As the Inter-floor Thermal Insulation Regulation of apartment house applies, in this study, indoor thermal performance and downward heat loss between the cases when insulation exists and doesn t exist change in the thickness of the structure slab under the inter-floor noise isolation standard, and thermal characteristic of typical floor structure will be compared and analyzed through simulation. And the resultant information will be provided as the basic data for designing Ondol heating design suitable for the property of apartment houses in Korea. As the Inter-floor Thermal Insulation Regulation applies since 2001, upward thermal performance was found to increase by 2~3% but downward heat loss decrease by approx. 30% or more representing that remarkable portion of downward heat loss is reduced. As result of comparing five prototype floor structures, upward thermal performance of the standard floor structure was found to be 70~71 W/㎡ while downward heat loss was, in the case of prototype floor structure, 10~11 W/㎡. As result of simulating the change in thermal performance as per the height of hot water supply pipes, it was found that upward thermal performance increases as the height of pipe gets higher. On the other hand, the difference of temperature between the place right above the pipe and the in-between place gets larger, which implies that thermal performance and difference of hot water temperature should be taken into account in the design of Ondol structure. The difference of upward thermal performances according to the height of pipe and downward heat losses were found to be approx. 10.8% and 5.81% respectively. The thermal performance information in prototype floor structure suggested in this study will be used for the basic data for the design of Ondol heating design.

Recent apartment houses tend to expose the problems of unbalanced floor temperatures and real temperature due to changes in thermal performance arising from reinforced insulation and air tightness. In this study, the indoor thermal environment was analyzed against the apartment unit household in the type of individual heating, central heating, and District Heating methods in order to determine the operational status of indoor thermal environments and heating system by Heating supply systems. The temperature of hot water supplied at the time the indoor loads occurs to the maximum by Heating supply systems was found to rise in order to individual heating (70℃) , central heating(47℃) and District Heating (41℃). The hot water supply frequency showed variable changes in the range of 3 to 6 times per day in cases of individual heating while periodical changes was ranging from 3 or 4 times a day in the case of central heating and district heating. The width of variation of floor surface temperatures depending on the temperature of the supply water was found to be in order of Individual Heating, District Heating, and Central Heating. The average floor surface temperature appeared similar to the hot water supply temperature pattern in the order of 26.4 to 30.2℃ for Individual Heating, 28.2 to 28.6℃ for Central Heating, and 24.8 to 29.4℃for District Heating. In the case of non-heating where heating is not implemented, the temperature of the floor surface was 22.8℃ to 26.0℃ showing the same temperature as the indoor temperature. Heating supply appeared to be maintained in a stable manner overall in a sporadic manner ranging from 3 to 6 times a day, which was maintained in a stable manner on the whole regardless of the heating method.

This study is to develop the new type of environmentally friendly Ondol system for improvement of energy efficiency, improvement of impact sound insulation of floors and reduction of material & resources in apartment houses. The prototypes for development of the Environmentally Friendly Ondol System of Double layer (E02 System) are designed and are made as the manufactures in order to improve energy efficiency & the impact sound insulation of floors and reduce material & resources in apartment houses. The performance measurement of impact sound insulation of floors is tested. and the performance on the E02 System is compared with the existing Ondol system. As a result, the impact sound insulation of floors of the E02 System is improved more 15 dB than standard level. The E02 System got the first grade Certificate on the impact sound insulation of floors. The performance of thermal insulation and energy efficiency is compared the E02 System with the existing Ondol system. The E02 System is evaluated as more 9% of energy efficiency than the existing Ondol system. The component weight per area of the E02 system is 96 kglm', and it is evaluated as reduction of the existing structure weight. Therefore the E02 system will be utilized as solution for pending problems in apartment houses in Korea.