Energy consumption of mankind brings about the transglobal problems, such as global warming and ecological destruction, causing huge environment load, as well as exhaustion of energy and the environment destruction. Accordingly, each country in the wo...
Energy consumption of mankind brings about the transglobal problems, such as global warming and ecological destruction, causing huge environment load, as well as exhaustion of energy and the environment destruction. Accordingly, each country in the world is trying to establish concrete countermeasures through the studies to reduce greenhouse gases, recognizing earth environment destruction caused by global warming as the survival threat that mankind is facing in the 21st century. In the field of architecture, buildings that save energy and reduce CO₂ emission are proposed in order to realize 'Sustainable Architecture' as counterplan for earth environment problems, and environmental performance and economical efficiency are evaluated in accordance with energy consumption and environment load of buildings life-cycle , applying Life Cycle Assessment and Life Cycle Cost Analysis.
In this study, it was designed to propose concreter economical efficiency evaluation method to which Life Cycle Assessment and Life Cycle Cost Analysis were applied, in consideration of life-cycle and environmental cost of sustainable technology for multi-family residential buildings that is able to save energy and reduce CO₂ emission. And it was to provide basic data which sustainable technology for multi-family residential buildings may be planned at the initial buildings design by comparing and analyzing comprehensive results of economical efficiency evaluation. The summary of the results of this study is as follows.
1. Economical efficiency evaluation method of sustainable technology
1) The basic hypotheses to implement Life Cycle Cost Analysis of sustainable technology for multi-family residential buildings were established. Concrete methods, in which environmental elements such as energy consumption and CO₂ emission were taken into, were proposed, according to the establishing method of major variables and selection of data, such as period of analysis, discount rate, energy escalation, and present worth factor.
2) Environment cost item, which is designed to convert the environment performance of sustainable technology into the cost, was established among the cost items, and it was divided into energy cost and environment allotment.
3) In order to compute energy cost and environment allotment, energy consumptions and CO₂ emissions were calculated through the performance assessment of sustainable technology, and the price of each energy resource and CO₂ emission right were applied.
4) In the case of construction cost for Life Cycle Cost Analysis, the cost was computed, which was taking place additionally or reduced through replacement existing facilities as sustainable technology was applied to multi-family residential buildings
2. Environment performance of Sustainable Technology
In the aspect of energy saving and CO₂ reduction, sustainable technology which is highly applicable to multi-family residential buildings was selected and was evaluated environment performance. In general evaluation of environment performance of a building is carried out as it is centered on environment load, though the evaluation includes many purposes such as energy saving, resource saving and natural environment preservation. In this study, environment performance was carried out evaluation on CO₂, which is used as the index of earth environment problems like global warming. When environment performance was compared based on reduced quantity of CO₂ emission, double skin facade system was the most excellent, geothermal heating and cooling system and hybrid ventilation system and solar heating system took the places in the order named.
3. Economical efficiency of Sustainable Technology
1) As for individual economical efficiency evaluation of sustainable technology, Life-Cycle Cost Analysis values were compared according to the case in which sustainable technology was applied and the case in which it was not applied. In this study, it was analyzed that all sustainable technologies secured economical efficiency during the analysis period through environmental cost saving, except for photovoltaic power system. It was disclosed that the economical efficiency of photovoltaic power system was affected most by the price change of main equipment such as the PV panels and the inverter. However, the prices of equipment were going down as photovoltaic power system were expanding to the greater part of world-wide renewable energy market and new technologies were being developed. Taking into account that the speedy rising of energy price and the environment allotment increasing by CO₂ emissions, we can conclude that photovoltaic power system will secure the economical efficiency in the near future.
2) Economical efficiency comparison among sustainable technologies was based on size of earnings which was taking place in case sustainable technology was applied. When economical efficiency of sustainable technologies based on the earnings which occurred in case sustainable technology was applied, geothermal heating and cooling system was the most excellent, and double skin facade system, hybrid ventilation system and solar heating system took the places in the order named.
3) When economical efficiency analysis result were integrated, it was identified that the biggest factor that had the most powerful influence on the economical efficiency of sustainable technology was the energy cost that occurred at the period of operation when the e sustainable technology was not applied. And it was disclosed that gas bill had the biggest influence among the energy resources. Therefore, it was estimated that the strategy to reduce gas consumptions shall be involved in energy saving plans of multi-family residential buildings, in case the situation, in which the speedy rising of fossil fuels maintains continuously.
The result of this study may not be absolutely reliable to apply due to performance improvement of sustainable technologies, or the change in price of equipment and energy in the future. However, the results may be used as the useful data in applying sustainable technologies to multi-family residential buildings by presenting the comprehensive forecasting method for the near future and analyzing the results of forecasting.