The analysis of solar thermal systems through numerical simulation is of great importance, since it allows predicting the performance of many configurations in any location and under different climatic conditions. Most of the simulation tools are commercial and require different degrees of training; therefore, it is important to develop simple and reliable methodologies to obtain similar results. This study presents a parametric methodology to size stationary solar collector fields, with operating temperatures up to 150 °C. The costs of the collector loop piping and the pumping power of different series–parallel arrays is considered. The proposed tool was validated with experimental data and through simulations using commercial software. The tool allows establishing series–parallel arrays and calculates the volume of the storage tank according to the thermal load. The calculation is based on the system energy balance, where the mass flow and the heat losses in the interconnections of the collectors are taken into account. The number of collectors and the optimal series–parallel array were determined. The results show deviations lower than 7% in the relative error of the temperature profiles and in the solar fraction, with respect to the results obtained by dynamic simulations.

Four different shapes of a 182 m2 research greenhouse were analyzed using dynamic simulations. The thermal performance was evaluated using different cover materials at an equal floor area. In developing countries, the selection of the greenhouse shape, structure, and cover material generally is made based on the availability of the materials and considering the initial investment costs. The greenhouse is located on a cold semi-arid (BSk) climate according to the Köppen climate classification. This study aimed to determine the best choice of the greenhouse shape and cover material according to a technical-economic analysis. The analysis was conducted from a technical-economic perspective for this specific climate region. The results show the heating and cooling energy consumption for different cover materials and greenhouse shapes. The economic analysis was made to assess the investment and operative costs through the life span of the greenhouse.

In Mexico, residents of low income housing mainly achieve thermal comfort through mechanical ventilation and electrical air conditioning systems. Though government and private efforts have risen to meet an increasing demand for social housing, the average construction quality and thermal comfort of new housing stock has decreased over the years. Various programs and regulations have been implemented to address these concerns, including the 2011 residential building standard NOM-020-ENER-2011. This standard attempts to limit heat gains in residential buildings, in order to reduce the energy consumption required from cooling systems, and was intended to be applied throughout Mexico. NOM-020-ENER-2011, however, divides the country into just four climatic zones and only considers the energy use of cooling systems, disregarding heating costs. The recommendations of this policy are thus inadequate for the many regions in Mexico that have mild to moderate winters. This study discusses the assumptions and calculations that underlie NOM-020-ENER-2011, identifying several problems and recommending specific changes to the standard that would lead to greater comfort and lower energy use throughout Mexico.