSM calculated with the same time load factor is considered in this paper. The time load factor depends on the probability of each electric arc furnace of the value to work and the consideration of experts and technician's experience. Also, this paper verifies the reliability and application of unposed capacity which compared the old latent capacity of Load Management with KEMCO and KEPCO's Direct Load Control gathering capacity.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.1
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• pp.15-20
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• 2017

The summer climate is very hot and humid in Korea. The humidity is an important factor in determining thermal comfort. Recently, the research for dehumidification device development has been attempted to save energy that is required for the operation of the current dehumidifiers on the market. Existing dehumidification systems have disadvantages such as wasting energy to drive a compressor. Meanwhile, dehumidification systems with membranes can dehumidify humid air without increasing the dry bulb temperature so it doesn't have to consume cooling energy. In this paper, the cooling energy savings was studied when a dehumidification system was applied in a model building instead of a chiller. The sensible heat load was almost the same result, but the latent heat load was decreased by 38.9% and the total heat load was decreased by 8.5%. As a result, electric energy used to drive the compressor in a chiller was saved by applying a membrane air-conditioning system instead.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.2
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• pp.128-136
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• 2008

It is necessary to estimate the cooling load of the next day for effective control of ice thermal storage system. In this paper, new methodology is proposed to estimate the cooling load using design parameters of building and predicted weather data. Only six input parameters such as sensible heat coefficient and constant, latent heat coefficient and constant, maximum and minimum temperature are necessary to obtain hourly distribution of cooling load for the next day. Two benchmarking buildings(hospital and research institute) are selected to validate the performance of the proposed method, and the estimated cooling loads in hourly and daily bases are calculated and compared with the measured data for E hospital. The estimated results show fairly good agreement with the measured data for both buildings.

• Journal of the Korean Society of Industry Convergence
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• v.7 no.4
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• pp.331-340
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• 2004

This paper presents a feasibility study of a fresh air load reduction system by using an underground double floor space. The fresh air is introduced into the double slab space and passes through the opening bored into the footing beam. The air is cooled by the heat exchange with the inside surface of the double slab space in summer, and heated in winter. This system not only reduces sensible heat load of the fresh air by heat exchange with earth but also reduces latent heat load of the fresh air by ad/de-sorption of underground double slab concrete. In this paper, we used a model for evaluation of fresh air latent heat load reduction by hygroscopic of air to earth exchange system taking into account coupled heat and moisture transfer of underground double floor space. In conclusion it shows the validity of the proposed method for a design tool and the quantitative effect of the system.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.2
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• pp.137-143
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• 2003

In the forming of an integrated system of radiant floor cooling and dehumidifying, chilled coil can be used for cooling and dehumidification. Therefore, it is necessary to find the efficient control method which can eliminates latent load efficiently. This study has been conducted to find this method by dividing the dehumidification system into 3 types according to the control variables and analyzing characteristics of each system. To prevent the floor surface condensation, the amount of condensation can be manipulated by water temperatures, water flow rates in chilled coil, and air flow rates passing by it. So dehumidification system control can be divided into constant air flow control and variable air flow control. Regarding dehumidification control, variable air flow control, which eliminates latent load rather than sensible load, is preferable to constant flow control.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.12
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• pp.1057-1065
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• 2000

A sizing of sensible and latent energy recovery system with condensing heat exchanger is important to the design of a thermally controlled facilities. The transient system simulation program TRNSYS 14.2/IISiBat has been used to evaluate the energy consumptions of a thermally controlled facilities which consist of boiler, chiller and condensing heat exchanger, The boiler and chiller are selected based on the annual peak loads and controlled to maintain the setting temperature of $14~17^{\circ}C$. Simulation shows that the amount of sensible and latent energy recovered by heat exchanger is almost 20% of total heating load.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.7 no.1
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• pp.45-50
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• 2011

Hybrid desiccant cooling system(HDCS) consists of desiccant rotor, regenerative evaporative cooler, heat pump and district heating hot water coil. In this study, TRNSYS and EES, dynamic and steady simulation programs were used for studying hybrid desiccant cooling system which is applied to an apartment house from June to August. The results show that power consumption of the hybrid desiccant cooling system is 70 kWh in June, 199 kWh in July and 241 kWh in August. Sensible and latent heats removed by the hybrid desiccant cooling system are 300 kWh, 301 kWh in June, 610 kWh, 858 kWh in July and 719 kWh, 1010 kWh in August. COP of the hybrid desiccant cooling system is 8.6 in June, 7.4 in July and 7.2 in August. COP of the hybrid desiccant cooling system decreases when latent heat load increases. Operation time of the system is 70 hours in June, 190 hours in July and 229 hours in August. Since the cooling load is largest in August, the operation time of August is longest for maintaining the indoor temperature at $26^{\circ}C$. Due to the characteristics of hybrid desiccant cooling system for efficiently handling both sensible and latent loads, this system can handle sensible and latent heat loads efficiently in summer.

• International Journal of Air-Conditioning and Refrigeration
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• v.9 no.4
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• pp.17-26
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• 2001

Simulation was conducted using TRNSYS to evaluate the thermal performance of a facility. This facility has a condensing-type heat exchanger which is able to recover the latent energy for the purpose of reducing the heating energy in winter. The boiler and chiller are selected based on the annual peak loads and controlled to maintain the facility at the set temperature of 14~$17^\circ{C}$. Supplied energy by the boiler and recovered energy by the heat exchanger were calculated as a function of number of pass through heat exchanger, kind of fuel and hot water velocity. Simulation results show that about 20% of the total heating load can be recovered by the heat exchanger and the amount of latent heat is increasing with the number of pass. This means that the efficiency of the waste energy recovery system can be increased by using a condensing-type heat exchanger rather than a traditional sensible heat exchanger.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.7
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• pp.845-852
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• 2003

Liquid desiccant dehumidification system can be used effectively to save energy consumed in air conditioning as an alternative compared with conventional air conditioning systems by reducing latent heat load. The dehumidifier and the regenerator from the heart of this system. The latent part of the cooling load is handled using liquid desiccant. In this study, the experimental regenerator has been designed to study the regeneration characteristics of the aqueous triethylene glycol(TEG) system. The performance factors of the regenerator with finned tube heat exchanger were evaluated by a series of experimental runs. The regeneration process is highly dependent on the liquid desiccant conditions, such as, temperature, concentration and flow rate. In addition, the effects of the inlet air temperature, humidity and flow rate were discussed. Data obtained are useful for design guidance and performance analysis of a regenerator, particularly for a liquid desiccant cooling system.

• Physical Therapy Korea
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• v.18 no.2
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• pp.76-83
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• 2011

The aim of this study was to determine the immediate effects of single treatment of strain-counter strain (SCS) on pressure pain threshold (PPT) and muscle activity during scapular plane abduction with 3% body weight load. Fifteen asymptomatic male adults with upper trapezius latent trigger point (LTrP) (PPT<2.9 $kg/cm^2$) participated in this study. Pressure algometer was used to measure PPT and surface electromyography was used to record upper, middle arid lower trapezius, serratus anterior, infraspinatus and middle deltoid muscle activity and relative ratio during scapular plane abduction between pre- and post-intervention. There was a significant increase in upper trapezius PPT after a 90-second SCS (p<.05). The activity of the upper trapezius and middle deltoid was significantly decreased (p=.014, p=.001), coupled with a decreased muscle activity ratio between the upper and lower trapezius (p<.05). These results indicate that the SCS may effectively deactivate upper trapezius activity, thereby alleviating muscle balance and reducing pain sensitivity.