Korea is the tenth energy-intensive country in the world which imports over 96% of total energy consumption from abroad and ranked the ninth in carbon dioxide emission in the world. Korean government has developed new and renewable energy extensively to change such an energy consumption for the purpose of improving energy efficiency and green growth.
New and renewable energy is defined as "the energy generated by using fossil fuels or natural resources such as sunshine, water, geothermal energy, rainfall and living organism". New energy is generated by three energy sources including eight energy sources such as "fuel cell, liquefaction and gasification of coal and hydrogen energy" and renewable energy includes "solar heat, solar photovoltaic, bio energy, wind power, small hydro power, geothermal energy, ocean energy and wastes energy".
Nam-gu Office of Gwangju metropolitan city was supported to install new and renewable energy based heating and cooling facilities for public health center which used fossil fuel, urban gas from Energy Management Corporation and this study was in initiated from the researcher's involvement in the design of this system.
The building to be examined has the load capacity of cooling (259kw), heating (316kw) and geothermal capacity of cooling (333.8kw) and heating (335.4kw).
In the process of design, first the loads necessary for building were calculated with such data as insulating and finishing materials, internal load and ventilation load of building. Second, test drilling for thermal conduction test was conducted, PE pipe for heat exchanger was installed underground, water was circulated for 2,882 min. and then heat exchanger quantity, drilled hole quantity and geothermal heat pump capacity were calculated with thermal conduction rate (2.83W/mK).
Third, geothermal circulating pump, hot and cold water circulating pump, expansion tank, buffer tank and apparatus were calculated with the estimated load, all equipments were arranged in machinery room and piping connected with each equipment was installed.
As a result of employing geothermal system to the building of the study and comparing the system with existing urban gas energy consumption, it was found that the energy consumption of January showed energy saving rate of 7.1%, that of February 7.6%, that of March 14.8%, that of July 37%, that of August 34%, that of November 14.4% and that of December 22.3%. And this study confirmed the effect of energy saving effects of 7.1~37% compared to existing urban gas heating and cooling system. In addition, cooling tower installed on the front of the building was removed to block noise and prevent civil complaint and moreover the effects of promoting the use of new and renewable energy to residents were also great.