• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.2
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• pp.100-106
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• 2008

An experimental study was carried out in a small-scale test furnace to investigate the performance, such as $NO_X$ emission, enhancement of heat transfer, uniformity of temperature, and etc, of oscillating combustion applied in radiant tube burner system. A premixed type burner and a cyclic oscillating control valve were designed and used. The fuel, used commercial LPG in this study, was only oscillated using the cyclic oscillating control valve. As oscillating combustion was applied in radiant tube burner system, it is found that $NO_X$ emission, compared to no oscillation, could be reduced by 38% at $90{\sim}120rpm\;(1.5{\sim}2.0Hz)$. However, as oscillating frequency was increased, effect of abatement of $NO_X$ emission is gradually reduced. From the measurement of furnace heating time from $100^{\circ}C$ to $720^{\circ}C$, heat transfer is increased by 11.5% at the oscillation of 120rpm. Temperature distribution of radiant tube surface is more uniform at oscillation of 120rpm with decrease of the peak temperature and increase of low temperature. From these results, it is confirmed that oscillating combustion is useful in radiant tube burner system.

• Journal of the Korean housing association
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• v.15 no.3
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• pp.73-82
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• 2004

The objective of this study is to demonstrate the potential of radiant cooling systems using Ondol as an alternative cooling system in residential buildings. For this purpose, computer simulation and model experiments have been performed for the system performance analysis regarding comfort, floor surface condensation, and supply water temperature. The results of this study is the following: In radiant floor cooling system, room air temperatures were maintained within the set temperature range of $\pm$1$^{\circ}C$ without any discomfort condition. And taking into account only the condensation occurrence, it was possible to achieve radiant floor cooling for a period of about 77% of the total cooling period in weather condition of Seoul. The minimum supply water temperature is about 15$^{\circ}C$, so renewable energy system such as ground heat exchange system can be used as an alternative in cooling source. Also, floor surface condensation can be prevented by integrating with the dehumidification system.

• Journal of the Korean Solar Energy Society
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• v.28 no.5
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• pp.49-55
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• 2008

The radiant cooling(RC) effects are studied during the winter night. The plate was viewing the nighttime sky. The data were collected at the rooftop of the Engineering building at the Dongguk University in Seoul, Korea. As observed during the summer night, the plate temperature was lower than ambient temperature under the RC favorable conditions. The parameters under study are the wind velocity, cloud index, and visibility for given system size and surface condition. The results follow the same tendency with these parameters as observed from the previous study for the summer night. As long as the wind velocity is less than around 2 m/s, the radiant cooling was observed with the system under study. In some cases, the radiant cooling temperature differences (RCTD) are higher than those for the summer night. The larger the RCTD as the wind velocity decreases and as the sky becomes clear.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.9 no.2
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• pp.180-188
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• 1997

The theoretical analysis and experiment with simulator were performed to obtain the temperature distributions in radiant heating panel and heat supply from hot water to heating space for the purpose of the development of comfortable living space from a point of view of the improvement of air quality and the enhancement of system efficiency. The relations of various parameters, such as pipe pitch, room temperature as well as flow rate and temperature of hot water and so on, with the rate of heat supplied, mean temperature and maximum temperature difference at panel surface were discussed. The effects of these parameters were also verified on the thermal performance of heating panel using the relations which could be used for the optimal design and operation of the radiant heating panel.

• Journal of the Korean housing association
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• v.15 no.2
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• pp.107-115
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• 2004

The objective of this study is to show the system Integrations and control method for operation of the Radiant Floor Cooling. The systems for radiant floor cooling system consist of only using the radiant floor cooling and the radiant floor cooling integrated with a dehumidification system. And the study is suggested control method with composed radiant floor cooling system through simulations. Radiant floor cooling systems compose of four main parts: an existing radiant heating panel, manifold, cooling source and controller, and sensors. If dehumidifying or supplementary cooling is needed, additional equipments such as PAC and AHU are needed. Simulation results show that control method only using radiant floor cooling system can prevent condensation and set room air temperature with the exception of hot and humid periods and control method using the radiant floor cooling integrated with a dehumidification system is comfort thermal environments and can reduce the cooling load quickly, moreover, show comfort control method to meet various cooling operation situations.

• Journal of the Korean Home Economics Association
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• v.24 no.2
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• pp.75-82
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• 1986

This study was measured experimentally the Configuration factor of the adult female with the purpose of explaning quantitatively the human body's radiant heat exchange in a small scale of a house. And it is a investigatio about human clothed body's heat resistance which have great influence on radiant heat exchange. The result of this study was diagrammatized the [Shape×Area Factor] for the sake of making it easy to calculate the quantity of the actual human body's radiant heat exchange, and designed a diagram to make it easy to find the value of the human clothed body's heat resistance and clothing surface temperature. Thus, this research can be used as a basic resource for not only calculating wuantitatively radiant heat exchange of human clothed body and unclothed body in the radiant heating system of low temperature but also designing the thermal environment in a room.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.12
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• pp.846-851
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• 2012

The radiant floor heating system is traditional heating system in korea. Radiant floor heating is small in vertical temperature difference, air stream and radiant heat distribution is uniform. And radiant floor heating system provide thermal comfort conditions to the a resident. This study was undertaken to evaluate the physiological-subjective responses of the resident's posture change such as sitting and standing. The experimental investigations were carried out in climate chamber, and subjects were 4 college-age students in good health. The physiological response was skin temperature and subjective response was undertaken survey of TSV and CSV. The results were summarized as follows; The comfortable temperature range of plantar surface was $35.1{\sim}38.9^{\circ}C$ and buttock surface was $37.8{\sim}39.3^{\circ}C$.

• KIEAE Journal
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• v.7 no.5
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• pp.65-71
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• 2007

The purpose of this study was to analyze the difference of thermal sensation by radiant floor heating as ecological design element. The experimental investigations were carried out in climate chamber, and subjects were 34 college-age females in good health. The experimental variable was radiant heat by floor heating, and experimental controlled conditions were indoor temperature, relative humidity, and air velocity in climate chamber and clothing value and activity of subjects. The results are as follows. (1) Indoor temperature($21{\pm}0.5^{\circ}C$) in climate chamber were maintained as controlling. Clothing values of the subjects were controlled as average 0.73 clo. In the floor heating-off, globe temperature was average $23.2^{\circ}C$(22.4~24.1), but in the floor heating-on, globe temperature was average $24.8^{\circ}C$(23.0~25.5). (2) In the floor heating-off, thermal sensation rating was average -1.03(slightly cool), in the floor heating-on, thermal sensation rating was average +1.03(slightly warm). (3) There were the differences of thermal sensation by radiant floor heating although indoor temperatures were maintained in an equal state. (4) The thermal sensation rating was tending upward according as the globe temperature was getting higher.

• International Journal of Air-Conditioning and Refrigeration
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• v.6
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• pp.136-147
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• 1998

An experimental facility consisting of two 3$\times$4.4$\times$2.8m rooms identical in construction is built. Each room has a control system and storage tank supplying hot water to the radiant floor heating system. The facility enables simultaneous comparison of two different control strategies each implemented in a separate room. The operating performance of three kinds of flow control scheme is tested and compared in this study: (ⅰ) conventional on-off control based on feedback from room air temperature (ⅱ) TPSC(two parameter switching control )(ⅲ) TPOC(two parameter on-off control). Results show that TPSC and TPOC using room air and surface temperature sequentially as feedback signal to control hot water supply is the better temperature regulation scheme than conventional control based on feedback from only room air temperature. They are good candidates for the room with radiant floor heating system under continuous and intermittent heating mode.

• 한국연소학회:학술대회논문집
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• 2006.04a
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• pp.19-25
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• 2006

Energy efficient and low pollution combustion systems the use gaseous fuels have been in great demand in recent year. Radiant burner in many different forms are emerging as very desirable combustion systems for same reason. Porous radiant burners are used in drying, preheating and curing, and in other type of materials processing and manufacturing processes. However, little knowledge is available about the operating characteristics and the structure of flames in porous ceramic fiber radiant burners. The objective of the present work is to investigate the global performance characteristics of the ceramic fiber burner. A detailed study which includes the spectral intensity, gas temperature, radiation efficiency and global pollutant emissions. Another objective is to study the flame structure of the ceramic fiber burner by measuring the local gas temperature. The results indicate that ceramic fiber burner do offer a 19-44% gain in radiant efficiency. The ceramic fiber burner exhibit significant spectral intensity peaks in the band at $2.0-2.5{\mu}m$. The local temperature distribution inside the mat and near the mat surface as a function of the equivalence ratio can be reasonably interpreted by the relation of the heat balance in the mat and movement of the reaction zone. Nox emission from ceramic fiber burner is less than 25ppm throughout the operating range.