INTERNATIONAL JOURNAL OF LATEST TECHNOLOGY IN ENGINEERING,
MANAGEMENT & APPLIED SCIENCE (IJLTEMAS)
ISSN 2278-2540 | DOI: 10.51583/IJLTEMAS | Volume XIV, Issue XII, December 2025
Design, Construction and Testing of a Model Thermosiphonic Solar
Water Heater
*Chikak Ishaya Gokir and Aliyy Muhammad Ajadi
Department of Mechanical/Production Engineering, Faculty of Engineering and Engineering
Technology, Abubakar Tafawa Balewa University, Bauchi
*Corresponding Author
Received: 18 December 2025; Accepted: 26 December 2025; Published: 05 January 2026
ABSTRACT:
A thermosiphonic solar water heating system that uses a simple flat plate collector to heat water and in which
circulation takes place with natural convention. The system was designed, constructed and tested at Yelwa
campus, ATBU Bauchi with latitude 10.330N and longitude 9.830E. The system was designed to heat a total of
15litres of water between 500 and 800 at the worst and best month of the year respectively. The system was
designed using weather data of Bauchi state and the resulting parameters of the design was used to construct the
system. It was tested between December and January. Two tests were carried out on the system; for the system
with ordinary collector, and that with diffusers incorporated within the collector risers. The first system (without
diffusers) has an efficiency of 52.6% and was able to generate collector outlet temperature of 610C and water
mean temperature of 600C at an average daily solar radiation of 912W/m2. In contrast, the second system (with
diffusers) has an efficiency of 58.6% and was able to generate collector temperature of 700C and water mean
temperature of 680C at an average daily solar radiation of 913.3W/m2. It was concluded from the results that
incorporating diffusers within risers improved the performance of the system by 6.6%.
INTRODUCTION
Several challenges such as increase in oil demand and oil price rise, depletion of oil reserve, reduced availability
of fossil fuels, ozone layer depletion, health hazards, global climate change and other air pollution issues caused
mainly by burning of hydrocarbons as source of heat energy, has led to the drive to use environmental friendly
and renewable alternatives sources of heat energy to eliminate or minimize these negative effects. Presently,
solar and other alternative energy sources like wind and geothermal are being harnessed for various applications
such as power generation, air conditioning, space heating, domestic hot water system etc.
Supply of hot water account for a high level of energy demand in homes. This calls for the utilization of a cheap
and renewable energy sources to provide an effective and efficient supply of hot water for maximum energy
savings.
Renewable energy resources of which the sun is a good example are those resources which undergo faster
replenishment rate within a relatively short time than the rate at which they are utilized or depleted. The energy
of the sun is generated from its nuclear fusion of its hydrogen into helium, with a resulting mass depletion rate
of approximately 4.7x106tons/second. The earth’s population currently needs 15 terawatts of power in total, but
the solar radiation that reaches the earth on a continuous basis amount to 120,000 terawatts; hence, just a fraction
of the suns energy reaching the earth will cover the bulk of energy requirements. (Bradke et al., 2011)
In harnessing the solar energy for heating, the solar radiation has to be converted to heat energy. Solar energy
collectors, the device used to convert the solar radiation to heat, usually consist of a surface that efficiently
absorbs radiation and convert this incident flux into heat which raises the temperature of the absorbing material.
A part of this energy is then removed from the absorbing surface by means of heat transfer fluid that may either
be liquid or gaseous.
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