Ali Asnaashari - Department of architectural Engineering, Islamic Azad university south Tehran branch, Tehran .Iran

The limitation of fossil fuel sources and the pollution resulting from their consumption hasprovided important solutions to reduce energy consumption. To date, the world consumes energyfrom various sources and it comes mostly from fossil fuels, but there are numerous issues andproblems, including restrictions and the fossil fuel resource depletion and environmental impactsof burning these resources necessity to save energy by optimizing it. This research-based oncomputer modeling and simulation. In this research, the first phase of the existing building issimulated and the amount of cooling and heating is calculated, then change the HVAC system toa geothermal system and appropriate insulation, cooling and heating rates were calculated andcompared with preliminary results. In this study, design-builder software version ۴.۵.۰.۱۴۸ wasused to simulate and perform building energy analysis. Simulation results for energyconsumption in the geothermal system show ۲۵.۵% electricity saving and ۶۰% gas saving.

optimization, energy consumption, geothermal, renewable energy, energy simulation, analysis