Comparative study of geothermal and conventional air conditioner: A case of study for office applications

The high cost of electricity has done that the air condition sector search for alternatives to produce cold efficiently. It is a necessity, especially in Brazil, where 17% of the total electricity consume in residences is due air condition systems. Many studies have presented technical -economic data of heat-pumping and air conditioner systems but there is a lack of studies that consider applications with only cooling demand. This work presents a comparative analysis of conventional and a ground source air conditioning system. The geothermal air conditioner used an open loop water. The systems are design and simulated for cooling an office considering the climate of three Brazilian cities. To evaluate the performance of the geothermal and conventional air conditioner a model was developed using the Equation Engineering Solver (EES). The model was partially validated using another mathematical model and the mean difference of COP obtained in both models was 1.7%. The results are presented for twelve different scenarios based in three water well temperatures and four water well depth for each city. In the best scenario, the geothermal system has annual energy consumption 34% lower than conventional system and a payback time of 1.4 years.

Automated summary

Due to the high cost of electricity, the air conditioning sector is seeking efficient alternatives to produce cold air. This is especially necessary in Brazil, where 17% of residential electricity consumption is due to air conditioning systems. While there have been studies on the technical and economic data of heat-pumping and air conditioning systems, there is a lack of research considering applications with only cooling demand. This study presents a comparative analysis of conventional and geothermal air conditioning systems, using an open loop water system. The results show that in the best scenario, the geothermal system has 34% lower annual energy consumption compared to the conventional system and a payback time of 1.4 years.