One of the current problems is the use of energy obtained from fossil fuels, especially due to the emission of greenhouse gases. An option to replace fossil fuels is the use of alternative energies such as solar or wind energy. The objective of this work is to carry out a thermal and energy analysis of an indirect air heating system that receives energy through solar collectors that operate with water as the thermal fluid used in a food dehydration system, in order to know the efficiency of the system and therefore, make improvements to the circuit, in addition to the characterization of the water storage tank of the system, obtain the amount of energy that can be provided and the behavior of temperatures at different operating flows. According to the methodology, the temperature profile was obtained inside the hot water tank in two modes of operation (heating and energy extraction) reaching temperatures of 50 to 70 ° C, where the optimum temperature for drying is found and in turn reaching an efficiency 84%, compared to a conventional drying system that uses LP gas.

The objective of this research is to quantify the UV Index in the city of Zacatecas. The UV Index is a measure of the intensity of UV radiation at the earth's surface and is an indicator of its ability to cause skin damage. UVB radiation is the main cause of skin cancer. The Methodology consisted of collecting ultraviolet radiation data (UVB) in the period from January 1 to December 31, 2019, using a Solar Ligth 501-A Biometer, installed in the Zacatecas_04 solarimetric station belonging to the National Solarimetry System, located in Building E6 of the UAZ Siglo XXI Campus. Subsequently, the data was transformed to the UV Index (2.332 by the Biometer reading in Med/hr to W/m² at IUV). The results that were obtained in the period of time evaluated show that most of the year the radiation received is high and very high according to the sun protection system recommended by the O.M.S. UVB exposure begins with greater intensity at 10:00 am until 4:00 pm. Concluding, that in the city of Zacatecas most of the year there is a high UV Index.