Solar Assisted Heating System Research Articles

Performance prediction and analysis of a solar assisted medium-deep geothermal heating system

Abstract The solar assisted medium-deep geothermal heating (SAMGH) system is a novel kind of heating system that can combine the benefits of geothermal and solar energy. However, the variations in borehole heat exchanger (BHE) performance and the intermittency of solar energy pose challenges for predicting the overall performance of the coupled system and designing the operational strategies. To conduct simulation on the SAMGH system for performance prediction and analysis, a coaxial medium-deep borehole heat exchanger coupled with the solar energy heating system for an office building in Xi’an was developed. The TRNSYS software was employed to establish the model of the coupled system. A ground source heat pump (GSHP) heating system was used for comparison. The simulation results showed that with the introduction of the solar energy and heat storage modules, the annual operating time of the geothermal system only accounts for 32.06%. The energy consumption of the coupled system can be reduced from 63585 kW to 44586 kW, and the energy consumption proportion of the geothermal system in total value decreased from 69.10% to 40.58%. Therefore, the average coefficient of performance (COP) of the heat pump and the system were improved by 63.71% and 91.77%, respectively. Moreover, because the solar energy is beneficial to the ground heat recovery, the average ground temperature increased from 42.5 °C to 43.88 °C after ten years of operation. The proposed design method and simulation results can serve as a reference for design method and performance analysis of the geothermal and solar coupled system.

Optimization of solar-air source heat pump heating system with phase change heat storage

The optimization of heating system has always been of much concern, among which the annual life cycle cost (ALCC) was widely used as an optimization method, while the non-guaranteed hours were often overlooked. This study proposed the elasticity-economy (E-E) objective function as an optimizing indicator, and demonstrated it taking a solar assisted heat pump heating system with phase change material (SC-ASHP-PCM) as an example. Firstly, the single variation impact was analyzed. After optimizing the thermal performance of sub-systems, the proportion of heat supplied by solar collector (SC) and phase change material (PCM) sub-systems increased by 5.4 % and 3.4 %, respectively. Subsequently, the Hooke-Jeeves algorithm was developed to optimize multi-factors, hence minimizing the E-E objective function. The optimal solution was achieved when the non-guaranteed rate was 5 % and the penalty factor was 150 CNY/h. Compared with the baseline situation, the system energy consumption (156.8 × 103 kW‧h) was reduced by 30 %, and the E-E objective function was reduced by 24 %. Furthermore, the minimum operating cost was 18.3 CNY/m2, saving up to 46 % compared to traditional heating systems. The method is generalized to obtain the optimal energy saving potential under different non-guaranteed hours, which provides guidance for the heating systems' design and operation.

Energy performance analysis of solar assisted gas-fired boiler heating system for floating roof oil tank

An innovative solar assisted gas-fired boiler heating system for floating roof oil tank is proposed to achieve the low carbonization of the conventional crude oil heating method. However, the dynamic energy transport performance of the proposed heating system affected by the key engineering parameters (crude oil capacity load, mass flow rate of heat transfer fluid (HTF), crude oil initial temperature) is unclear, which hinders the engineering application of this technology. In this regard, a simulation platform for solar assisted gas-fired boiler heating system for floating roof oil tank is established, and the above mentioned engineering parameters are investigated. The results show that under the condition of combined heating of evacuated tube solar collector (ETSC), phase change heat storage tank (PCHT), and auxiliary heat source (AHS), the system can achieve stable operation by means of controllers. With the increase of crude oil capacity load, the time for the crude oil to reach its design temperature is delayed, and up to 84.21% time lag is recorded. Apart from the contribution of AHS, the maximum annual heat supply of 43.37% is provided by PCHT and ETSC, presenting good energy-saving potential. Increasing HTF mass flow rate and crude oil initial temperature is a good strategy to reduce the output of AHS, in which the annual heat supply proportion of AHS decreases by 2.25% and 2.05%, respectively. The operating stability of proposed system is enhanced under the condition of higher HTF mass flow rate, compared to the 3.5 kg/s HTF mass flow rate, the safe reserve time increases by 31.44% for 7 kg/s and 34.24% for 14 kg/s HTF mass flow rate, respectively.

A comprehensive comparison study on household solar-assisted heating system performance in the hot summer and cold winter zone in China

Distributed solar heating systems have high energy-saving potential as clean and energy-efficient production units in residential building applications. Solar energy resources are weak in hot summer and cold winter zone in China, which makes it difficult to completely rely on solar energy to heat residential buildings. A critical challenge is the lack of a theoretical basis for how to choose the solar-assisted heating system form. In this paper, seven solar-assisted heating systems are modeled and their performances are evaluated in six cities by using TRNSYS software. In terms of performance indicators, the solar fraction, the season performance factor, and the heat efficiency are used to thoroughly discuss the viability of using solar heating technologies in this zone. Based on the results, the average indoor air temperature was maintained between 16 °C and 20 °C, and the lowest solar fraction obtained was 10.1%. The carbon emission reduction in each city ranged from 60 kg to 400 kg, yielding good environmental benefits. According to the comprehensive comparison of the six evaluation indexes considered, the parallel or dual-source solar-assisted air source heat pump system can be used in a zone with medium solar energy resources. It is more suitable to use a dual-source solar-assisted air-source heat pump system in a zone with poor solar energy resources. The findings of this work can guide and promote the widespread application of distributed solar heating in household residential buildings in the hot summer and cold winter zone in China.

Investigation of the effect of slurry mixing ratio and temperature on biogas production from cattle dung in a field-scale anaerobic digestion plant

The substrate/water ratio and temperature effects on biogas production rate were investigated using cattle dung as substrate. Initially, laboratory-scale experiments were performed considering three substrate/water ratios of 1:1.5, 1:1 and 1.5:1 in both controlled (35°C) and uncontrolled environments for 55 days. The substrate/water ratio of 1:1 achieved the highest specific cumulative biogas yield of 247.75 ml/gVS and 311.14 ml/gVS for uncontrolled and controlled digesters, respectively, and consequently, considered for field-scale experiments that were performed in 1 m3 capacity anaerobic digestion plant at three different phases. An average volume of 6.26 m3/week of biogas was generated during the summer season (first phase) against the loading of 50.00 ± 1.50 kg cattle dung slurry/day. Subsequently, in the third phase of the experiment, the integration of the solar-assisted heating system improved the cumulative biogas yield by an average of 9.93% over the digester without solar-assisted heating (second phase) during the winter season. The correlation coefficient (R2 ) value was also found to be approximately 0.99, revealing that predicted results perfectly fit experimental values. The present study confirms that adopting a passive solar-assisted heating system for a field-scale anaerobic digestion plant is a novel approach towards enhancing the biogas yield.

Modelling of solar assisted district heating system with seasonal storage tank by two mathematical methods and with two climatic data as input

The goal of the study is to present two independent solutions capable of modelling the thermal behaviour of the solar assisted district heating systems with seasonal thermal storage. The study uses a new approach in modelling the thermal behaviour of the solar assisted district heating systems, by using two calculation methods: the analytical method and TRNSYS to perform the simulations, and by using two climatic data as input: EnergyPlus and Meteonorm. The heat demand of the buildings, the shares of energy produced by the solar thermal system, and by the gas boiler used as backup, and a very large number of the system parameters: temperature variation in each layer of the seasonal heat storage tank, temperatures, and flow rates on all the circuits, etc. were calculated. The results were compared using three parameters: Mean Deviation, Mean Bias Error and Root Mean Square Error. All the results calculated with the two methods were found to be very close. The annual solar fraction was found to be in the range of (34.9–50.2) %, depending on the type of the considered solar thermal collector, the combination of calculation method and climatic data as input. The study proves that both analytical method and TRNSYS can be used successfully to simulate the thermal behaviour of solar assisted district heating systems with seasonal heat storage.

Performance analysis and multi-objective optimization of solar assisted ground-source heat pump heating system

ABSTRACT Heating through a solar assisted ground-source heat pump system is an efficient method, and optimizing its parameters can significantly improve its energy efficiency. However, the research on the impact of the start-stop temperature difference of the heat collection cycle on the system is currently limited. To address this issue, this study aims to develop a SAGSHP system model located in Tianjin using TRNSYS software, investigate the effect of parameters such as the start-stop temperature difference on the system performance, and guide the optimization process. The optimization parameters include the collector’s area, the water tank’s volume, and temperature difference during the heat collection cycle. The NSGA-II algorithm is applied to perform multi-objective optimization to enhance the system’s energy efficiency and economy. Furthermore, a sensitivity analysis is conducted to study each variable’s impact on the optimization results. The variation in temperature between the start and stop of the collection cycle has a significant impact on the system’s performance, as revealed by the study. The optimal operation scheme lies within the boundary range of parameter settings. The optimization leads to a decrease of 8.63% in the system’s annual operating cost and a reduction of 1555 kWh in the annual power consumption. The relationship between the area of the collector and the temperature difference during heat collection startup is expressed as 0.034°C/m2, and the ratio to the tank volume is 1.33°C/m3. The degree of influence of optimization parameters on optimization results is ranked as V i>A i>T s>T e.

Performance analysis of a novel solar assisted ground source heat pump water heating system with graded thermal energy storage

The solar assisted ground source heat pump system (SAGSHP) is recognized as an efficient, clean and economical renewable energy technology for hot water supply. However, in SAGSHP systems with an all-day hot water supply, the solar collectors can only heat the water tank with intense solar radiation, which wastes moderate and weak solar resources. In addition, as the SAGSHP system draws heat from the soil for a long time, the soil temperature around the borehole decreases, causing the performance of the GSHP to deteriorate. To solve the above problems, a SAGSHP system with graded thermal energy storage (SAGSHP-GTES) was proposed. This paper investigated the performance and feasibility of the SAGSHP-GTES system, using a case study of hot water supply in a campus dormitory in Changsha, China. Firstly, the drawbacks of solar energy utilization in the conventional SAGSHP system were analyzed. Then, the SAGSHP-GTES system was modeled by TRNSYS, and its operational performance was evaluated and compared with the conventional SAGSHP system. Finally, the feasibility and performance of the SAGSHP-GTES system in different climate zones of China were analyzed. The results showed that the conventional SAGSHP system had a poor solar energy utilization efficiency, with an average thermal efficiency of the SC (ηSC) of only around 19.4%. The long period of operation caused the soil temperature to drop from 18.1 °C to 2.78 °C, which led to a decrease in system efficiency and an increase in electricity consumption. By controlling the heat collection of the SC and the graded utilization of solar energy in the SAGSHP-GTES system, a high ηSC of around 42.7% was obtained, which improved the system efficiency while eliminating the problem of soil temperature drop. After 15 years of operation, the soil temperature increased from 18.1 °C to 19.9 °C, which led to an increase in the coefficient of performance of the system (COPsys) from 3.77 kW/kW to 3.84 kW/kW and COPGSHP from 3.45 kW/kW to 3.5 kW/kW, and a reduction in electricity consumption from 51,746 kWh to 50,735 kWh. In addition, the conventional SAGSHP system was not feasible in severe cold zones (Harbin) and cold zones (Beijing) of China, where soil temperatures fell below 0 °C and freezing of the circulating fluid occurred, while the SAGSHP-GTES system showed excellent performance in all climatic zones of China and is a feasible and efficient technology for hot water supply.

Optimizing solar-assisted industrial heating and cooling system for cost-effective installation

Integrating solar thermal collectors into industrial processes could be a viable way to replace the use of conventional fuels and achieve economic and environmental goals. However, there is a need to consider the detailed dynamic operation of a system with storage on a systematic control scale to fully optimize realistic system performance under variable conditions by minimizing excess energy production and maximizing annual life-cycle cost savings. In this study, we developed a TRNSYS-based dynamic statistical optimization model and evaluated FPC-based solar-assisted heating systems to develop a cost-effective system design for two industries: MOHA soft drinks and Sheba leather factories in the Tigray region, Ethiopia. Three operating loads were compared: process heat, utility heat, and utility heat and chilled water. The optimized designs resulted in significant annual life-cycle cost savings, high solar fractions, and a good margin on temperature trends where solar collector size has a greater impact. Annual cost savings per unit area of solar collector for process and utility heat were in the range of $51–90/m2 for a collector mass flow rate and storage volume of 0.01–0.02 m3/h-m2 and 0.04–0.08 m3/m2, respectively. For the utility heat and chilled water loads, the values were $49/m2 for a mass flow rate of 0.04 m3/h-m2 and a storage volume of 0.07 m3/m2. Thus, the study supports the transient analysis of solar-assisted industrial heat. The case studies have shown that the method provides optimal solutions for the use of solar thermal energy. As investment and financial sourcing remain a priority challenge, the model and case study results could help in decision-making for similar and other production capacities, regions, industries, and solar technologies.

Güneş enerjisi destekli ısıtma sistemlerinde güneş kolektörü ve sıcak su deposu kapasitesi seçimi için parametrik analiz

In this study, a study was carried out on integrating solar assisted systems into heating systems in a building. For the study, an existing building was modeled with the DesignBuilder building energy simulation program. The scenarios were created on the model to determine the number of solar collectors and the capacity of the water tank used in solar assisted heating systems. The primary energy consumption, global costs and payback periods of the scenarios created were obtained by parametric analysis. According to the results obtained, the solution that reduces primary energy consumption the most is SYS20, the solution that reduces the global cost the most is SYS1 and the optimum solution is SYS7. Considering the payback periods, SYS1 was determined as the most appropriate solution to be applied in the study since it was the solution with the minimum payback period. At the end of the study, it was seen that primary energy savings could be reduced by up to 47% with solar energy assisted heating system. Thanks to the study, a reference source for the number of solar collectors and water tank capacity selection in Isparta and provinces with similar climates has been created.

Investigation of solar assisted air source heat pump heating system integrating compound parabolic concentrator-capillary tube solar collectors

Solar assisted air source heat pump heating systems are capable of achieving green heating where solar availability essentially affects its operation performance and application potentials, especially in higher-latitude regions, such as UK. Compound parabolic concentrator solar collectors can achieve high collector efficiency at high hot water temperature, benefitting to improve solar collection and corresponding thermal energy storage capacities. Though compound parabolic concentrator solar collectors have been widely investigated, application of such collector for solar assisted air source heat pump system is not studied yet. The paper reports numerical simulations of solar assisted air source heat pump heating systems that integrate compound parabolic concentrator-capillary tube solar collectors for domestic heating in the UK. The results show that, for the same seasonal performance factor, the size of the concentrated solar collector required is 12 m2 whereas the size of the flat plate solar collector required is 18 m2. This suggests one third reduction in the size of solar collector, significant reduction in cost and convenience for installation. The results also show the potential to further reduce the size of the concentrated solar collector to 9 m2 or less. The high collector efficiency of the compound parabolic concentrator-capillary tube solar collector enables much small size of solar collector, significantly lower cost and convenient for installation and wide rollout of solar assisted air source heat pump heating system to locations where solar irradiance is relatively lower.

Accuracy of key performance indicators in solar-assisted heating systems due to measurement uncertainties

In this paper, the influence of measurement uncertainties on the key performance indicators fsav and FSC in solar-assisted heating systems is investigated. The impact of temperature, volumetric flow rate, and irradiance sensors with different measurement accuracies is analysed with a combination of Gaussian error propagation and Monte Carlo Analysis. To identify the sensor equipment with best cost–benefit-ratio (BCBR), different sensor combinations are investigated. If fsav and FSC are to be measured, additional sensors must be installed. The resulting costs range from 250€ for an inexpensive equipment to 330€ for recommended BCBR equipment and up to 780€ for the maximum accuracy equipment. For smaller economically dimensioned systems the use of inexpensive sensors results in large uncertainties, e.g. fˆsav=(15.2±13.7)%. The uncertainties for larger systems are significantly lower, e.g. fˆsav=(56.7±6.3)%. This is true as well if better sensors are used. Regardless of the system’s size, with the BCBR sensor equipment the resulting expanded uncertainties can be reduced by 60% (relative) compared to the results with the inexpensive sensor equipment. With maximum accuracy sensor equipment the resulting expanded uncertainties can even be reduced by 77% (relative). The results show the importance of a carefully selected sensor equipment and the influence of the system’s size. Inexpensive sensors can lead to large uncertainty ranges for the important key performance indicators fsav and FSC. Thus, these key figures effectively cannot be used for assessing the performance of a solar-assisted heating system.

Performance enhancement and life cycle analysis of a novel solar HVAC system using underground water and energy recovery technique

• A novel solar-assisted HVAC in UAE was studied. • Energy recovery and passive techniques were investigated. • 31.5% space-cooling load was reduced by passive methods. • A good agreement was obtained between the analytical model and the experimental results. • A maximum COP of 5 was achieved compared to 3.82 in conventional system. This study focuses on the performance analysis of a novel solar-assisted heating, ventilation, and air conditioning (HVAC) system, using R407c as a refrigerant under United Arab Emirates (UAE) climate conditions. The energy recovery techniques and explicit passive techniques were investigated for reduction of energy consumption and overall cost by using underground water. It was found that the space-cooling load was reduced by 38.4% with the help of distinct passive methods. The underground average water temperature is stable at 28°C in the UAE throughout the year and thus, was used to decrease the cooling consumption. A reduction in cooling consumption and of compressor capacity of about 13% and 10%, respectively was achieved using these approaches. Good agreement was obtained between the analytical model and the experimental results. A comparison was also carried out between the proposed new system and the conventional system. Results indicated that the maximum COP of 5 was achieved with the proposed system, while COP in conventional system obtained 3.82. Furthermore, Eco Audit CES Edu pack software was used to analyses life cycle assessment to determine the new design’s variability. Overall, the proposed new system appears to be environmentally friendly, while economically viable.

Techno-economic assessment of solar assisted precinct level heating systems with seasonal heat storage for Australian cities

District or precinct level heating systems are a promising way to incorporate solar for decarbonising the building heating sector. Despite growing interest in these technologies in Europe and China, there are no large-scale district heating systems in Australia. This study shows that a combined solar heat driven Domestic Hot Water (DHW) and Space Heating (SH) system with seasonal storage is technically and economically feasible for major Australian cities. A precinct scale solar-assisted domestic hot water and space heating system with seasonal heat storage has been designed and evaluated for Australian conditions. Technical performance was evaluated using solar fraction, storage efficiency and heat collection efficiency parameters. Economic performance was evaluated using the Levelized Cost of Heat for solar thermal (LCOHst) and whole system Levelized Cost of Heat (LCOH) with a combination of component cost data from China and Europe and energy cost data from Australia. A parametric study to identify optimal collector area and storage volume sizes shows that the proposed system could achieve technical and economic targets in all five Australian cities considered. The lowest LCOHst is 0.0597 USD/kWh in Hobart. Sydney and Perth could use nearly 100% solar energy to cover the heating demand with the proposed design.

Heat distribution concepts for small solar district heating systems – Techno-economic study for low line heat densities

• Two novel distribution concepts are compared to conventional district heating. • A novel distribution system with central domestic hot-water heating is presented. • Hybrid distribution outperforms a conventional steel pipe system. • A complete low-temperature system outperforms hybrid distribution. • Reduction in line heat density favours a low-temperature GRUDIS system. The high operating temperatures in today’s district heating networks combined with the low energy demand of new buildings lead to high relative network heat losses. New networks featuring lower operating temperatures have reduced relative heat losses while enabling an increase in the use of solar heat. The primary aim of this study was to determine if a particular district heating system can be made more effective with respect to heat losses and useful solar energy, by considering different distribution concepts and load densities. A small solar assisted district heating system with a novel hybrid distribution system has been modelled based on a real case study. This model serves as a basis for two other models where the distribution system and heating network operating temperature is changed. A secondary aim of the study was to determine the economic implications of making these changes, by using costs estimates to calculate the contribution of essential system components to total system cost. Results indicate that a novel distribution concept with lower network temperatures and central domestic hot water preparation is most energy efficient in a sparse network with a heat density of 0.2 MWh/m∙a and a performance ratio of 66%, while a conventional district heating system performs worst and has a performance ratio of less than 58% at the same heat density. In an extremely sparse network with heat density of 0.05 MWh/m∙a, the performance ratio is 41% and 30% for these systems, respectively. A simple economic analysis indicates that the novel distribution concept is also best from an economic point of view, reducing the initial investment cost by 1/3 compared to the conventional concept, which is the most costly. However, more detailed calculations are needed to conclude on this.

Economic Analysis of Heat Distribution Concepts for a Small Solar District Heating System

One challenge in today’s district heating systems is the relatively high distribution heat loss. Lowering distribution temperatures is one way to reduce operational costs resulting from high heat losses, while changing the distribution system from steel pipes to plastic pipes and changing the heat distribution concept can reduce investment costs. The result is that the overall life cycle cost of the district heating system is reduced, leading to the improved cost competitiveness of district heating versus individual heating options. The main aim of this study was to determine the most cost-efficient distribution system for a theoretical solar district heating system, by comparing the marginal life cycle cost of two different distribution systems. A secondary aim was to determine the influence of the employed pipe type and insulation level on the marginal life cycle cost by comparing detailed economic calculations, including differences in pipe installation costs and construction costs, among others. A small solar-assisted district heating system has been modeled in TRNSYS based on a real system, and this “hybrid” model is used as a basis for a second model where a novel distribution system is employed and the heating network operating temperature is changed. Results indicate that a novel distribution concept with lower network temperatures and central domestic hot water preparation is most efficient both from an energy and cost perspective. The total life cycle costs vary less than 2% for a given distribution concept when using different pipe types and insulation classes, indicating that the investment costs are more significant than operational costs in reducing life cycle costs. The largest difference in life cycle cost is observed by changing the distribution concept, the novel concept having approximately 24% lower marginal life cycle cost than the “hybrid” system.

A waste to energy technology for Enrichment of biomethane generation: A review on operating parameters, types of biodigesters, solar assisted heating systems, socio economic benefits and challenges

Anaerobic Digestion (AD) is one of the promising wastestoenergy (WtE) technologies that convert organic wastes to useful gaseous fuel (biogas). In this process methane is produced in the presence of methanogens (bacteria). The survival and activities of methanogens are based on several parameters such as pH, temperature, organic loading rate, types of biodigester. Moreover, these parameters influence the production of biogas in terms of yield and composition. Maintaining an appropriate temperaturefor AD is highly critical and energy intensive. This study reviews the various hybrid technologies assistedbio gas production schemes particularly from renewable energy sources. Also discuss the direct and indirect solar assisted bio-digester impacts and recommendation to improve its performance. In addition, the performance analysis Solar Photovoltaic (PV) and thermal collector assisted bio gas plants; besides their impact on the performance of anaerobic digesters. Since opportunities of solar energy are attractive, the effective utilization of the same is selected for the discussion. Besides, the various constraints that affect the yield and composition of biogas are also evaluated along with the current biogas technologies and the biodigesters. The environmental benefits, challenges and socio-economic factors are also discussed for the successful implementation of various technologies.

Techno-economic analysis of control strategies for heat pumps integrated into solar district heating systems

This present work focuses on assessing the techno-economic benefits of different control strategies for a heat pump integrated into the solar assisted district heating system (SDHS). The system has been developed using dynamic simulation software (TRNSYS) and optimized based on a genetic algorithm. With an industrial-sized heat pump connected to thermal storage tanks for domestic hot water (DHW) and space heating (SH) for the requirements of the community, a SDHS is operated by applying two different control mechanisms for the heat pump based on its reference operating temperature. The application of the methodology is applied to a residential neighborhood community of 10 buildings located in Madrid to act as a proxy for the Mediterranean climates. The results showed a significant effect for the heat pump control in the techno-economic benefits where the proposed system is able to provide a solar fraction up to 99%. Furthermore, the total electricity consumption of the heating system varied by 10% between the best and the worst cases. Besides, the annual seasonal storage efficiency improved up to 90% with a life cycle expense up to 67.12 Euro/MWh, and a payback period of 29 years.

Study of novel solar assisted heating system

The potential for energy, carbon dioxide equivalent (CO2e) and cost savings when using low emissivity (low-ε) transpired solar collectors (TSCs), combined with heat pumps in a range of configurations, has been investigated using computer modelling. Low-ε TSCs consist of metal solar collector plates with a spectrally sensitive surface, perforated with holes. Ambient air is drawn through the holes and heated by convection from the solar collector plate, increasing the air temperature by up to 25 K. The heated air can be used for e.g. space heating, or pre-heating water in buildings. The models developed have been used to compare the performance of low-ε TSC/heat pump heating systems in small and large buildings, at a range of locations. The model results showed savings in energy, CO2e and costs of up to 16.4% when using low-ε TSCs combined with an exhaust air heat pump compared with using the exhaust air heat pump alone. Practical application: If the UK is to meet its target of reaching net zero greenhouse gas emissions by 2050, it will be necessary to adopt low or zero carbon heating technologies. The novel low emissivity transpired solar collector device investigated can contribute to this. Its advantages include: (i) utilising solar radiation; (ii) readily integrated with existing heating systems e.g. heat pumps; (iii) significant energy, CO2e emissions and cost savings; (iv) low cost device; (v) minimal energy input i.e. one small fan; (vi) can be retrofitted to existing buildings; (vii) its benefits were applicable at all of the (wide range of) locations tested.

Validated TRNSYS Model for Solar Assisted Space Heating System

The present study involves a validated TRNSYS model for solar assisted space heating system as applied to a residential building in Jordan using new detailed radiation models of the TRNSYS 17.1 and geometric building model Trnsys3d for the Google SketchUp 3D drawing program. The annual heating load for a building (Solar House) which is located at the Royal Scienti?c Society (RS5) in Jordan is estimated under climatological conditions of Amman. The aim of this Paper is to compare measured thermal performance of the Solar House with that modeled using TRNSYS. The results showed that the annual measured space heating load for the building was 6,188 kWh while the heati.ng load for the modeled building was 6,391 kWh. Moreover, the measured solar fraction for the solar system was 50% while the modeled solar fraction was 55%. A comparison of modeled and measured data resulted in percentage mean absolute errors for solar energy for space heating, auxiliary heating and solar fraction of 13%, 7% and 10%, respectively. The validated model will be useful for long-term performance simulation under different weather and operating conditions.