K Oveisi - Department of Environmental Engineering, Najafabad Branch, Islamic Azad University ,Najafabad, Iran

Today, with regard to population growth, there is a need for more renewable energy sources that can easily serve different human needs without harming the environment; therefore, designing energy saving buildings as well as protecting natural resources is one of the main responsibilities of the experts. One of the types of renewable energies is geothermal energy, which is one of the least costly, most beneficial of these energies and a good alternative to fossil fuels, and the generation of electricity and the heating and cooling of buildings by the heat pump are a number of its applications. This article attempts to explain the use of this energy in heating and cooling buildings and the need to use this cheap and clean energy instead of using fossil fuels.Increasing population and increasing economic prosperity on the other requires energy. The increasing need for energy has led people to increasingly use fossil fuels (coal, oil, gas) but the nonrenewable and contaminations that have emerged, such as global warming, ice melting, and the collapse of the natural ecosystem of the planet, have reduced the use of these energy sources. Therefore, the use of energy sources that are unlimited and cause the least pollution has attracted the attention of researchers in recent decades, which they call the sources of new and renewable energy. One of these sources is geothermal energy, which we will continue to explain.

Geothermal Energy, Renewable Energy, Energy Applications, environment