Saltillo Coahuila, due to the lack of an adequate architectural design, some homes do not meet the thermal environment conditions required during the winter period, it is estimated that 471,725 habitants are affected by temperatures until - 3.4°C, which causes morbidity problems, so that the need for the use of electromechanical air conditioning systems with electrical energy consumption of high economic and environmental cost arises. The objective of the work was to study the feasibility of applying a geothermal heat exchanger for home heating. Periodic variation of soil temperature at different depths was studied to determine the optimum by experimentally validated equations. An ideal depth of 3 m was determined due to a variation of 25 y 30% and lower excavation cost compared to depths of 6, 9 and 12 m.