Donghyun Seo

Impact of Solar Model Selection on Building Energy Analysis for Kuwait

This paper summarizes the results of a comparative analysis for four models utilized to predict solar radiation in Kuwait City, Kuwait. The four models include the Kasten model, Zhang and Huang model, Muneer model, and neural network based model. The analysis was based on hourly measured solar data for Kuwait City. The measured hourly solar radiation data are obtained for the year 1994 and include global, direct, and diffuse solar radiation. Non-solar weather data for the same year and site are obtained from the US National Climatic Data Center (NCDC). Weather files suitable for building energy simulation are developed using measured data as well as predictions from the four solar models. A series of simulation analysis to determine the impact of solar model selection for the weather file on the energy use predictions from a whole-building simulation program using office buildings in Kuwait. The results of the validation analysis and the simulation evalaution indicate that Zhang and Huang model is suitable for the predicting hourly solar radiation suitable for energy analysis of buildings in Kuwait.Copyright

Evaluation of Energy Savings by Optimization Control in Thermal Energy Storage System

By using both passive and active thermal energy storage (TES) systems, a significant portion of the on-peak cooling can be shifted to the off-peak period and thus the energy costs associated can be considerably reduced. This paper summarizes the results of a comprehensive evaluation of the performance of optimal and conventional control strategies for combined passive (i.e., pre-cooling building thermal mass) and active (i.e., charging ice storage tanks) TES systems for typical commercial buildings in the US. Specifically, the paper examines the impact of selected design and operating factors on the performance of optimal control strategies for combined passive and active TES systems. Among the factors analyzed include building shape, climate, adaptation of optimization control, TES systems control, and utility rate structure. The analysis is performed using a detailed simulation energy program (EnergyPlus) modified to incorporate TES models and various optimization algorithms. The results of the analysis indicate that optimal TES priority controls can achieve up to 35% in on-peak electricity demand reduction and up to 30% in total electrical energy cost savings.Copyright

Estimating Cooling and Heating Degree Days for Variable Base Temperature

Abstract In general, building energy performance is evaluated with a detailed transient building energy simulation program. However, energy evaluation tools with the bin method are still used, because of their simple and easy way to calculatebuilding energy performance, without reducing their precision. In this research, several heating and cooling degree day methodsare compared, and evaluated with their performance for variable base temperature. This analysis considered about ten yearsof the continuous outdoor temperature, in the Seoul and Busan areas. It is concluded that the simplified bin method is moreor less acceptable for Seoul and Busan, compared with the detailed hourly bin method. Key words Bin mehtod(빈법), Balance point temperature(평형점온도), Simplified mehtod(간이법)†Corresponding author, E-mail: seodh@chungbuk.ac.kr 기호설명 HDD b ： 평형점온도에 대한 월 난방도일( ℃ .day) CDD b ： 평형점온도에 대한 월 냉방도일( ℃ .day) T b ： 평형점온도( ℃ ) T h ： 시간별 외기온( ℃ ) T max ： 일최고 외기온( ℃ ) T min ： 일최저 외기온( ℃ ) T d ： 일평균 온도( ℃

Analysis of the Energy Saving Potentials for Near-Zero Energy Buildings in Shanghai

The Changning District in Shanghai has expressed interest to becoming a green neighborhood and has asked for recommendations on how to reduce the energy usage in public buildings in their district. The objective of this short study is to identify the likely range of further reductions in the energy use and carbon emissions of new buildings through energy-efficiency improvements and the use of renewable energy, i.e., solar hot water (SHW), photovoltaics (PV), and ground-source heat pumps (GSHP), as compared to buildings that meet the current public building energy code in Shanghai. This analysis is done using DOE-2.1E computer simulations of three prototypical building models — an office, a hotel, and a mixed-use retail/office building — that have been calibrated against measured energy data from such buildings in the Changning District. After the building models have been calibrated, they are then used to establish the baseline energy use for code-compliant buildings, and to calculate the energy savings for 16 potential EEMs (Energy Efficiency Measures) that exceed the building energy code. A LCC (Life-Cycle Cost) analysis is done to compare the energy cost reductions to the capital costs for the EEMs, with the result that some EEMs are rejected as being not cost-effective over a 25 year period. The usage of the EEMs accepted as cost-effective is found to reduce the energy usage of the three building types by 30–40% in the office, 43–46% in the hotel, and 35% in the retail, depending on the assumed discount rate. If all the EEMs are considered regardless of cost, the energy savings increase to 44% in the office, 47% in the hotel, and 36% in the retail.Copyright

Impact of Shape on Thermal Performance of Office Buildings in Kuwait

This paper provides a simplified analysis method to estimate the impact of building shape on energy efficiency of office buildings in Kuwait. The method is based on results obtained from a comprehensive whole building energy simulation analysis. The analysis takes into account several building shapes and forms including rectangular, L-shape, U-shape, and H-shape as well as building aspect ratios, window-to-wall-ratios, and glazing types. The simplified method is suitable for architects during preliminary design phase to assess the impact of shape on the energy efficiency of office buildings.Copyright