• Journal of the Korean Wood Science and Technology
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• v.38 no.6
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• pp.518-525
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• 2010

Infrared (IR) thermography which is the technique for detecting invisible infrared light emitted by objects due to their surface thermal condition and for producing an image of the light has been applied in various field without damaging the objects. It also could be used indirectly to examine the inside of an object. In this study, insulation property of wooden house in Korea Forest Research Institute (KFRI) was evaluated with according to "Thermal performance of building - Quantitative detection of thermal irregularities in building envelopes - infrared method (KS F 2829)". This method uses "Temperature Difference Ratio (TDR)" between outdoor wall surface and indoor wall surface of wooden building for evaluating its thermal performance. The thermal performance of a room on the 2nd floor of the wooden house was focused in this study and IR thermography on the indoor and outdoor surface of the house was captured by IR camera. Heat loss from the corner and the window of the wooden house as well as wall of the house was quantitatively evaluated and the invisible heat loss in the wall was detected. It is expected that the results from this study could contribute to improve the wooden building energy efficiency.

• KIEAE Journal
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• v.15 no.6
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• pp.81-86
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• 2015

Purpose: Condensation in the apartment housing is one of the most significant defects and complaints for condensation are rapidly increasing according to the growing interest in residential environment. Korea government established a regulation for reducing condensation in the apartment housing and TDR is adapted as a standard. However prevention of condensation depend on improving the performance of building envelop has limitation because of the increase of the cost. Centralized Hybrid ventilation system is suggested to prevent condensation. Method: Field measurement was conducted to verify the ventilation rate of the ventilation system. Based on the measurement, air network and CFD simulation was conducted to analyze ventilation rate for each room. Surface temperature was calculated by regulated TDR according to the regions and surfaces. The performance of condensation prevention was evaluated by the ventilation rate and surface temperature. Result: In the results, it was found that condensation was prevented in more than 90% of households by the centralized hybrid ventilation system which provided 0.19 ~ 0.81ACH for each room.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.718-723
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• 2009

The purpose of this study is to present an in-site evaluation method for building insulation performance using Infra-red camera. The research contents of this study are to evaluate validity and suitability of building insulation defect survey using Infra-red camera for apartment housing with temperature & heat flow pattern analyze method. By establishing the in-site evaluation method building insulation performance using infra-red camera, it is expected that 1) building envelope repair market will be activated by using developed method in ESCO and remodeling companies, 2) the method developed in this research will contribute to reduce national energy consumption by promoting old building insulation remodeling.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.730-735
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• 2009

The purpose of this study is to consider improvement performance to prevent condensation and draw the optimum insulation design method for building using simulation tool. In this study, the three corners, weak part in condensation, were conducted by three-dimensional steady state simulation. From the results, it is required to strengthen insulation design, and it is founded that existing insulation system typically applied to most Korean apartment buildings has serious insulation defect that insulation is disconnected by structural components at the joints of wall-slab and wall-wall in envelope. So, it is considerate to need a concrete technology improvement.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.11
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• pp.573-577
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• 2013

An external window directly affects the energy performance of its building. In modern well-insulated buildings, U-values for walls of 0.36 $W/m^2K$ or even lower can be realized. In such buildings, glazing with typical U-value of 2.1 $W/m^2K$ or higher creates thermal weak spots on the facade. The performance of the existing triple glass window has been limited to energy savings and condensation prevention. In this study, the performance of condensation prevention of a vacuum multi-layer glass was analyzed. The final conclusion through mock-up experiments is as follows. The surface temperature of the vacuum multi-layer glass was $2^{\circ}C$ higher, and the temperature difference ratio (TDR) was 0.07 lower, than the corresponding values of the triple glass.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.6
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• pp.404-412
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• 2010

The purpose of this study is to accomplished an in-site evaluation method for existing building insulation status using Infra-red camera and to consider improvement performance to prevent condensation and draw the optimum insulation design method for building using simulation tool. The research contents of this study are to evaluate validity and suitability of building insulation defect survey using Infra-red camera for apartment housing with temperature and heat flow pattern analyze method. Based on this research, the three corners, weak part in condensation, were selected in apartment building and conducted simulation by three-dimensional steady state. From the results, it is required to strengthen insulation design, and it is founded that existing insulation system typically applied to most Korean apartment housings have serious insulation defect that insulation is disconnected by structural components at the joints of wall-slab and wall-wall in envelope. Thus, it is considerate to need a concrete technology improvement.

• KIEAE Journal
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• v.17 no.2
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• pp.5-12
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• 2017

Purpose: Under the purpose of presenting the adequate remodeling period for the improvement of thermal insulation performance of external walls in deteriorated buildings, the change in external wall and residential environment problem(dew condensation) due to aged deterioration after the apartments were constructed in Korea were analyzed. Method: Temperature Difference Ratio Outside(TDRo) and Heat Flow Meter(HFM) were used as measurement methods to evaluate the thermal insulation performance of deteriorated buildings. For TDR evaluation, thermo-graphic camera was used to measure and analyze the surface temperature of external wall. Also, dew condensation evaluation was analyzed using the Temperature Difference Ratio Inside(TDRi). Result: As a result of analyzing thermal performance through TDRo, the first decline point of thermal insulation performance began after 14-16 years have passed since construction was completed, and after 20 years have passed the decline point of thermal insulation performance reappeared. As a result of analyzing U-value with HFM measurement method, the decline rate of external wall's thermal insulation performance is lower than 2% in average at around 5 years after completion, and 8.7% in average at 10-15 years, and over 10.2% in average at 20 years.

• KIEAE Journal
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• v.17 no.4
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• pp.89-94
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• 2017

Purpose: Condensation in walk-in closets attached to apartment bathroom has been known as an emerging issue that may threat occupants' comfort and health. Despite a number of design guidelines and enforcements to prevent condensation, condensation issues may still occur depending on various cases and scenarios. We aim to identify what condensation scenarios may lead to walk-in closet condensation and/or worse the existing condensation issues. Method: First we choose an actual walk-in closet of an apartment that suffers from sporadic condensation and resulting mold and mildew. Then we observe its relative humidity and temperature after the bathroom is used, in which excessive vapor is thought to be transported to the walk-in closet. We analyze Temperature Difference Ratio - a domestic indicator of condensation occurrence, and dew point temperature to compare it with surface temperature using 2D heat transfer simulation upon various condensation scenarios. Result: TDR of the test walk-in closet turns out be OK despite mold and mildew actually occurring. Hot water pipe installed in the floor would greatly reduce condensation. If hot water pipe in the upper floor, however, is not used, or hot water pipe of the closet is turned off during swing seasons, it is expected that condensations may still occur.