Search

Solar heating and cooling (SHC) systems are currently attracting attention, especially in times of increasing energy prices and supply crises. In times of lower energy prices, absorption SHC systems were not competitive to compression cooling supported by photovoltaic (PV) modules due to the high investment costs and total energy efficiency. This paper aims to discuss the current changes in energy supply and energy prices in terms of the feasibility of the application of a small absorption SHC system in a mild Mediterranean climate. The existing hospital complex restaurant SHC system with evacuated tube solar collectors and a small single-stage absorption chiller was used as a reference system for extended analysis. Dynamic simulation models based on solar thermal collectors, PV modules, absorption chillers and air-to-water heat pumps were developed for reliable research and system comparison. The results showed that primary energy consumption in SHC systems designed to cover base energy load strongly depends on the additional energy source, e.g., boiler or heat pump. Absorption SHC systems can be price competitive to air-to-water heat pump (AWHP) systems with PV collectors only in the case of reduced investment costs and increased electricity price. To reach acceptable economic viability of the absorption SHC system, investment price should be at least equal to or lower than a comparable AWHP system.

The paper presents an experimental investigation of a solar dish concentrating system with thermal collectors, along with a numerical investigation of a solar cooling installation based on such system by means of dynamic simulation. The main aim of this study is the analysis of heat generation from the system for heating and cooling purposes, with the use of sorption chillers. A computer simulation of the dynamic operation of the proposed solar heating and cooling system was developed within TRNSYS software. The experimental data were used to validate the model of the concentrator and solar collectors. Successively, a solar heating and cooling installation for a residential application, integrating the different configurations of solar energy collecting devices and thermally driven chillers, was proposed and dynamically simulated. Flat-plate, evacuated tube and photovoltaic-thermal collectors were considered along with absorption and adsorption chiller units. In the present study, different system configurations, localities and time bases were considered to investigate the energy and economic performance of the system. The model of the solar dish and collector arrangement overestimates the produced energy by less than 5% as compared to the experimental study. The results show that the space cooling demand is matched in 23.6 and 46.2% by solar energy in Warsaw, while in Lisbon from 38.2 to 46.1%. The simple payback period of the investigated system configuration was for Warsaw between 18.1 years for the combination of flat-plate collector and absorption chiller and 27.2 year for the photovoltaic-thermal collector with adsorption chiller.

Solar heating and cooling systems are a promising technology which may significantly contribute to the reduction of greenhouse gas emissions, the enhancement of energy efficiency, and the increase of renewables share in the building sector. The available literature show a high number of papers aiming at investigating solar heating and cooling systems based on heat driven and solar technologies, configurations, operating strategies, and financing issues. Nevertheless, none of the papers available in literature investigates the possibility to replace conventional solar thermal collectors by flat plat and concentrating photovoltaic/thermal systems, also producing renewable electricity. To cover this lack of knowledge, in this paper a dynamic simulation model of novel solar polygeneration heating and cooling systems is presented. Such dynamic simulation model is developed and implemented in a computer code, written in MatLab, and allows investigating the energy, economic and environmental performance of such novel solar polygeneration systems, based on both adsorption and absorption chiller technologies fed by dish-shaped concentrating and flat photovoltaic/thermal collectors. In order to show the potentiality of the presented tool, a comprehensive parametric case study is carried out to find out the optimal system configurations, as a function of crucial design and operating parameters and of weather conditions. The presented case study analysis refers to a small cluster of four buildings, including office and residential spaces, located in different European weather zones. The modelled solar polygeneration systems simultaneously produce electricity, space heating and cooling, and domestic hot water; electricity is self-consumed or delivered to the electrical grid. For comparative purposes, two different back-up system configurations, based on an electric chiller and a condensing gas-fired heater are also taken into account as conventional reference building-plant systems. By means of this systematic parametric analysis, comprehensive guidelines for system designers, practitioners and/or researchers focused on the development and use of solar heating and cooling systems are provided.

The yearly thermo‐economic performance is dynamically investigated for three solar heating and cooling systems: solar heating and absorption cooling (SHAC), solar heating and ejector cooling (SHEC), and heating and solar vapor compression cooling (HSVC). First, the effects of important design parameters on the thermo‐economic performance of the systems to supply the heating and cooling loads of the building are evaluated. The systems are parametrically analyzed with the weather conditions of Tehran, Iran. The results show that the life cycle costs (LCC) of the SHAC and HSVC systems are alike and much lower than those of the SHEC system. The HSVC system exhibits the best performance from exergetic and solar fraction viewpoints. The comparative analysis shows that the energy efficiencies of the SHAC and SHEC systems are higher in colder climatic conditions. However, the collector efficiency of the HSVC system declines in colder climates, mainly due to the lower solar intensities relative to in hotter climates. Further, the solar fraction of the SHAC system is higher than the SHEC technology under all climatic conditions. Moreover, higher values of solar fractions are obtained under colder weather conditions for the SHEC and HSVC systems. The best economic performance is observed for the SHAC and HSVC technologies, having significantly lower LCCs than the SHEC system. These lower LCCs under colder climatic conditions are due to the lower cost of supplying the heating load compared to the cooling load. Furthermore, all systems exhibit enhanced exergetic performance in colder weather conditions. The yearly thermo‐economic performance is dynamically investigated for three solar heating and cooling systems: SHAC, SHEC, and HSVC. In addition, the effects of important design parameters on the thermo‐economic performance of the systems to supply the heating and cooling loads of the building are evaluated.

Energy needs of air conditioning systems are constantly growing worldwide, due to climate change and growing standards of buildings. Among the possible systems, solar heating and cooling based on reversible heat pumps and thermally driven chillers are a viable option for ensuring space heating and cooling for different users. The high installation costs are a limit to their diffusion, however, under specific circumstances (climate, type of the building, type of the user, etc.), the investment in this technology can be profitable in a long term. The presented paper describes an energy-economic assessment of a solar heating and cooling system integrating a solar dish concentrator with thermal collectors coupled with a reversible heat pump and an absorption or adsorption chiller. The system integrated with a household building is developed and dynamically simulated in the Transient System Simulation (TRNSYS) environment under different circumstances –adoption of absorption or adsorption chiller, use of auxiliary thermal energy to drive the sorption chillers, and locality. The results show that space cooling demand in Cracow is matched by solar energy, in a range between 49.0 and 97.6%, while for Naples the space cooling demand is provided by solar heat from 46.1 to 99.1% depending on the adopted sorption chiller and or the use of auxiliary heat for a natural gas boiler. The proposed system is not profitable in case Cracow, since a Simple Pay Back period of about 20 years is achieved. Conversely, case of Naples, the same index achieves a value between 8 and 12 years showing that the proposed system may be a viable solution for heating and cooling installation.

8th World Conference on Photovoltaic Energy Conversion; 1331-1335, To tackle the challenges of global warming, efficient design of renewable energy systems is needed. To achieve this goal there is a need of accurate simulations considering uncertainties such as future solar resources. Within the present paper, some of the impacts of future weather scenarios on solar heating and cooling are evaluated. Transient simulations are carried out for different future scenarios to evaluate the impact of the weather data on the energetic efficiency of a PV heat pump system delivering heating, cooling, domestic hot water, and electricity to a multi-family residential building. The system efficiency of different future scenarios is assessed based on the grid purchase ratio. The results show that the overall grid purchase ratio is likely to decrease in the future for the location of Zurich Switzerland, which is mainly caused by an increase in cooling demand during summer due to rising temperatures that come together with high irradiation.

Phase change materials (PCMs) have already been used in buildings and building services for several decades, mostly integrated into walls or ceilings to passively increase the building’s thermal inertia, or integrated into the HVAC system for (pre-)heating or (pre-)cooling fresh air. More recently, the use of PCMs in facades is being explored for solar heating. This paper presents the results of a several years of research into the use of PCMs in rotatable Trombe walls and sun-shading for passive heating and cooling purposes. Simulations used a custom-made model of a room in Matlab/Simulink, in which all relevant heat transfer paths and mass components are accounted for. Once the behaviour of PCM was modelled, the model was connected with the optimisation platform modeFRONTIER to study the (best) performances under different scenarios. The results show that a significant reduction in the energy demand for heating and cooling can be achieved in different climates. The results also show that the shading and insulating effect of the solar wall have the highest impact on the reduction of the cooling respectively heating demand, followed by the thermal mass effect. The paper ends with the development of a prototype of a Trombe wall which was installed in an office at the Green Village (a living lab in Delft)., CLIMA 2022 conference, 2022: CLIMA 2022 The 14th REHVA HVAC World Congress

In this paper a new simulation model of a novel solar heating and cooling system based on innovative high temperature flat plate evacuated solar thermal collector is presented. The system configuration includes: flat-plate evacuated solar collectors, a double-stage LiBr-H2O absorption chiller, gas-fired auxiliary heater, a closed loop cooling tower, pumps, heat exchangers, storage tanks, valves, mixers and controllers. The novelty of this study lies in the utilization of flat-plate stationary solar collectors, manufactured by TVP Solar, rather than concentrating ones (typically adopted for driving double-stage absorption chillers). Such devices show ultra-high thermal efficiencies, even at very high (about 200°C) operating temperatures, thanks to the high vacuum insulation. Aim of the paper is to analyse the energy and economic feasibility of such novel technology, by including it in a prototypal solar heating and cooling system. For this purpose, the solar heating and cooling system design and performance were analysed by means of a purposely developed dynamic simulation model, implemented in TRNSYS. A suitable case study is also presented. Here, the simulated plant is conceived for the space heating and cooling and the domestic hot water production of a small building, whose energy needs are fulfilled through a real installation (settled also for experimental purposes) built up close to Naples (South Italy). Simulation results show that the investigated system is able to reach high thermal efficiencies and very good energy performance. Finally, the economic analysis shows results comparable to those achieved through similar renewable energy systems.

Solar heating and cooling systems can significantly contribute to the energy and climate European goals. A complete assessment of this contribution needs the analysis of these systems from a life-cycle perspective, in order to estimate the energy and environmental costs of their manufacturing and end-of-life, and to compare these costs with the benefits obtained during operation. A well-established methodology to fulfil this task is the Life Cycle Assessment (LCA). The paper describes some LCA experiences of solar heating and cooling systems, developed within the Task 53 “New generation solar cooling & heating systems (PV or solar thermally driven systems)” of the International Energy Agency. The results of these analyses can be useful to orientate manufacturers, researchers and decision makers for a more sustainable use of solar technologies.

A centralized solar hybrid heating and cooling system satisfying the thermal, cooling and sanitary water demands of a typical Italian small district composed of six residential buildings situated in Naples (southern Italy) is modelled, simulated and analysed through the software TRNSYS over a period of 5 years. The plant is based on the operation of solar thermal collectors coupled with seasonal borehole storage; the solar field is also composed of photovoltaic solar panels connected with electric energy storage. An adsorption chiller powered by solar energy is adopted for cooling purposes, while a condensing boiler is used as an auxiliary unit. The performance of the proposed system has been assessed from energy, environmental and economic points of view and contrasted with the operation of a typical Italian heating and cooling plant, highlighting the following main results: saving of primary energy consumption up to 40.2%; (decrease of equivalent CO2 emissions up to 38.4%; reduction of operating costs up to 40.1%; and simple pay-back period of about 20 years.

Solar heating and cooling (SHC) systems play an important role in the achievement of energy and climate European goals. The benefits of these technologies should be evaluated taking into account their lifecycle energy and environmental impacts, calculated by applying the Life Cycle Assessment (LCA) methodology. The development of a complete LCA can be difficult and time-consuming particularly for no-LCA experts, discouraging them in the inclusion of the lifecycle perspective in their assessments. To overcome this limit, the paper presents “ELISA - Environmental Lifecycle Impacts of Solar Air-conditioning systems”, a user-friendly simplified tool for estimating the lifecycle energy and environmental benefits/impacts of solar technologies in different geographic contexts compared to conventional plants. ELISA can be used by researchers, designers and decision-makers to introduce the lifecycle thinking approach in the design phase of SHC systems, taking into account environmentally sound considerations in the field of the solar systems.

A design was created to provide a novel passive control that operates a passive solar heating and cooling system for residential homes in Wyoming. Mathematical models were developed to determine the pertinent parameters of a control that will allow air to flow in or out of a house for heating or cooling purposes. The control was designed to be implemented in existing passive solar collector systems. It is composed of bimetallic spiral coils, ideally made of ASTM B388 TM2 ��� an alloy composed of 72% manganese, 18% copper, and 10% nickel for the high expansion component while the low expansion component is composed of 36% nickel and 64% iron, an aluminum shaft, and a damper made from ultra-high-molecular-weight (UHMW) plastic. The control has the ability to be adjusted by a user friendly dial similar to existing thermostat dials. The mathematical models for the control show a maximum deflection of 42 degrees of rotation relative to a coupled 160 degree temperature change within the collector and a 50 degree temperature change within the room that would allow for either heating or cooling. The control design provides an effective way to passively operate a passive solar heating and cooling system.

Using conventional fossil fuels causes both energy crisis and environmental pollution. Renewable energy with the merits of almost unlimited availability and environmental-friendliness provides a perfect solution to the problem. Solar energy is widely recognized as one of the most important renewable energy resources due to its even distribution, safety and serving as sources for others. In past decades, global solar thermal capacity increases rapidly and now it has been widely used worldwide to provide heating and cooling. To understand the current progress of relevant technologies and the future development, this paper briefly summarizes the current situation of solar heating and cooling, and then some new achievements in related areas and potential future market penetration are discussed. It is found that solar hot water heating system's development is in fast lane in recent years with evacuated tube solar collector dominating the mass market. How to integrate solar collecting system with different types of buildings is the main research and development direction for solar building heating system. Large-scale district water heating system and solar PVT system as the most promising solutions attract extensive attentions. For solar cooling, efforts have been made to improve the efficiency of conventional solar thermal cooling methods in terms of adsorption and absorption technology. In addition to technical development, economic analysis of solar heating and cooling system is also discussed. Return of investment period is widely adopted to evaluate the economic performance. Results reveal that low initial cost and advantageous allowance are the most efficient ways to make solar heating and cooling system economically attractive. This paper is presented and recommended by 5th International Conference on Nuclear and Renewable Energy Resources.

Solar heating and cooling systems for space heating and cooling are experiencing a growing trend and interest. However, the actual energy and environmental performance of small/medium size installations is not clearly foreseeable. In this paper, an analysis of such systems using adsorption chillers in different European climates is presented. Solar systems have been simulated in TRNSYS and compared to a conventional system employing a vapour compression unit. The results have been used for a Life Cycle Assessment (LCA) study, determining the potential impact during the whole life of the system, from raw materials supply to its end-of-life. The LCA has been carried out by using the LCA tool developed in the framework of the International Energy Agency SHC Task 48. Results showed that the useful life of the system is a key parameter: for a useful life of 10 years, the conventional system performs better than the renewable-based one for almost all the locations. However, if a longer life is achieved (15 or 20 years), solar systems show environmental advantage under almost all the climatic conditions: the environmental benefits of using a solar system during the operation step counterbalance the additional impact generated during the other life-cycle steps.

This chapter presents a detailed theoretical study, numerical modelling and some applications for solar heating and cooling systems focused on active and combisystems. Important information’s on simulating solar heating systems are discussed and the TRNSYS program is also briefly described. Additionally, a detailed review of different solar thermal-driven refrigeration and cooling systems including sorption technology (open systems or closed systems) and thermo-mechanical technology (ejector system) is also provided. The study refers to a comparison of various solar thermal cooling systems, and to some suggestions for the use of these systems. A comprehensive survey of solar thermo-electric (TE) cooling systems is also provided. Finally, the possibility of solar TE cooling technologies application in “nearly-zero” energy buildings is briefly discussed and some future research directions are included.

Assessing the performance of solar heating and cooling systems, especially cooling systems using solar thermal or photovoltaic driving energy, in a common comparable format, is complicated by the numerous, alternative energy sources and design possibilities. A generalized technical and economic assessment methodology was developed and tested in the course of IEA SHC Task 53. This paper is summarizing the key facts for the assessment and showing the evaluation on the basis of two simulated cases including sensitivity analysis of main boundary conditions. One case is comparing an air/water heat pump with photovoltaic and solar thermal support for a small multifamily house located in Madrid. The second case is comparing a solar thermal driven absorption chiller with a photovoltaic supported heat pump system for a hotel with dominant domestic hot water demand in Innsbruck. The sensitivity analysis shows that photovoltaic and solar thermal systems are cutting across with the same trends. Lower costs have to be derived first, followed by the efficiency of the system. Cost competitiveness is achievable for both technologies with appropriate system design and control strategies.

In this paper, a novel purposely designed dynamic simulation model for the performance analysis of solar heating and cooling systems is presented. The investigated system layouts are based on single stage LiBr–H2O absorption chillers and on both evacuated tube and concentrating photovoltaic thermal solar collectors. Furthermore, both electric chiller and gas fired heater backup system are considered. Such model is implemented in a computer code written in MATLAB. Here, the optimisation of several system design and operating parameters in terms of energy saving is also carried out. A code to code analysis is performed comparing the obtained simulation results vs. those achieved by a TRNSYS model available in literature. The simulation code for the concentrating photovoltaic thermal solar collectors is validated by experimental data. A good agreement among results is observed in both the cases. A suitable case study referred to a building including both offices and dwellings located in Northern and Southern Italy is presented. High primary energy savings are obtained for some of the investigated system layouts. By evacuated tube collectors solar field such savings can reach 74%, while shifting to concentrating photovoltaic thermal solar collectors they often surpass 100%. The system economic profitability strongly depends on future scale economies and eventual public funding.

In this paper, a parametric analysis of two solar heating and cooling systems, one using an absorption heat pump and the other one using an adsorption heat pump, was performed. The systems under investigation were designed to satisfy the energy requirements of a residential building for space heating/cooling purposes and domestic hot water production. The system with the absorption heat pump was analyzed upon varying (i) the solar collectors’ area, (ii) the volume of the hot water storage, (iii) the volume of the cold water tank, and (iv) the climatic conditions. The system with the adsorption heat pump was evaluated upon varying (i) the inlet temperature of hot water supplied to the adsorption heat pump, (ii) the volume of the hot water storage, (iii) the volume of the cold water tank, and (iv) the climatic conditions. The analyses were performed using the dynamic simulation software TRNSYS in terms of primary energy consumption, global carbon dioxide equivalent emissions, and operating costs. The performance of the solar heating and cooling systems was compared with those associated with a conventional system from energy, environmental and economic points of views in order to evaluate the potential benefits.

Life Cycle Assessment (LCA) is an effective methodology to assess the energy and environmental impacts of energy systems during their life cycle, including manufacturing, operation and end-of-life. The aim of the paper is the application of a simplified LCA tool, developed in the framework of the International Energy Agency Solar Heating and Cooling Task 48, for comparing different typologies of solar assisted heating and cooling systems. In detail, solar thermal heating and cooling systems located in Palermo (southern Italy) and in Zurich (Switzerland) were compared with conventional systems assisted by grid connected and stand-alone photovoltaic plants. A validation of the tool was also carried out by comparing the obtained results with those of in-depth LCA studies. The results showed that the best system configuration in Palermo is the conventional system assisted by a grid-connected photovoltaic plant. Its impact on global energy requirement is about 83.7% and 74.5% of the corresponding impact of the solar thermal heating and cooling and the conventional system assisted by a stand-alone photovoltaic system, respectively. Different considerations can be made for Zurich, where the solar heating and cooling system performs better than the others; it is characterized by a global energy requirement that is 85.3% and 81.2% of the grid-connected and stand-alone photovoltaic assisted conventional systems, respectively. A similar trend is traceable for the global warming potential indicator. The validation of the LCA tool proved it to be reliable since deviations with a detailed LCA of the same system are contained below a 5% difference in all the comparable systems.

Parametric optimization using dynamic simulation of a solar thermal system for producing hot water, space heating and cooling was developed. The system layouts include a single-effect absorption chiller activated by heat generated by flat plate solar collectors and stored in a solar storage tank. Two construction types were compared; the first is the typical construction in Algeria (low thermal mass with U-values of 1.25 W/m 2 K, single glazing), which represents the majority in the country, while the second is a High-Energy-Performance building (with U-values of 0.35 W/m 2 K, double glazing), representing the pilot project called ECO-BAT. Three of Algeria's regions were considered to evaluate the climatic effect of solar systems integration. Algiers represents the coastal region; Djelfa, the highlands region; Tamanrasset, the Sahara region. In parametric study, two solar collectors' field parameters were analysed, including the surface area and the tilt angle. The results indicated that building loads are significantly reduced (12%, 44% and 22% for Algiers, Djelfa and Tamanrasset, respectively). The solar energy contribution is more than 60% for all cases, a significant contribution for an efficient building. In all cases, we observed that the solar fraction reaches more than 45% when the optimum parameters of the solar system are selected.

A purposely developed dynamic simulation model for different Solar Heating and Cooling (SHC) systems including adsorption and absorption chillers driven by Evacuated Tube solar Collectors (ETC) and Concentrating PhotoVoltaic/Thermal (CPVT) collectors is presented. The modelled system layouts are capable to simultaneously produce electricity, space heating/cooling and domestic hot water. A case study focused on a representative cluster of two buildings, including office and residential spaces, located in cold and temperate European climate zones, is developed. A comprehensive parametric analysis is carried out in order to find out the design and operating conditions for the optimal energy performance of systems.

The application of solar heating and cooling systems for building air-conditioning actually shows a significant potential of exploitation, particularly in sunny regions. The choice whether or not to apply such technologies in different climates should be based on the assessment of their energy/environmental, economic and social sustainability, as well as their technical characteristics as reliability, durability and energy efficiency. To support researchers and decision-makers in the selection of the best solar air-conditioning solution in a specific geographic and energy context, the paper proposes a set of technical, economic, energy/environmental and social key performance indicators. The research activity was developed within the Task 53 “New generation solar cooling & heating systems (PV or solar thermally driven systems)” of the International Energy Agency.

Exploiting solar energy technology for both heating and cooling purposes has the potential of meeting an appreciable portion of the energy demand in buildings throughout the year. By developing an integrated, multi-purpose solar energy system, that can operate all twelve months of the year, a high utilisation factor can be achieved which translates to more economical systems. However, there are still some techno-economic barriers to the general commercialisation and market penetration of such technologies. These are associated with high system and installation costs, significant system complexity, and lack of knowledge of system implementation and expected performance. A sorption heat pump module that can be integrated directly into a solar thermal collector has thus been developed in order to tackle the aforementioned market barriers. This has been designed for the development of cost-effective pre-engineered solar energy system kits that can provide both heating and cooling. This thesis summarises the characterisation studies of the operation of individual sorption modules, sorption module integrated solar collectors and a full solar heating and cooling system employing sorption module integrated collectors. Key performance indicators for the individual sorption modules showed cooling delivery for 6 hours at an average power of 40 W and a temperature lift of 21°C. Upon integration of the sorption modules into a solar collector, measured solar radiation energy to cooling energy conversion efficiencies (solar cooling COP) were between 0.10 and 0.25 with average cooling powers between 90 and 200 W/m2 collector aperture area. Further investigations of the sorption module integrated collectors implementation in a full solar heating and cooling system yielded electrical cooling COP ranging from 1.7 to 12.6 with an average of 10.6 for the test period. Additionally, simulations were performed to determine system energy and cost saving potential for various system sizes over a full year of operation for a 140 m2 single-family dwelling located in Madrid, Spain. Simulations yielded an annual solar fraction of 42% and potential cost savings of €386 per annum for a solar heating and cooling installation employing 20m2 of sorption integrated collectors.

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.

A solar-heating-and-cooling (SHC) system, consisting of a flat-plate solar collector array, a hot water storage tank, and an absorption chiller unit is designed and modeled to satisfy thermal loads (space heating, domestic hot water, and space cooling). The system is applied for Nicosia, Cyprus, a location with prolonged summer-like conditions, where heating demand is moderate, while space cooling demand is comparatively very high. The study investigates the potential of a solar system installed and operated onsite in a detached single-family household to satisfy all necessary thermal loads. The hot water storage tank is also connected to an auxiliary heater (diesel-fired boiler) to supplement solar heating, when needed. The main purpose of the study is to model the overall system and contact a parametric study that will determine the optimum economic system performance in terms of design parameters. The system is compared, through a cost analysis, to an electric heat pump (EHP) system. It is found that the optimum system combination of solar collector area and volumetric capacity of the hot water storage tank is 70m2 and 2000L, respectively. The total annualized cost (in USD) for the optimum SHC system is $3,719. The sensitivity analysis showed that the SHC system would be unfavorable to compete with EHP technology, if the solar collector cost is above $360/m2. © 2015 Elsevier Ltd. 117 59 73 59-73

The building sector accounts for more than 40% of the global energy consumption. This consumption may be lowered by reducing building energy requirements and using renewable energy in building energy supply systems. Therefore, a nearly zero-energy building, incorporating a solar heating and cooling system, was designed and built in Beijing, China. The system included a 35.17 kW cooling (10-RT) absorption chiller, an evacuated tube solar collector with an aperture area of 320.6 m2, two hot-water storage tanks (with capacities of 10 m3 and 30 m3, respectively), two cold-water storage tanks (both with a capacity of 10 m3), and a 281 kW cooling tower. Heat pump systems were used as a backup. At a value of 25.2%, the obtained solar fraction associated with the cooling load was close to the design target of 30%. In addition, the daily solar collector efficiency and the chiller coefficient of performance (COP) varied from 0.327 to 0.507 and 0.49 to 0.70, respectively.

This paper presents a user-friendly Life Cycle Assessment tool, which aims to support researchers, designers and decision-makers in evaluating the life cycle energy and environmental advantages related to the use of solar heating and cooling (SHC) systems in substitution of conventional ones, considering specific climatic conditions and building loads. The tool was developed within the Task 48 “Quality Assurance & Support Measures for Solar Cooling Systems”, promoted by the International Energy Agency in the framework of the SHC Programme.

Conventional heating and cooling systems are responsible for large amounts of carbon dioxide release to the environment, as well as for the use of harmful refrigerants regarding the greenhouse effect and the ozone depletion potential. Solar radiation is a clean form of energy, which is required for almost all natural processes on earth. In South Africa, the majority of produced electricity is generated from fossil fuels and the potential of renewable energy sources is vast, solar radiation in particular is in abundance. The upper limit for Global Horizontal Irradiance (GHI) in South Africa can be as high as 2 300 kWh/m2/a, whereas the Direct Normal Irradiance (DNI) value attains a maximum of 2 900 kWh/m2/a, which is significantly higher than it is in other regions worldwide. The global air conditioning systems market has been estimated to reach 78.8 million units by 2015 due to increasing living standards, comfort expectations and global warming. South Africa is not the best performer regarding renewable energy use among African countries and there is a long way to go to achieve a sustainable environment. This paper seeks to investigate the feasibility and the sustainability of solar driven air conditioning system in South Africa based on meteological weather data. Currently, renewable energy is a topic of interest in South Africa after the 2008 energy emergency when power outages were rolled out due to inadequate maximum load planning. Solar air conditioning technology remains an untapped technology in South Africa.

This paper analyzes different control strategies for the thermal storage management in Solar Heating and Cooling systems (SHC) for different Italian climates. This novel thermal storage system consists in a variable volume storage tank system, which includes three separate tanks and a number of mixers and diverters. Such devices are managed through two different control strategies, based on combinations of series/parallel charging and discharging approaches. Thus, it is possible to vary the thermal storage capacity as a function of the combinations of solar radiation availability and user thermal/cooling energy demands. The system allows one to either increase or reduce the number of active tanks when the occurring mismatch between the solar energy supply and the user demand is either high or low, respectively. In addition, the surplus of solar energy is used through a heat exchanger included in the solar loop for the production of Domestic Hot Water (DHW). This novel variable-volume storage system, in all the proposed configurations, is also compared with a constant-volume storage system from the energetic and economic points of view. In addition, in order to determine the set of the synthesis/design variables which maximize the system profitability, a parametric analysis is implemented. A case study developed for an office building located in different Italian climatic areas is also presented. Simulation results show that the analyzed SHC systems system configurations may be profitable for all those cases and weather locations in which a sufficiently high solar fraction is achieved.

YÖK Tez No: 579909 Mevcut tez çalışmasında Antalya bölgesinde bulunan bir villanın yıllık ısıtma ve soğutma yükleri, güneş enerjisi destekli absorbsiyonlu sistemle karşılanarak uygulamanın ekonomik analizinin yapılması amaçlandı. Isıtma ve soğutma sistemleri tasarlanırken ilgili standartlara ve yönetmeliklere bağlı kalındı. Binanın yıllık ısı kaybı ve ısı kazançları belirlenerek cihaz seçimleri yapıldı. Kurulan sistemin geleneksel sistemlere göre yatırım maliyeti hesaplanarak düşük faizli kredilendirme sistemiyle yaşam döngüsü araştırıldı. Binanın yalıtım hesapları, TS825 "Binalarda Isı Yalıtım Kuralları" Standardına uygun olarak yapıldı. Binanın ısı kaybı ve ısı kazançları FineHVAC programıyla hesaplandı. Isı kaybı hesabında Avrupa'da zorunlu hale gelen EN12831 hesap metodu, ısı kazancı hesabı içinse CLTD metodu kullanıldı. Güneş kollektör alan tayini ve güneş faydalanma oranı için Ø-f chart metodu uygulanırken, termoekenomik analiz içinse P1,P2 metodu kullanıldı. Yatırım maliyeti hesaplarında ürün ve işçilik tedariği için detaylı pazar araştırması yapıldı. AutoCAD çizim programıyla mekanik sistemler projelendirilerek bulunan sonuçlar için özet tablolar hazırlandı. Uygulanan metod hesaplamaları sonucunda binanın ısı kaybı 20,5 kW, ısı kazancı 40,3 kW olarak bulundu. Yapılan hesaplar 125 m2 güneş kolektörü sistemine ilave 40 kW güneş destekli absorbsiyonlu soğutucu kullanılmasının toplam faydalanmada %36 oranının yakalandığını gösterdi. Yapılan ekonomik analiz hesapları sonucunda güneş absorbsiyonlu sistemin kurulumu için yaklaşık 394.000,00 TL değerindeki yatırım maliyetinin kredilendirme sistemiyle 16. yılda pozitife geçtiği görüldü. In this thesis, the annual heating and cooling loads of a building located in Antalya region were met with solar assisted absorption chiller system and the economic analysis of the application was investigated. During the study, design of heating and cooling systems adhered to related standards and regulations. Heating and cooling loads were all calculated and the necessary equipment were selected. The investment cost of the installed system was calculated in comparison to the conventional systems and the life cycle save analysis of the system was investigated with a low-interest credit system. The insulation requirements of the building was done acoording to TS standards called Heat Insulation Rules in Buildings. The heat loss and gains of the building were calculated using the FineHVAC Program. In the study, EN12831 method, compulsory in Europe, for the calculation of heat loss and CLTD method for the calculation of heat gain have been utilized. Moreover, the Ø-f chart" method and P1,P2 method were used for collector area-solar fraction calculations and thermoeconomic analysis, respectively. Detailed market research was conducted for the supply of products and labor in the investment cost accounts. Mechanical systems are designed with AutoCAD drawing program and summary tables were prepared according to findings. In the light of materials and methods, the heating load of the building was calculated as 20.5 kW and the cooling load was calculated as 40.3 kW. The calculations showed that 36% of the total utilization was achieved by using a 40 kW solar absorption chiller assisted with 125 m2 solar collectors. As a result of the economic analysis, it was seen that the investment cost amounting to 394.000,00 TL has been positive for the 16th year through the credit system.

© Published under licence by IOP Publishing Ltd. A composite phase change material (CPCM) of myristic acid/palmitic acid/sodium myristate (MA/PA/SM) and of myristic acid/palmitic acid/sodium laurate (MA/PA/SL) were impregnated with purified damar gum as called Shorea Javanica (SJ) to improve the thermal conductivity of CPCM. The thermal properties, thermal conductivity, and thermal stability of both CPCM have investigated by using a Differential Scanning Calorimetry (DSC) thermal analysis, hot disc thermal conductivity analyzer, and Simultaneous Thermal Analyzer (STA), simultaneously. However, a chemical compatibility between both fatty acid eutectic mixtures and SJ in composite mixtures measured by Fourier Transform Infra-Red (FT-IR) spectrophotometer. The results were obtained that the thermal conductivity of MA/PA/SM/SJ and MA/PA/SL/SJ eutectic composite phase change material (CPCM) were improved by addition 3 wt.% and 2 wt.% of Shorea javanica (SJ), respectively, without occur a significant change on thermal properties of CPCM. Moreover, the absorbance spectrum of FT-IR shows the good compatibility of SJ with both MA/PA/SM and MA/PA/SL eutectic mixtures, the composite PCM also present good thermal performance and good thermal stability. Therefore, it can be noted that the purified Shorea Javanica proposed, the as high conductive material in this study was able to improve the thermal conductivity of eutectic PCM without any significant reduction on its thermo-physical and chemical properties and can be recommended as novelty composite phase change material for thermal energy storage application.

With the increasing concerns on energy conservation and environmental protection, solar heating and cooling (SHC) system represents an attractive candidate in building sector. In this paper, an integrated SHC system driven by parabolic trough collector (PTC) and double-effect H2O/LiBr absorption chiller was presented. The energy generated by solar collectors was supplied to the absorption chiller during the cooling period, and was directly used for space heating with the integration of plate heat exchanger during the heating period. The mathematical models of the whole system including the collector, the double-effect absorption chiller and the plate heat exchanger were established and were validated by field tests. Based on the proposed models, comparison of the SHC system and the conventional gas-driven absorption heating and cooling system was carried out by case study. The annual performances as well as energetic, economic and environmental assessments of the proposed system were investigated. Results show that, 21.3% of the primary energy consumption and 18.8% of the CO2 emission can be reduced in SHC system. Therefore, the proposed integrated solar heating and cooling system has a promising application prospect in sustainable development in view of its considerable energy saving benefits, potential economic viability and environmental friendly characteristics.

This paper presents thedevelopment of a compact and cheap solar heating system based on photovoltaic panels, heat pump and heating storage through a smart regulation from a technical and economical point of view. The heat pump can be standard and have its own regulation. The building's owner may interact with the regulation through a web service to visualize the monitoring of the installation, update the calendar of the presence and change the operation mode. One of the goals of the regulation is to optimize the consumption of his own electricity production and therefore minimize the electricity taken from the grid. Several means are developed to reach the main objective. On one hand, the regulation takes into account the weather forecast to anticipate the future heating's needs and the photovoltaic production. Weather forecast data allows also to optimize the storage in hot water tanks and in the building structure. On the other hand, the project includes the development of an electronic module which collects the monitoring data and gives the commands to the heat pump and the pumps. This is accomplished without any intrusion in the heat pump's own regulation and therefore the user keeps the constructor's warranty. The new regulation was validated numerically. The expected energy gain due to the weather forecast is about 10%, while the one due to the self-consumption and the heat storage management will bring another 10-15%.

The solar heating and nocturnal radiant cooling techniques are combined aiming at a novel solar heating and cooling panel (termed as SHCP) to be easily assembled as construction components for building roofing or envelope and also compatible with surroundings for its versatile coating colors, which can remove the double-skin mode from conventional solar equipment. SHCP has two functions for heating and cooling collecting. In this paper, the heating and cooling performances were analyzed in detail based on a small scale experimental system and effects of air gap and coatings were investigated. The results show that in sunny day of extreme cold January in Tianjin, China, the daily average heat-collecting efficiency is 39% with the maximum of 65%, while in sunny night during hot seasons the average cooling capacity can reach 87 W/m2. When two different coatings were sprayed on SHCP without air gap, its heating and cooling performances were all analyzed, the daily average heat-collecting efficiency was 39% and 27% with the maximum points of 65% and 49%, respectively, and the cooling capacity was almost the same of 30 W/m2 in January.

A residential solar-heating-and-cooling (SHC) system is a possible alternative for the reduction of fossil fuel consumption to cover residential energy loads. These systems can cover all thermal loads, i.e. space heating, space cooling and domestic hot water preparation. Space cooling is fulfilled through a heat-activated (hot water), single-effect LiBr-water absorption chiller. Proper operation of such a system requires coupling of the solar collector array to a hot water storage tank with auxiliary heating. Auxiliary heating, in this case in the form of a diesel-fired boiler, is necessary to supplement heating in the storage tank when demand exceeds solar heating availability. In this study emphasis is given on the effect of the collector tilt angle (slope) on the performance of a SHC system. A constant slope throughout the year simplifies system configuration and maintenance, but on the other hand a variable slope improves performance, in terms of energy efficiency, and thereby lowers the operating cost of auxiliary heating. The results of the study show that it is economically beneficial to vary the slope throughout the year (on a monthly basis), since $233/year can be saved when a variable slope is used.

One of the necessary steps to push solar cooling into the market is to define a suitable energy label. The bases for such a label are appropriate testing and rating procedures to which a labelling directive can refer to. Thus a valid and accepted standard for the measurement procedure and performance calculation of solar cooling systems is required. Many different rating methods are available in the field of solar heating and cooling. These comprise different methodical characteristics such as component testing and whole system testing, with the equipment under test measured under steady-state or dynamic conditions, measured in a laboratory, entirely indoor partly outdoor. The output of the measurement is some kind of description of the equipment under test such as performance points or parameters of a model that have been fitted and identified with the measurement data. Based on this input, several approaches for the performance calculation can be observed such as direct extrapolation, look-up tables, frequency distributions or full dynamic simulations. The aim of this paper is to develop a common language for the characteristics applied among the different rating methods in order to help people get acquainted more easily. Firstly general requirements for test and rating methods are brought up. Secondly a classification is proposed which comprises the main characteristics of testing and rating methods as well as options for each of these characteristics. Finally, the classification is applied on the most common European methods for solar heating and cooling systems.

In the following report the design of the dry cooler unit for the ZEOSOL system will be shown. It was carried out on the basis of experimental data of the sorption chiller produced by the partner FAHREN. The design process took into account the dynamics of sorption chiller in order to determine the most difficult operating conditions. A simple basic commercial software was employed for the design process and the calculation of main HEX parameters and selection from a supplier catalogue. The designed unit is a dry heat rejection device with high efficiency at very high temperatures. It was designed for Southern Europe climate (39.6 °C is the design ambient air temperature). Detailed drawings are also enclosed. A description of the back-up heat pump and it`s design is given at the end of the report.

This paper presents the dynamic modelling of a hybrid cascade chiller for solar cooling in industrial applications driven by Fresnel solar thermal collectors. The chillercomprises an adsorption module, which is directly connected to the bottoming vapor compression chiller. This cascade configuration allows enhancing theoverallelectric COP, since the adsorption module is operated to dissipate the heat rejected by the vaporcompression chiller, thus reducing the condensation temperature quite below the ambient temperature. The model was implemented in Dymola/Modelica, allowing describingheat and mass transfer phenomena insideeach component. The complete model was then validated against experimental data obtained on a cascade chiller prototype at the CNR ITAE lab. Finally, a reference daily simulation was performed to evaluate the ability of the developed chiller in providing cooling energy to a typical industrial application.

Aim of the present deliverable is to report on the system modelling analysis that was carried out within WP4, T4.1 of the project, whose goal is the development of a system model. The objective of the model is twofold: optimal sizing of system components and definition of the control strategy to be applied in the demo-site installation and for the correct operation of the system. In order to achieve such goals, leading principle was the realization of a simplified sizing tools, that allows for an easy selection of the components and can be scalable and adaptable to different conditions, in terms of place of installation and thermal power output required.

The aim of this document is to assess the performance of the ZeoSol system with focus on different locations. From these investigations it can be shown whether the simplified design tool developed within ZEOSOL leads to a system layout that shows the performance expected. From the comparison of the performance in different climatic conditions necessary modfications of the system design can be deduced.

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 the following report the testing activity carried out on the electric chiller unit for the ZEOSOL system is shown. It was carried out on the chiller unit realized by the partner FAHREN and shipped to our labs in the second week of June. The testing process took into account the real operating conditions of a Mediterranean climate (Athens is the selected demo site). An internal testing protocol, agreed with the partner FAHREN, has been employed for the testing process and the calculation of main Key Performance Indicators (KPIs) have been done accordingly with formulas showed in the report. The performance of the electric chiller and its behavior at different and extreme outside temperature has been measured.

The heating and cooling systems of apartment buildings based on combined solar heat-pump equipment has been considered and the procedure of calculating its parameters has been worked out. A technical-economic analysis has been performed and compared with the boiler-setting version.

The solar heating and cooling system simulation platform has been established based on Trnsys in this paper. Taken the villa building in cold areas of China as research objects, the solar heating and cooling system with different solar energy resources division have been analyzed. System optimization designs have been proposed and the optimum storage tank volume and solar fraction of the solar heating and cooling system have been given. The results show that the solar irradiation is one of the most influence factors in solar heating and cooling system for storage tank volume and solar fraction. The higher solar irradiation can be acquired, the larger volume of storage tank and solar fraction.