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Energy recovery ventilators (ERV) have become popular in Korea for their use in minimizing heat loss in ventilation and maintaining indoor air quality (IAQ). The performance of ERV systems is determined by laboratory tests under prescriptive indoor and outdoor conditions. Typically, a fixed heat recovery efficiency of the ventilation system is used in building energy simulations. In this study, in order to analyze the heat recovery efficiency of an ERV under actual operating conditions, long-term field measurements were performed in a residential building in the winter. The results showed that the enthalpy heat recovery efficiencies fluctuated between 25% and 70% depending on the outdoor conditions. The sensible heat recovery efficiencies were between 30% and 65% and were proportional to the temperature difference between indoors and outdoors. The heat exchange efficiency of ERV was not constant but varied according to changes of indoor and outdoor conditions under actual operating conditions. A simulation method was used to analyze the effect of the ERV's variable heat exchange efficiency on heating energy demand in the heating season. Two cases were analyzed. Case 2 analyzed the variable heat exchange effectiveness of the ERV based on the field measurements. Case 1 examined the fixed effectiveness proposed by the manufacturer. Simulation results showed that the heating energy demand in Case 2 was 69% higher than that in Case 1. This means that the heating energy demand may be underestimated if the heat exchange efficiency of the ventilation system is assumed to be constant in the simulation.

Since ratification of the Kyoto Protocol, governments worldwide have announced energy policies to greatly reduce energy use and greenhouse gas emissions. The construction sector accounts for approximately 40% of global energy usage. Therefore, technological as well as political means have been employed to realize a reduction in energy consumption in this sector. High-efficiency window systems can play an important role in reducing energy consumption in buildings. We measured the thermal performance (U-factor) of different window systems and analyzed their effects on energy savings. All systems considered in this study helped improve insulating performance. Our results showed that the use of temperable, low-e glazed units helped achieve 19.9%, 17.1%, and 15.2% energy savings in the study areas in the central and southern regions in South Korea and in Jeju Island, respectively. Despite the great potential for energy savings in the central region, only half the buildings qualified for Rating 2 certification, whereas all buildings on Jeju Island qualify for the most energy efficient rating. This suggests that the energy efficiency ratings for buildings in South Korea are being applied to these three regions according to the regional building codes and climatic conditions.

This study was designed to investigate a method for short-term, real-time energy demand prediction to cope with changing loads for the effective operation and management of buildings. Through a case study, a novel methodology for real-time energy demand prediction with the use of weather forecasting data was suggested. To perform the input and output operations of weather data, and to calculate solar radiation and EnergyPlus, a BCVTB (Building Control Virtual Test Bed) was designed. The BCVTB was used to predict daily energy demand, based on four kinds of real-time weather data and two kinds of solar radiation calculations. Weather parameters that were used in a model equation to calculate solar radiation were sourced from weather data of the KMA (Korea Meteorological Administration). After conducting energy demand prediction for four days, it was found that all inputted weather data have an effect on the prediction results. These data were applied to real buildings in order to examine their validity. The information data exchange between real-time weather data and simulation data was carried out fairly through the BCVTB.

A new electrical lighting and daylighting simulation analysis environment is developed to help designers assess optimal design configurations and operating strategies for electrical lighting fixtures in order to reduce energy use. In this paper, two applications of the simulation environment are presented to optimize the electrical lighting circuiting layouts design and the location of desks within daylight spaces. The results from these applications illustrate how the simulation environment and optimal daylight-base lighting controls can help building and lighting engineers and green building consultants improve the design of lighting and daylighting systems in order to construct and operate high energy performance buildings.