ABSTRACT
All nations of the world depend on fossil fuels for their energy needs. However the obligation to reduce Carbon dioxide and other gaseous emissions is the reason behind which countries turn to non-polluting renewable energy sources. Hot water heated by the sun is used in many ways, in residential settings to provide domestic hot water, also has industrial applications, e.g. to generate electricity. Designs suitable for hot climates can be much simpler and cheaper, and can be considered an appropriate technology for these places. Hot water use represents a large proportion of energy needs in hostels. This energy need accounts for a large portion of the total annual energy consumption in hostels and therefore a reasonable amount of the university income is spent on electricity bills used for heating water for bathing in hostels. A solar water heater was designed, simulated, fabricated and tested. The design, simulation, fabrication and performance tests of a thermosyphon solar water heater were carried out successfully for a block in Postgraduate hostel of Ahmadu Bello University Zaria. the fabrication was carried out using locally available materials. The solar water heater has the ability to heat 200 liters of water from a temperature of 25oC to a temperature of 500C,. The design was purposely for students to use the water for bathing in order to totally discourage the use of electric heating devices in the hostel which on several occasions has been the reason of fire outbreaks in the hostel. The system factors such as costs and sizing were taken into consideration which assisted in the choice of materials and the design. The average solar radiation data was obtained from typical meteorological year (TMY) of Zaria which was used to determined the month with the least solar radiation. From the analysis of the typical meteorological year (TMY) data of Zaria the month of August has the least energy ratio which point it out as the month with the least solar radiation and it was used as the design month.The optimization of the system components was also carried out using MATLAB to determine the optimum system size. After the fabrication of the system the performance was evaluated by comparing the simulation results obtained from the model (solar data processor, Type 109 of TRNSYS) and the results obtained from the experiment using Microsoft Excel and standard deviation, Nash-Sutcliff coefficient statistical tools were used to validate the predictive power of the model. From the result obtained from the research it can be concluded that the thermosyphon solar water heater of collector area of 2.6m2 has the ability to heat 200 litre of water to a temperature of 500C in the month that has the least solar radiation in Ahmadu Bello University Samaru, Zaria.The statistical tools used for the validation of the simulation model confirm that the model is valid and can be used in the estimation of the actual characteristics of a real system. The relative error is very minimal for all the measured parameters and Nash-Sutcliff coefficient shows that the degree of fitting is very high which shows that the simulation model has high accuracy, also the standard deviation shows that the deviation of the experimental parameters from the simulated is very low and therefore it is negligible.The results show little deviation of predicted values from actual values with a good level of fit, thereby validating the model used for simulating the solar water heating system.