This research paper presents a review of factors which influence the thermal comfort inside of vehicle. These factors can be classified in two classes: measurable factors, which include: the air temperature, air velocity, radiant temperature and relative humidity and personal factors which include: activity level and clothing insulation. An optimal level of the thermal comfort inside a vehicle can only be achieved by taking into account these measurable and personal factors. Based on these factors we can calculate Predicted Mean Vote (PMV) which represents the average thermal sensation felt by a group of people placed in the vehicle and determining the Predicted Percentage of Dissatisfied (PPD) index, which is the quantitative measure of thermal comfort of a group of people at a particular environment

The paper presents actual knowledge concerning the indirect evaporative cooling (IEC). This cooling technology is promising to develop in the near future due to its very low energy consumption and high efficiency in its range of applications. The review is presenting in details: theory, working principles, flow and construction. The IEC equipment and technology is suitable in different air conditioning applications: commercial, industrial, residential or data centres. The IEC technology is completely environmental friendly and has very low global warming impact. The single disadvantage of IEC is the water consumption

SThe paper presents a review of indirect evaporative cooling (IEC) operating conditions and performances. This cooling technology is promising to develop in the near future due to its very low energy consumption and high efficiency in its range of applications. The review is presenting in details: operating conditions and performances. Having very low energy consumption comparing to classic cooling, the IEC technology is environmental friendly and has very low global warming impact. The single disadvantage of IEC is the water consumption. The review also includes a study concerning the limits of IEC for different locations world-wide

The study presents a mathematical investigation on the potential to provide electricity of different solar Organic Rankine Cycle systems and of a photovoltaic system. As input data for all the systems, were considered multiannual climatic data for Cluj-Napoca, Romania. The solar field was considered in three configurations based on flat collectors, on evacuated tubes collectors and on parabolic trough collectors. The Organic Rankine Cycle was modelled for three working fluids considering the thermal regime typical for each type of solar collectors. It was found that the maximum electric power for the solar thermal systems was situated in the range of (58.57 … 86.57) W/m2 of solar collector and for the photovoltaic system was of 103.06W/m2 of photovoltaic collector. The maximum global efficiencies of the investigated solar thermal systems was situated in the range of (6.73 … 10.23)% while for the photovoltaic system was of 10.81%. Between the solar thermal systems, the most efficient proved to be the one based on evacuated tubes collectors. Additionally it was investigated an existing solar thermal system based on heat pipes solar collectors, located in the vicinity of Timişoara, Romania which left without consumers and in need to be converted into an electrical system

This study presents an investigation concerning the conversion of solar radiation into heat, cold, and electricity on the facades of virtual buildings located in four different cities that correspond to different climatic conditions. Two of the cities are in Eastern Europe, Romania, one city is situated in Western Europe, Spain, and one city is on the western coast of the United States. Four different solar active applications integrated in the facades were investigated: heating based on flat solar collectors, cooling based on a LiBr-${\mathrm{H}}_2\mathrm{O}$ absorption cycle, photovoltaic conversion of solar radiation in electricity, and conversion of heat into electricity based on an organic Rankine cycle. The facades most suitable for investments in the solar active applications were recommended and it was found that both location and the type of application were influencing such recommendations. For both locations in Romania the facade facing west was recommended for all types of applications. For the location in Spain, for both heating and cooling, the first recommendation is the facade facing east and the second recommendation is the facade facing south. Although for electrical applications, the first recommendation is the facade facing south, and the second recommendation is the facade facing east. For the location in the United States, for heating and cooling, the first recommendation is the facade facing west, and the second recommendation is the facade facing south. Although, for electrical applications, the first recommendation is the facade facing south, and the second recommendation is the facade facing west.

District heating and cooling systems represent a great pillar of European cities aiming to achieve climate neutrality. This study investigates stakeholders’ perspectives on district heating and cooling to analyze the challenges, barriers, and potential accelerators of a sustainable low-carbon energy transition in urban areas. This study was performed via a survey-based approach, targeting multi-level stakeholders, both from the supply and demand side. This study employed a structural methodology involving customized surveys tailored to different stakeholder groups, aiming to understand challenges, advancement, and opportunities in Romania’s district heating systems. The results highlighted the diverse interests of stakeholders, emphasizing the need for financial support to reduce reliance on fossil fuels from the supply side while addressing concerns about infrastructure and current operations from the demand side. This study laid the groundwork for shaping national and regional policies and promoting local partnerships to reduce fossil energy demand and support the transition to renewable energy sources. Using a multi-stakeholder, cross-sectorial approach, and SWOT analysis in Romania, it systematically addresses technical, financial, and regulatory challenges for the greater sustainability of these systems in the urban environment.