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Solar cooling systems, specifically solar absorption cooling systems, are becoming an attractive subject since they are great alternatives to the conventional cooling systems which lead to high electrical consumption. In addition, this system can provide cooling without greenhouse gas emissions. Hence, many combinations of different components might be adopted to apply the solar absorption cooling system. This paper will discuss the absorption chiller working cycle, the absorption chiller working fluids, the solar collectors to be combined with solar cooling systems and the single-effect absorption chiller. Furthermore, the variation of the coefficient of performance, the solar fraction and the economic study will be discussed. The goal of this review is to present previous studies and analyze their results; highlight the environmental, energetic, and economic viability of such systems and tackle future challenges regarding solar absorption cooling system and discuss the application of this system on new climates and more specifically on Lebanon.

A substantial share of the total energy in various countries is consumed by industries and manufacturing sectors. Most of the energy is used for low and medium temperature process heating (up to 3000C) as well as low and medium cooling capacity (up to 350kW). To meet the demand, the industrial sector consumes most of its energy in either thermal (heat) or electrical energy forms. The use of fossil fuels accounts for about half of the overall share. This resulted in a necessity to commercialize local and clean renewable energy sources efficiently considering the reduction of economic dependence on fossil fuels and greenhouse gases emission. As such, solar energy has proven potential and resulted in considerable development and deployment of solar heating industrial processes (SHIP) and solar cooling systems in recent times. Thus, an attempt to present a review of the available literature on overall energy intensiveness, process temperature levels, solar technology match, and solar thermal system performance and cost have been made in this paper. The review also includes identifying the potential and relevance of involving solar thermal for industrial heating and cooling demand. As a result, at least 624 SHIP including promising large-scale plants and 1350 solar cooling systems most of them in small and medium capacities in operation are identified. Though limited data is available for solar cooling potential and installation, investigations projected the global SHIP potential to 5.6 EJ for 2050. Consequently, given the presence of many low and medium temperature heating processes and cooling capacities in industries with immense solar energy potential, developing counties such as Ethiopia can take experience and pay attention to the development of sustainable industrial systems.

The rotary desiccant wheels application in the air conditioning systems are used for the air dehumidification by means of hygroscopic layers for water vapor adsorption. Nevertheless, external heat sources are required for water desorption to close the air treatment cycle. This paper investigates on the possibility to integrate in that cycle a new component, such as the trans-critical CO2 heat pump, to reduce the contribution of external thermal sources. In so doing, the high temperature waste heat discharged by the heat pump hot sink can be fruitfully exploited. Additionally, a PV array has been added to the typical layout based on the solar collectors, in order to assure the heat pump electrical driving. The energy analysis is carried out by calculating the energy performance indicators of the whole cooling system, simulating it by a dynamic model built in the MATLAB SIMULINK environment. Specifically, an air handling unit has been properly sized to supply cooling load to a reference conference hall of 1200 m3, with changes in boundary conditions (i.e. solar radiation, daily temperature and relative humidity variations). Indeed, three different cities representing the most typical Italian climatic zones, have been considered for assessing the proposed technical option suitability., Highlights • A quick overview on the Trans-critical CO2 heat pumps features has been presented. • Dynamic simulation model of a hybrid solar cooling systems with CO2 HP has been built. • Fundamental equations of each component have been reported and implemented in Matlab. • Hybrid system energy performance has been evaluated in three different Italian cities. • Other key performance indicators have been presented and discussed.

The cooling of the surface of the solar photovoltaic (PV) system is a major operative factor in achieving greater efficiency. Correct cooling can improve electrical efficiency and reduce cell degradation rates over time. This results in increasing the life of the solar PV modules. In industrial and domestic utilization, the cooling system is used for the removal of excess heat. This paper presents a new method for cooling systems for solar PV which results in the improvement in the collection of the solar insolation. The additional feature of the method has been the tracking of sunlight for efficient power generation. Further, the extra heat can be utilized for other purposes including heating and power generation through thermal means. The concept of the proposed system has been explained in detail with the pictorial representation. Also, for the validation of the improved performance of the proposed system, a detailed comparison with the conventional methods have been provided for five different cities of Saudi Arabia and an improvement of twice collection of insolation has been estimated compare to the conventional systems. The proposed system shows improved performance for all operating conditions.

Solar-powered air conditioners offer a high potential for energy-efficient cooling with a high economic feasibility. They can significantly reduce the energy consumption in the building sector, which is essential to meet the greater ambition of reducing greenhouse gas emissions by 80% in the EU by 2050. This paper presents a computational model development capable of simulating the behaviour of a photovoltaic-assisted heat pump in different locations and working conditions. In addition, this model has been used to optimise a solar on-grid air conditioning system. The generated model has been validated with experimental data obtained in a real facility for a whole summer of operation (more than 100 tested days) in a Mediterranean climate (Alicante, Spain). According to the simulation results, the average Energy Efficiency Ratio (EER) of the system is 16.0, 10.7 and 7.8 in Barcelona, Madrid and Seville, respectively. The optimisation analysis has proven that the severity of the climatic region increases the costs as well as the optimum PV power to drive the AC unit. The obtained values for the the PV power and the annualised cost are 400 W and 506.2 € for Barcelona, 900 W and 536.7 € for Madrid, and 1300 W and 564.7 € for Seville. The annualised cost and the CO2 emission levels are higher for the conventional system (no PV panels) than for the solar on-grid system, regardless of the installed PV power. This difference can be up to 66.64 € (10.55%) and 112.94 kg CO2 (64.83%) per summer season in the case of Seville.

Growing populations, burgeoning economies, and technology-driven lifestyles demand an increasing supply of energy. The existing energy supply pattern primarily depends on fossil fuels that have initiated climate change–provoking myriad problems. Integration of renewable energy sources in the existing energy supply system is a complex and challenging task keeping in view the depleting fossil fuels and prevailing environmental challenges. The existing cold storage farms are working on traditional compressors and the HVAC system, causing more use of electricity. Similarly, existing data centers and supermarkets are also using conventional refrigerants. These systems also use hazardous environmental refrigerants, which make these systems more dangerous. In the summer season, comfort cooling and refrigeration requirements rise to peak in hot climate areas forcing utilities to supply more electrical energy to meet the demand. Therefore, a solar thermal cooling system employing a solar absorption chiller operated through a hot water stream generated by a solar evacuated glass tube collector with CO2 as a refrigerant is simulated in the TRNSYS® simulation environment. The results are generated for the hot climate of Multan, Pakistan, and the average obtained temperatures of the three rooms, cold storage, office, and kitchen room, were 18.43, 26.25, and 29.83°C, respectively. However, every startup or new idea needs a proper business model before entering into the market. This article offers a complete insight and a future perspective for the reader to develop a precise business model for the commercialization of his or her project. A business model is designed for solar thermal air conditioners for domestic, cold storage, and data centers applications in the world, after reviewing and interviewing manufacturers and customer segment in air conditioning fields. Data were collected through semi-structured one-to-one interviews from a convenient sample of 10 national and international respondents, and their views were thematically analyzed. The implementation of a business model using a case for the Pakistani market is presented. A business model for a solar cooling system utilizing abundant CO2 as a refrigerant is presented in this article. This business model is equally suitable for designing a business model for any renewable energy product in the world.

The design of renewable energy systems for Nearly Zero Energy Buildings (NZEB) is a complex optimization problem. In recent years, simulation-based optimization has demonstrated to be able to support the search for optimal design, but improvements to the method that are able to reduce the high computation time are needed. This study presents a new approach based on deep residual learning to make the search for optimal design solutions more efficient. It is applied to the problem of system design optimization for an Italian multi-family building case-study equipped with a solar cooling system. Given a design space defined by set of variables related to Heating, Ventilation and Air Conditioning systems (HVAC) and renewable systems, a machine learning method based on residual neural networks to predict and minimize the objective function characterizing non-renewable primary energy consumptions is proposed. Results have shown that the approach is able to successfully identify optimized design solutions (energy performance improved by 47%) with good prediction accuracy (error smaller than 3%) while reducing the overall computation time and maximizing the exploration of the design space, paving the way for further advancements in simulation-based optimization for NZEB design.

Embargado hasta 23/11/2023 Solar heating ventilating air conditioning systems are useful tools to meet the objectives of the European Commission in terms of sustainability in buildings, since their use can reduce the environmental impact, including CO2 emissions, due to their low energy consumption. In order to quantify the improvement that in environmental terms the use of this type of system could entail, in this work it was carried out (a) a comparative life cycle assessment of a solar heating ventilating air conditioningsystem based on vaporative ooling and desiccant wheel with a conventional direct expansion system; and (b) an analysis of feasible modifications of the desiccant wheel based system and their influence on the life cycle analysis results. The experimental desiccant wheel based system showed a slightly higher environmental performance than the conventional direct expansion based system, between 2% and 10%, for the 3 impact categories evaluated: human health, ecosystem quality and resource consumption. When weight optimisation and the reuse of materials were considered, the environmental performance of the experimental based system became even up to between 22% and 50% higher than that of the conventional direct expansion based system. That involved a 60 % reduction in climate change potential indicator, which mainly was influenced by CO2 emissions.

Rapid urbanization, global warming and enhanced quality of life have significantly increased the demand of indoor thermal comfort and air conditioning systems are not a luxury anymore, but a necessity. In order to fulfil this need, it is imperative to develop affordable and environmentally friendly cooling solutions for buildings. In this work, the 3E performance (energetic, economic and environmental) of electrically driven water-cooled vapour compression systems and thermally (solar) driven vapour absorption cooling systems are evaluated and the parameters affecting the performance of solar-driven vapour absorption systems are investigated. The energy simulation software TRNSYS is used to simulate the performance of both systems in order to fulfil the cooling needs of an industrial manufacturing building for the typical climate conditions for Lahore, Pakistan. Primary energy saving, initial investment, operational cost, and carbon footprint indices are used to analyse the performance of both systems. In addition, a parametric code is written in Python and linked with TRNSYS to perform a parametric study to investigate the effects of various parameters such as solar field size, storage tank volume, optimum annual and monthly collector angles, and flow rate in the solar field on the solar-driven vapour absorption chiller performance. The results reveal that around 5% more energy can be absorbed per collector surface area by changing the solar tilt angle on a monthly basis compared to one fixed angle. The analysis shows that electrically driven vapour compression-based cooling systems have much higher running cost and are potentially hazardous for the environment but have lower capital costs. On the other hand, solar thermal systems have lower running costs and emissions but require further reductions in the capital costs or government subsidies to make them viable.

Final energy consumption in the residential sector is increasing, even in countries with favourable climate conditions and technological capacity to promote the use of renewable resources and energy efficiency. Air conditioning systems based on absorption cycles are common solutions in solar assisted installations. In this paper, the main characteristics of the Gij&oacute, n Solar Cooling Laboratory (GSCL) are summarized, showing its ability to test cooling machines with a variety of heat sources and sinks, as well as different technologies and strategies. An absorption machine with internal energy storage in LiCl salts has been tested at the GSCL, measuring power and temperatures as a function of time during several charging and discharging cycles. During the charging cycles, the operation of the machine was analysed for various hot temperatures and power values. In the discharging cycles, special attention was paid to the refrigeration capacity produced for various chilled water temperatures. The results led to coefficient of performance COP values that are in line with those expected for this technology. Satisfactory operation of the system seems difficult at activation temperatures below 75 &deg, C. For low levels of insolation, this limitation could lead to an increase in auxiliary energy consumption.

&ldquo, Desigrated&rdquo, presented an attempt to integrate heat prevention strategies with low-ex cooling technologies, namely the desiccant and M-cycle evaporative cooling technology, in the form of a fa&ccedil, ade system for high-rise office buildings. The project targets to provide an alternative cooling solution for the hot and humid climate context of Bangkok. The results from experiments by various researchers are used as assumptions in developing the system, which was then evaluated through numerical methods and dynamic simulations. Being one of the prominent dehumidification technologies, a composite silica gel heat exchanger (CCHE) was implemented as the primary part of the fa&ccedil, ade system, while the M-cycle technology would also be implemented as a secondary cooling technique to cool down the supply air. The evaluation shows a promising result with up to 36% energy consumption reduction in comparison with the conventional cooling system, presenting itself as a transitioning tool in order to replace refrigerant cooling.

An important element of a solar installation is the storage tank. When properly selected and operated, it can bring numerous benefits. The presented research relates to a project that is implemented at the Solar Energy Research Center of the University of Almeria in Spain. In order to improve the operation of the solar cooling and heating system of the Center, it was upgraded with two newly designed storage tanks filled with phase change materials (PCM). As a result of design works, commercial material S10 was selected for the accumulation of cold, and S46 for the accumulation of heat, in an amount of 85% and 15%, respectively. The article presents in detail the process of selecting the PCM material, designing the installation, experimental research, and exergy analysis. Individual tasks were carried out by research groups cooperating under the PCMSOL EUROPEAN PROJECT. Results of tests conducted on the constructed installation indicate that daily energy saving when using a solar chiller with PCM tanks amounts to 40% during the cooling season.

The thermoacoustic behavior of different typologies of porous cores is studied in this paper with the goal of finding the most suitable solution for small thermoacoustic devices, including solar driven air coolers and generators, which can be used in future buildings. Cores provided with circular pores, with rectangular slits and with arrays of parallel cylindrical pins are investigated. For the type of applications in focus, the main design constraints are represented by the reduced amount of the input heat power and the size limitations of the device. In this paper, a numerical procedure has been implemented to assess the behavior of the different core typologies. For a fixed input heat power, the maximum acoustic power delivered by each core is computed and the corresponding engine configuration (length of the resonator and position of the core) is provided. It has been found that cores with parallel pins provide the largest amount of acoustic power with the smallest resonator length. This conclusion has been confirmed by experiments where additive manufactured cores have been tested in a small, light-driven, thermoacoustic prime mover.

At present, novel, small-to-large capacity absorption chillers with unique technical features have emerged on the global market, and laboratory and pre-industrial prototypes have also been developed. These chillers have been designed for the efficient use of low-grade heat sources; some are air-cooled, small capacity systems; compact water/LiBr chillers; or solar-gas-fired single/double-effect chillers. Also, some advanced commercial absorption chillers have an extensive temperature glide in the driving heat stream (>30 K) which extracts approximately twice as much heat (~200%) as the single-effect chiller. This large temperature glide means that the chillers are well suited to solar thermal collector installations and district heating networks, and the extra driving heat increases cold production. Moreover, recent advances in R718 turbo compressor technologies have helped to solve the problems water/LiBr absorption chillers have in adapting to extreme operating conditions (e.g., high ambient temperature, >35 °C) by using a compressor-boosted absorption chiller configuration. This review paper presents and discusses the developments and progress in these absorption chiller technologies. In summary, the new absorption chillers may be useful for developing efficient, cost-effective, and robust solar cooling solutions that are needed to mitigate the unsustainable impact of the rising global demand for space cooling.

This paper aims to present a comparative study into the cascade and series configurations of the organic Rankine cycle based small-scale solar combined cooling, heating and power system for civil application. The energy performance of the systems is studied by developing a thermodynamic model. The simulation model is validated using the literature results. Analyses of the research results indicated that the cascade system can achieve maximum value of the primary energy efficiency of 13.4% for cooling and power generation under solar collecting temperature of 115 &deg, C in cooling mode. The cascade system has more cooling output and less electricity output in cooling mode compared with the series system. In heating mode, the single solar organic Rankine cycle (ORC) operation can achieve highest primary energy efficiency of 19.6% for heating and power generation under solar collecting temperature of 100 &deg, C. Systems with R141b as ORC working fluid show better performance than those with R123 and R1233zd(E).

The high environmental impact of conventional methods of cooling and heating has increased the need for renewable energy deployment for covering thermal loads. Towards that direction, the proposed system aims at offering an efficient solar powered alternative, coupling a zeolite-water adsorption chiller with a conventional vapor compression cycle. The system is designed to operate under intermittent heat supply of low-temperature solar thermal energy (

This paper performs technical, economic and environmental feasibility analyses of two different solar cogeneration plants, consisting of a solar system (a parabolic trough collector field coupled with thermal energy storage), an Organic Rankine Cycle (ORC), and mechanical chillers, that should cover the electrical and cooling demands of a commercial center located in Zaragoza (Spain). System A is hybridized with an auxiliary biomass boiler that complements the solar system’s thermal production, providing a constant heat supply to the ORC, which operates at full load during the operating hours of the solar system. In contrast, system B is not hybridized with biomass, so the ORC is fully driven by the solar system, operating at partial load according to the solar resource availability. Both systems are connected to the electrical grid, allowing electricity purchases and sales when needed. The design procedure involves the sizing of the equipment as well as the modelling of the hourly behavior of each system throughout the year. The physical analysis is complemented by an economic assessment, which considers investment and variable costs, as well as an estimate of the significant environmental benefits of the proposed plants. The solar plants are compared to a conventional system in which all the electrical consumption is covered with electricity purchased from the grid. The costs of the electricity produced by systems A and B are estimated at 0.2030 EUR/kWh and 0.1458 EUR/kWh, which are about 49% and 7% higher than the electricity purchase price in Spain (0.1363 EUR/kWh). These results indicate that while none of the solar plants are presently competitive with the conventional system, system B (without biomass hybridization) is actually closer to economic feasibility in the short and medium term than system A (with biomass hybridization).

A large fraction of cooling demand depends on solar radiation intensity, therefore a strong attention was directed toward solar cooling immediately after the 1973 energy crisis. Whereas pilot solar cooling plants were built up and experimented, this technology never really took off. A recent survey reported something more than 1000 plants operating, a very modest number with respect the great potential of solar cooling. A review of technologies as they developed in the past, operate in the present with a forecasting for the future is here proposed to follow how the technology evolved during almost half a century regarding the solar section and the relative refrigeration equipment. The analysis allows to take stock of the situation selecting solar sections, cooling machines and their coupling which seem nowadays more suitable for wide application in the near future. A study is proposed at the end to put together some energy evaluations in different climates and much more difficult economical evaluations to investigate whether a possible fossil fuel parity cost can be attained, if not today, in a near future.

The present paper presents the development of a thermal energy storage system for application with non-concentrating solar plants using phase change materials (PCMs). The outcomes of an experimental analysis on commercial and non-commercial PCMs suitable for the desired temperature range is presented, with main focus on to the enthalpy and the cycle stability of the materials. Particularly, a first evaluation of possible degradation mechanisms in hydrated salts was investigated by means of Nuclear Magnetic Resonance (NMR) spectroscopy. The best performing materials have been implemented in a numerical model, based on the enthalpy method, used for the design of a thermal storage system. The configuration of the system, starting from a simple shell-and-tube layout, has been optimised by inserting asymmetric fin-and-tubes and the results with two selected materials have been compared. The analysis has shown that the most promising materials are the commercial ones belonging to the classes of paraffinic materials and hydrated salts and that, with the designed configuration, it is possible to store up to 200 kJ/m3 and get a peak power during discharge of about 1.5 kW.

Absorption chillers can use waste heat, solar heat, or excess heat by cogeneration facilities to supply chilled water. Therefore, absorption chillers are important components for poly-generation, which can improve plant utilization and efficiency of the overall energy supply system. Currently, 27 new small and medium-scale (30–160 kW cooling capacity) absorption chillers with high efficiency in full- and part-load as well as low specific size and weight are the focus of two research projects sponsored by German Federal Ministries. The chillers are located in 20 different sites, four of them in Jordan and the rest in Germany. The main objective of these projects is to enhance trigeneration and solar cooling system efficiency. The Jordan projects and more than 70% of the German installations use dry cooling towers. Combined heat and power (CHP) plants or district heating grids provide the driving heat for regeneration at the German installations. Solar thermal collectors drive one German and all Jordan installations. Within the projects, the chillers are provided with an intelligent control algorithm that allows achieving several objectives at the same time. One of the objectives, of course, is to match the desired chilled water temperature as well as the cooling capacity. Another objective is, for instance, to fit the hot water outlet temperature. This is commonly essential in cogeneration to avoid emergency shutdowns of the CHP engine. The field operation shows that the deviation of said temperatures from the set point is usually less than ±0.5 K in operation. In those operational hours in which the temperatures of the heat source or heat sink do not allow to reach all objectives, a set of hierarchical aims can be established within the algorithm so that the chiller can be controlled to match its prioritized objectives. Furthermore, the designed absorption chiller performs dynamically and autonomously in a very large range of temperatures and flow rates. These can vary from 20% up to 150% of nominal conditions. This flexibility can be used to achieve up to 80% savings of electrical power consumption using speed-controlled pumps in part load conditions. In contrast to the common opinion that small and medium-scale absorption chillers are not competitive as compared to compression chillers, this paper shows applications in which absorption chillers are advantageous because of synergies with and multiple benefits within the rest of the energy supply system.

Copyright: © 2021 by the authors. In solar-thermal adsorption/desorption processes, it is not always possible to preserve equal operating times for the adsorption/desorption modes due to the fluctuating supply nature of the source which largely affects the system’s operating conditions. This paper seeks to examine the impact of adopting unequal adsorption/desorption times on the entire cooling performance of solar adsorption systems. A cooling system with silica gel–water as adsorbent-adsorbate pair has been built and tested under the climatic condition of Iraq. A mathematical model has been established to predict the system performance, and the results are successfully validated via the experimental findings. The results show that, the system can be operational at the unequal adsorption/desorption times. The performance of the system with equal time is almost twice that of the unequal one. The roles of adsorption velocity, adsorption capacity, overall heat transfer coefficient, and the performance of the cooling system are also evaluated. Iraqi Ministry of Higher Education and Scientific Research / Research and Development Department / Program of Renewable and Sustainable Energy Projects, grant number 1613.

The result of the joint efforts of University of Bergamo and Mohammed Bin Rashid Space Centre (a Dubai Government institute) is the first Energy+ building in Dubai, virtually off-the-grid and PassivHaus certified. The present work deals with the computer models developed to predict the energy performance and to guide the design choices of the two floor office building unveiled to the public in November 2016. Trnsys software has been used to revise and validate the architectural ideas and the energy design.

This paper seeks to present a panorama of cooling related research in office buildings, categorising reported research experiences from the past 25 years in order to identify knowledge gaps and define current paths and trends for further exploration. The general goal behind this research is to support the design of sustainable office buildings in warm climates through examination of past experiences, thus the paper focuses on strategies at building level and specially related with façade design. Peer reviewed journal articles were selected as the source for the study, given the reliability of the information published under peer-review processes. Several queries were carried out throughout three online journal article databases (Web of Science, SCOPUS and ScienceDirect), considering published papers from 1990 onwards. The resulting article database was then explored trough descriptive analysis and in-depth review of some articles to expand on specific topics in order to thoroughly visualise scientific interest and tendencies within the field of study for the last 25 years. As results of the review it is possible to state the high current relevance of cooling research, having experienced an increase of publications under different climate contexts and varied topics ranging from passive to solar cooling, which is seen as a research field on its own. Also, in terms of research methods, software simulations seem to be the primary tool for cooling research, which makes sense for performance driven developments. On the other hand, the main knowledge gaps identified are the need for specific research regarding possibilities for application and architectural integration of cooling systems; the lack of articles addressing some specific cooling strategies, such as the use of evaporative and ground cooling; and the need for more information about the operation of cooling systems, especially taking users’ perception and their behaviour into account.

Solar cooling technology is an attractive way to use solar thermal energy to produce cooling for buildings. The employment of taphase change materials (PCMs) as heat storage medium, to increase the range of utilization of solar thermal energy, thus improving the overall system performance, is considered very attractive. Nevertheless, in order to allow the development of latent heat storage prototypes for such an application, it is mandatory to verify the thermo-physical performance as well as the long-term stability of the available materials. To this aim, in the present paper, the most attractive commercial PCM as well as neat chemical compounds operating in the temperature range between 80 °C and 100 °C, perfectly suitable for non-concentrating solar cooling systems, have been identified and completely characterized. In particular, several cycles have been performed on each material, to verify possible instabilities in their behavior. Most of the neat materials have confirmed to be promising for this application, thanks to their really high melting enthalpy, up to 255 J/g as showed for Aluminum Ammonium Sulfate Dodecahydrate. Nevertheless, all these materials are still not stable, showing high supercooling, allotropic phase transition, incongruent melting and even absence of re-crystallization, which makes necessary an intense work to bring them to a reliability level sufficient for real application. On the contrary, the commercial PCMs, even if mostly characterized by lower melting enthalpy, ranging between 120 and 150 J/g, confirmed their stability, which makes them ready for practical applications.

There are various factors having an impact on the energetic and exergetic performance (i.e., COP and eCOP) of an absorption refrigeration systems (ARS) such as the temperatures of the generator, condenser, evaporator and absorber, effectiveness of solution, refrigerant and solution-refrigerant heat exchangers and isentropic efficiency of the solution pump. Many studies have focused on these process parameters, but the importance order and contribution ratios of the parameters due to thermodynamic performance have not been determined by using statistical methods. Firstly, in this study, cycles’ thermodynamic model is established and the variation of the COP and eCOP are calculated for different working conditions with different parameters ranges. The effects of these parameters on the COP and eCOP are examined separately on a statistical basis. The importance order of the parameters are determined by using Taguchi and ANOVA methods and the results are compared. Optimum operating conditions are determined by means of statistical analysis for the COP and eCOP. Under these operating conditions, the COP and eCOP of the system are calculated as 0.697 and 0.2829, respectively. Furthermore, for the simultaneous maximization of these two performance indicators, Taguchi-Grey Relational Analysis (GRA) is used. By using this analysis, importance order of the examined parameters on multiple performance characteristics are determined. The absorber and evaporator temperatures are the most efficient parameters on multiple performance characteristics with a contribution ratio of 29.66% and 26.34% of the total effect while the least efficient parameters are the pump efficiency and effectiveness of solution-refrigerant heat exchanger with a contribution ratio of 0.48% and 2.41%, respectively. For the best condition considering the multiple performance characteristics, COP and eCOP of the system are found as 0.6255 and 0.2829, respectively.

Reduction of the green-house effect can be obtained by reducing the emissions of CO2. One of the technologies that contributes to this purpose is using solar cooling systems. An example of such systems is Lithium Bromide Absorption Chillers-Driven by Hot Water (LiBr/H2O absorption chillers). These chillers are normally powered by solar collectors (ordinary plate or evacuate tubular), which are widely accessible. This paper includes a review of previous experimental and theoretical studies on the effect of single cooling absorption systems. In addition, new proposals regarding the design of the solar collectors, supporting systems for energy and cooling methods will be provided. Furthermore, the present paper also summarizes the major double influence of the cooling absorption systems, add to the two-stage and half-effect absorption coolers. The influence of double cooling absorption systems using solar power could be considered for the buildings with more cooling capacity requirements, but with structure of space restrictions. However, for these cases is important to consider the direct irradiation, which needs high levels. For dry regions with water shortage, half-absorption and two-stage absorption coolers are more suitable. Solar-powered cooling systems designs should follow and incorporate standard rules based on the characteristics of various areas in order to be applicable on a large scale.

In this paper, the activity carried out within the H2020 project ZEOSOL is introduced. Making use of the lessons learned from previous solar cooling projects, an advanced hybrid solar cooling system was developed. It consists of a thermal and an electric unit in parallel integrated in a single unit with the drycooler. ZEOSOL is based on commercial components but was optimised in order to guarantee optimal seasonal performance, high reliability (and therefore reduced maintenance) and easy installation. The components of the system were experimentally tested in the laboratories of AkoTec, CNR ITAE and Fahrenheit, with a specific attention to the definition of performance maps as a function of operating and design parameters. During the tests of each component, possible control strategies and rules were identified. Subsequently, a simplified sizing tool was developed, which can be adapted to different configurations and climates and takes into account user-experience for different stakeholders, such as engineers and installers. The methodology implemented is described, in order to be used as a guideline for the definition of standard sizing procedures for solar cooling systems. As exemplary cases, the results for three different climates (Athens, Berlin and Ryiad) are also presented.

Producción Científica, In this work, we present an absorption cooling system with 35 kW capacity driven by solar thermal energy, installed in the school of Puertecitos, Mexico, an off-grid community with a high level of social marginalization. The cooling system provides thermal comfort to the school’s classrooms through four 8.75-kW cooling coils, while a 110-m2 field of evacuated tube solar collectors delivers the thermal energy needed to activate the cooling machine. The characteristics of the equipment installed in the school were used for simulation and operative analysis of the system under the influence of typical factors of an isolated coastal community, such as the influence of climate, thermal load, and water consumption in the cooling tower, among others. The aim of this simulation study was to determine the best operating conditions prior to system start-up, to establish the requirements for external heating and cooling services, and to quantify the freshwater requirements for the proper functioning of the system. The results show that, with the simulated strategies implemented, with a maximum load operation, the system can maintain thermal comfort in the classrooms for five days of classes. This is feasible as long as weekends are dedicated to raising the water temperature in the thermal storage tank. As the total capacity of the system is distributed in the four cooling coils, it is possible to control the cooling demand in order to extend the operation periods. Utilizing 75% or less of the cooling capacity, the system can operate continuously, taking advantage of stored energy. The cooling tower requires about 750 kg of water per day, which becomes critical given the scarcity of this resource in the community., CONACYT-SENER-SUSTENTABILIDAD ENERGÉTICA (project P09), Programa Iberoamericano de Ciencia y Tecnología para el Desarrollo (project 518RT0558)

This work presents the measured performance data related to the very-first Energy+ building in Dubai certified by the Passive House Institute. The building is a two-floor office structure, with 550 m2 total surface, designed under the guide and the scientific supervision of a Bergamo University research group, jointly to the Mohammed Bin Rashid Space Centre (MBRSC). The goal of the project was to assure a high level of internal comfort all over the year by using only solar energy. The building architecture has been designed to minimize the cooling load and the energy demand. The energy system is based on a 40 kWp PV field coupled with a 48 kWh electric storage and a high-efficiency chiller (reversible heat pump). Transient simulations by Trnsys code have been carried out to optimize both the thermal envelope and the energy plants so to make the building energy-autonomous 24/7. The numerical predictions of the energy performance (including cooling load, PV production and power consumption for chiller, lighting and appliances) are compared to the real data measured by a sophisticated monitoring system, including sensors located in the roof, in the external walls and in the energy systems. The field measurements confirm that the model predictions were accurate both in terms of peak and annual values. The small variations between prediction and real data show that both thermal envelope and PV field perform better than expected. This building is a pioneering pilot-project: the goal was to show that new sustainable construction standards using only solar energy are possible in the United Arab Emirates (UAE) and that this is a viable solution to reduce the carbon footprint in all the Gulf region. The strategic importance of an accurate modeling activity leading to an optimal design has been proved. The monitored data under real operating conditions have confirmed that the expected targets in terms of energy savings and carbon footprint reduction have been successfully achieved.

Adsorption cooling systems (ACS) may contribute towards a sustainable way of satisfying the increasing cooling demand, as they utilize solar thermal energy and employ non-ozone-depleting substances. Apart from the intrinsic ACS performance, the successfulness of its operation depends on its integration within the entire thermal system (solar collectors, thermal storage and building), which is not straight-forward due to thermal inertia effects and its inherent cyclic operation. Numerical simulations can contribute in understanding the system behavior, its adequate dimensioning and the implementation of optimized control strategies. A computational model was developed, capable of performing conjugate, dynamic simulations of the entire thermal system. The influence of the control criteria is investigated and quantified through three simulation phases, conducted for various solar collectors areas and storage volumes. Higher solar fraction is achieved for lower auxiliary heater activation temperature and lower temperature difference activation of the solar pump. Subsequently, simulations with variable cycle duration were performed, using optimized cycle duration according to the instantaneous operating temperatures. This approach reduces significantly the auxiliary consumption or satisfies the demand with less solar collectors. The potential CO 2 emissions avoidance is calculated between 28.1–90.7% with respect to four scenarios of electricity-driven systems of different performance and CO 2 emission intensity.

In many countries, solar cooling systems are one of the best candidates to tackling global warming and summer peak loads of building air conditioning systems. In this work, based on the collaboration with the Saudi research institute “King Abdullah City for Atomic and Renewable Energy”, two types of solar driven cooling systems are investigated and compared: the open-circuit Desiccant Evaporative Cooling technology and the system based on single-stage LiBr absorption chillers. A computer code has been developed in Trnsys® to simulate a well-insulated single-family residential building, starting from a 3D model of the building architecture, and the solar cooling systems. The simulations have been carried out for two different locations: one in a dry desert area (Riyadh, KSA), the other one on the seaside (Abu Dhabi, UAE). The results show that absorption chillers need a very effective heat rejection system to work properly, whilst DEC systems exhibit a dramatic performance reduction in wet climates.

This paper presents an innovative system for solar thermal process steam and chilled water production. The system consists of a 2-stage solar thermally driven steam jet ejector chiller with latent heat and cold storage driven by motive steam from evacuated tube collectors with compound-parabolic-concentrator (CPC-collectors). Within this paper the design and the functionality of the demonstration plant and essential aspects of the system control are discussed. In addition, operational experiences, the operational behaviour of the entire system as well as performance figures are presented and evaluated.

Double-lift absorption cycles represent a suitable solution for air-cooled thermally driven cooling applications. Among the several existing double-lift configurations, semi-GAX cycles are known as the most promising in terms of efficiency. These cycles incorporate the GAX effect in a pressure staged cycle, by means of a split on the solution leaving the low pressure absorber. Two configurations of the semi-GAX cycle have been proposed in the past, the semi-GAX 1 and the semi-GAX 2. The former achieves the GAX effect between the intermediate and the high pressure levels, the latter between the low and the intermediate. Within this paper, the semi-GAX cycles are numerically investigated at operating conditions suitable for a low temperature driven (e.g., by flat plate solar collectors) air conditioning application. The peculiarities of the two cycles are described and the factors affecting their performances are underlined. The COP resulted to be strongly influenced by the split ratio, which determines the intermediate pressure and the possibility to achieve the GAX effect. If the split ratio is optimized to achieve the maximum COP, the COP is higher for semi-GAX 2 for air temperatures below 27 °C and for semi-GAX 1 above. In both cases, the maximum air temperature which allows a circulation ratio below 15 is 40 °C, with chilled water at 7/12 °C and driving temperature of 90 °C.

The paper investigates the introduction of a solar heating and cooling system in an office building characterized by low energy demand with respect to the current national building stock and located in Southern Italy. Dynamic simulations are carried out in order to evaluate the thermo-economic performance of the analyzed system considering different solar panel technologies (flat plate and evacuated tube), tilt angles (10–70°), collecting areas (30–60 m 2 ), hot and cold storage sizes, reference emission factors, electricity and natural gas unitary prices. To satisfy cooling demand a small scale adsorption chiller activated by thermal energy available from solar collectors is considered. The solar heating and cooling system demonstrated primary energy saving and equivalent dioxide carbon emission reduction higher than 23% in comparison to the reference conventional system. The results show that the solar energy system will be competitive when the electricity and natural gas prices will be high and strong government incentives will be provided.

Solar thermal cooling technology is currently facing a very exciting challenge. Air conditioning is a large and growing energy consumer, especially in sunny and developing countries. Worldwide efforts to develop renewable energy solutions must address this critical cooling application. Solar thermal energy presents a natural and strong opportunity to do just this. However, even if reliable technologically advanced products are presently available, the solar cooling sector must leap from a pre-industrial and demonstration status into a competitive mass market. Despite this, some applications, particularly for large buildings with combined cooling and domestic hot water production, are already very close to cost competitiveness without any incentives. This paper will concentrate on introducing an international collaborative R&D activity called IEA SHC Task 48 in the field of solar cooling and the methodology, participating entities and initial outcomes.

Within IEA-SHC Task 48 “Quality assurance and support measures for Solar Cooling” the most crucial components of solar thermal cooling plants have been analyzed in detail aiming at improving their quality. Test procedures for characterizing continuous and discontinuous chillers have been developed; market available heat rejection devices have been investigated, rating their performance through monitoring data and comparing them; pump efficiency has been also investigated and design guidelines for pump selection and hydraulic configuration are now available; a detailed and updated database of medium temperature collectors has been built.

This paper presents the possibility of reducing the demand for nonrenewable primary energy for buildings using a new conceptual adsorption system of cooling and heating supplied by solar energy. Moreover, the aim of this study is to shorten the payback time of investment in the standard adsorption cooling system through its integration with the heating system. Research has been carried out for an energy-efficient medium-sized single-family building with a floor area of 140 m2 and a heat load of 4.2 kW and cold load of 4.41 kW. It has been shown that the use of an adsorption system of cooling and heating supplied by solar energy decreased the demand for nonrenewable primary energy by about 66% compared to the standard building that meets the current requirements.

The greenhouses cultivation causes in summer season inner conditions characterized by high thermal levels such as to generate problems that can damage crops. Always more frequently for this reason it is common to provide greenhouse with air conditioning plants. In this work it will be presented an application of a solar cooling plant with absorption cooling machine for thermal control of a greenhouse and an advanced simulation model able to evaluate optimal plant configurations and controls. Solar cooling systems can be applied for greenhouse climate control in regions with high values of solar irradiation as alternative to traditional evaporative systems, allowing the reduction of primary energy consumption by exploiting the contemporaneity between the cooling requirements and the solar energy availability. The plant consists of a single effect LiBr-H2O absorption chiller fed by evacuated-tube solar collectors; the model was developed in Matlab-Simulink and is able to simulate dynamically, with time steps up to 15 minutes, the greenhouse cooling demand and the production of the solar field. Present study proposes a plant configuration with a distribution system in which the cooling power is not provided for the entire volume of the greenhouse, but only for the air volume surrounding the crop with a considerable saving of reduction of energy demand and an extremely efficient use of solar energy. The simulation study is based on the experimental data collected at the experimental center of the University of Bari, Southern Italy. The aim of the work is to demonstrate that solar cooling system could provide significant energy-saving opportunities for cooling greenhouses allowing the reduction of primary energy consumption by exploiting the contemporaneity between the cooling requirements and the solar energy availability.

The main objective of this study was to investigate the effect of inlet temperature (Tin) and flowrate ( m ˙ ) on thermal efficiency ( &eta, t h ) of flat plate collectors (FPC). Computational Fluid Dynamics (CFD) was employed to simulate a FPC and the results were validated with experimental data from literature. The FPC was examined for high and low level flowrates and for inlet temperatures which varied from 298 to 373 K. Thermal efficiency of 93% and 65% was achieved at 298 K and 370 K inlet temperature&rsquo, s respectively. A maximum temperature increase of 62 K in the inlet temperature was achieved at a flowrate of 5 &times, 10&minus, 4 kg/s inside the riser pipe. Tin and m ˙ were optimised in order to achieve the minimum required feed temperature for a 10 kW absorption chiller.

Research into photovoltaic thermal systems is important in solar technologies as photovoltaic thermal systems are designed to produce both electrical and thermal energy, this can lead to improved performance of the overall system. The performance of photovoltaic thermal systems is based on several factors that include photovoltaic thermal materials, design, ambient temperature, inlet and outlet fluid temperature and photovoltaic cell temperature. The aim of this study is to investigate the effect of photovoltaic thermal outlet water temperatures and solar cell temperature on both electrical and thermal efficiency for different range of inlet water temperature. To achieve this, a mathematical model of a photovoltaic thermal system was developed to calculate the anticipated system performance. The factors that affect the efficiency of photovoltaic thermal collectors were discussed and the outlet fluid temperature from the photovoltaic thermal is investigated in order to reach the highest overall efficiency for the solar cooling system. An average thermal and electrical efficiency of 65% and 13.7%, respectively, was achieved and the photovoltaic thermal mathematical model was validated with experimental data from literature.

Small-scale systems and integrated concepts are currently being explored to promote the widespread application of solar cooling technologies in buildings. This article seeks to expand application possibilities by exploring the feasibility of solar cooling integrated fa&ccedil, ades, as decentralized self-sufficient cooling modules on different warm regions. The climate feasibility of solar electric and solar thermal concepts is evaluated based on solar availability and local cooling demands to be met by current technical possibilities. Numerical calculations are employed for the evaluation, considering statistical climate data, cooling demands per orientation from several simulated scenarios, and state-of-the-art efficiency values of solar cooling technologies, from the specialized literature. The main results show that, in general, warm-dry climates and east/west orientations are better suited for solar cooling fa&ccedil, ade applications, compared to humid regions and north/south orientations. Results from the base scenario show promising potential for solar thermal technologies, reaching a theoretical solar fraction of 100% in several cases. Application possibilities expand when higher solar array area and lower tilt angle on panels are considered, but these imply aesthetical and constructional constraints for fa&ccedil, ade design. Finally, recommendations are drafted considering prospects for the exploration of suitable technologies for each location, and fa&ccedil, ade design considerations for the optimization of the solar input per orientation.

The paper mainly deals with the match of solar refrigeration, i.e., solar/natural gas-driven absorption chiller (SNGDAC), solar vapor compression–absorption integrated refrigeration system with parallel configuration (SVCAIRSPC), and solar absorption-subcooled compression hybrid cooling system (SASCHCS), and building cooling based on the exergoeconomics. Three types of building cooling are considered: Type 1 is the single-story building, type 2 includes the two-story and three-story buildings, and type 3 is the multi-story buildings. Besides this, two Chinese cities, Guangzhou and Turpan, are taken into account as well. The product cost flow rate is employed as the primary decision variable. The result exhibits that SNGDAC is considered as a suitable solution for type 1 buildings in Turpan, owing to its negligible natural gas consumption and lowest product cost flow rate. SVCAIRSPC is more applicable for type 2 buildings in Turpan because of its higher actual cooling capacity of absorption subsystem and lower fuel and product cost flow rate. Additionally, SASCHCS shows the most extensive cost-effectiveness, namely, its exergy destruction and product cost flow rate are both the lowest when used in all types of buildings in Guangzhou or type 3 buildings in Turpan. This paper is helpful to promote the application of solar cooling.

Convective heat transfer can be enhanced passively by using fluids with high value of the thermal conductivity. An innovative method of enhancement of thermal conductivity of base fluids is to insert nanoparticles. In recent years, nanofluids and their possible applications have been extensively studied. In this study, simulation based on a performance analysis of a solar cooling system is carried out by means of TRNSYS. First the analysis determines the peak energy demand for a building located in Naples. Beside, for the same configuration of solar system both pure water and Al2O3/water based nanofluids are considered as working fluids. Different values of volume nanoparticles concentrations, equal to 3%, and 6%, are investigated. The configuration is fully modelled in TRNSYS and dynamic simulations are run for the entire year. Various performance factors such as useful energy gain from collector, solar fraction, primary energy savings and pumping consumption are evaluated. Simulations results demonstrate that for the whole summer season, using nanofluids as working fluid, always higher primary energy savings results. Besides, solar fraction, difference between nanofluids with nanoparticles concentration of 3% and 6% is estimated to be marginal. In terms of PEC and primary energy savings, nanofluids with nanoparticles concentration of 6% has presented higher values.

This work presents the performance analysis of the very first Energy+ building in Dubai certified by the German Passive House Institute. The analysis is presented as comparison between numerical predictions and the first available monitored data. Trnsys is the software used to create the energy model, including both thermal envelope and HVAC system. The use of highly insulating materials, together with a design aimed to reduce the solar heat gains, allows for minimizing cooling loads. A 40 kW PV field, coupled to a 25 kWh battery storage and to a high-efficiency air-cooled electric chiller, fulfills the electric and cooling demand, making the building energy-autonomous. The study demonstrates the high accuracy of the energy model, able to predict precisely the building cooling loads, the energy production and the cooling system performance. The Energy+ building, inaugurated in November 2016, is a pioneering pilot-project and it represents an advance in the field of sustainable construction for all Arabic area.

International audience; This paper presents a smart design named PV COOLING to produce solar cooling using low GWP heat pump system coupled with a standard photovoltaic plant. A maximum of self-consumption is promoted by means of a light bank of batteries and chilled water tank. For this, a test bench has been installed on the building roof in the south of France with the originality to be entirely controllable in terms of building load injected. Thereafter, this new system aims to be used for airconditioning and/or dehumidification in the tertiary sector and positive cold storage in the industrial sector in countries where climatic, regulatory and technical conditions are suitable. PV COOLING potential is developed within a market study. The aim of this study is to assess the thermal / electrical performances of our test bench with the purpose to airconditioning a building by means of several sensors and meters.

This paper presents the design and performance analysis of a solar thermal heating and cooling (SHC) system. Apart from year-round domestic hot water (DHW) heating and space cooling, the specific system design provides the possibility to utilize waste heat of absorption chiller (ACH) during cooling operation for DHW preheating. This system was designed and set up as a first pilot plant on northern Adriatic coast of Croatia to ensure better assessment of technical and economic feasibility of SHC systems in that area through monitoring during operation. Following the system configuration design with original control system parameters, a detailed TRNSYS dynamic simulation model is developed. A methodology for validation of simulation model on a level of complete SHC system is proposed. The presented approach comprises simulation of the control system and interaction between system components, thus enabling reliable application of simulation model for further improvements of a particular system. Monitoring and simulation data showed satisfactory performance of SHC system. 55% of total irradiated solar energy is utilized at solar collectors, measured seasonal chiller efficiency ratio is 0.68 and running costs are 0.0225 € per kWh of produced cooling energy. Monitoring data also indicated that, due to unexpected low DHW consumption of the particular system compared to design guidelines, only 8% of heat from condenser and absorber is recovered, while the rest of the heat is rejected to surroundings at the cooling tower. Using the simulation model, a set of scenarios with increased DHW consumption and improved heat exchanger parameters were investigated in order to overcome the issue of low heat recovery efficiency. Preliminary analysis for analyzed period showed possibility for recovery up to 53% of waste condenser and absorber heat, reduction of cooling energy price by 15% and reduction of total system running costs when heating and cooling are both considered. The developed simulation model has been proven as valuable tool for evaluation of energy balances and feasibility analysis as well as for system configuration analysis and performance enhancement and it will be used for further research in order to achieve optimal efficiency in year-round operation.

In last decades, much effort has been made to drive cooling cycles exploiting renewable energy sources. The use of solar energy is one of the most attractive solutions especially for air conditioning, as availability of solar radiation and cooling loads are approximately in phase. Solar cooling based on water-lithium bromide absorption chillers is the most promising technology for low-medium temperature heat sources (80-100 °C). Small (15-40 kW cooling capacity), medium (50-250 kW) and large scale (up to tens of MW) units are currently at commercial stage. In the present work, the development of a novel micro-scale LiBr absorption chiller (around 5 kW) is presented. The objective is to demonstrate the technical feasibility and to investigate the performance under different operating conditions. A computer code has been developed to simulate a LiBr absorption chiller. The model computes mass flow rates, temperatures, pressures and mass concentration of LiBr-water solution in all the chiller components, both in design and off-design conditions. Giving as inputs inlet temperature and mass flow rate of the external circuits (hot water source, cooling water and chilled water), the computer code is able to evaluate the efficiency (COP) and the actual cooling capacity. The simulation code has been used to size the heat exchangers and to design a prototype of a micro-scale chiller. The chiller prototype with a 5 kW nominal cooling capacity has been manufactured and fully instrumented in order to monitor all physical quantities in the internal and external circuits. The prototype is installed on a test rig at the Energy System and Turbomachinery Laboratory of Bergamo University. Measurement devices, data acquisition system and in-house monitoring software are described in the paper. Preliminary results of the experimental investigation are presented.

The paper reports the preliminary experimental results of an hybridization between a classic ventilated facade and photo-voltaic panels powering a Peltier cells system to improve the inner summer comfort with an environmental friendly approach. The outer layer of the facade is made of photovoltaic panels while a pair of light alloy heat exchanger, coupled on the opposite sides of the Peltier cells, are fitted between the internal space and the air chimney of the facade. The Peltier cells are electrically wired directly with the solar cells: the more the sun affects the front, the more the solar cells produce power to feed the Peltier cells that work as a static heat pump, cooled by the air flowing through the interspace of the ventilated facade. This will result in an inside cooling effect and this effect shall be summed with the well-known passive good performance of the ventilated facade in summer sunny days. During the winter, a simple switch of the power polarity would result in a free inner heating effect, partially using the solar energy incident on the front: the risk of icing on the cold exchanger in the chimney would be reduced because of the heat transmitted by the rear side of the photo-voltaic cells. A small scale prototype has been tested during summer, showing an improvement of the inner air temperature of about 3-4 K during the sunniest hours, in comparison with the unequipped case.

In hot dry climates, due to the high demand for space air conditioning during summer and the abundance of solar radiation, solar air conditioning is a promising approach to reduce the energy consumption and negative environmental impact of buildings. Solar cooling systems have used various types of collectors to drive chillers. In this paper, a salinity gradient solar pond is suggested as a collector to drive an absorption chiller, to provide cool air for a house during hot and dry weather. A coupled simulation between MATLAB and TRNSYS has been used to solve the problem. MATLAB code was written to solve the governing equations for the salinity gradient solar pond and the ground underneath it. TRNSYS software was used to model the solar cooling system including the absorption chiller and building. The weather data used was for Baghdad in Iraq. It was found that the salinity gradient solar pond could be used to drive the absorption chiller and produce cool air for a single family house during the summer period. Different solar pond areas were tested with the same chiller capacity. It was found that a solar pond area of approximately 400 m 2 was required to provide satisfactory cooling for a typical house with a floor area of approximately 125 m 2 .

This article describes the development of the SolabCool®. The SolabCool® is an air-conditioning unit for one family dwellings and or small offices. It is based on solar or waste heat driven adsorption cooling. The process is intermittent, so 2 tanks with silica gel at reduced pressures are used. To make the machine cost-effective and easy to use, two completely new valves were developed, patented and implemented, in combination with an advanced control unit. A pilot manufacturing plant is in operation since end of 2013. The first modules were produced and tested. The maximum so-called cold factor for the SolabCool® is 0.55. The cold factor is rather stable at a large variety of operation conditions, i.e. climate conditions. This is a very good result compared to other semi-intermittent air-conditioners. Demonstration in the market in The Netherlands started in 2014. The design freeze of the SolabCool® is carried out in the summer of 2014 and the pilot production will start.