Ali Siavoshi Kord - Msc, K.N.Toosi University of Technology
Kaveh Farhadi - Msc, Payame Noor University
Seyed Ali Jazayeri - Associate Professor, K.N.Toosi University of Technology

The heat pumps have a key role in development of clean energy and have a major effect on harvesting low energy resources. In this article the importance of heat pumps and possibility of extracting geothermal energies as a major source of renewable energies has been considered. Initially detail effects of heat pumps on reducing carbon dioxide when producing same heating loads for Tehran environmental conditions versus common heating systems which consume fossil fuel has been carried out. Also a comparison of GSHP operating costs to those of conventional space and water heating systems is considered. Later an extensive thermodynamic analysis of a geothermal heat pump for heating purposes has been investigated through energy, exergy, entropy and enthalpy balance relations applied to a U-bend GSHP system where the results are presented for the city of Tehran. At the same time the importance of using refrigerants which are more compatible with environment has been analyzed through a set of different refrigerant to investigate the influence of coefficient performance and heat pumps exergetic efficiencies.

Ground source heat pump; CO2 emission; cost saving; refrigrant; COP