When Fela of blessed memory said,”Teacher don’t teach me nonsense,” little did I know that one day he might be referring to me. I just realized that since the past one year I have been teaching visitors to my house “nonsense” about the working principles of a solar water heater. So, may I ask that if you have been to my house in the past one year and had this lesson, kindly “Self Isolate” yourself when it comes to any group discussion about the subject until you take this refresher training. And do not ask me why I am using that COVID19 language “Self isolate”. After all it fits better here than as used by the Anambra state government in planning for the “flattening of curve” when they got only an index case.
Using my common sense, I had taught my students that the water from overhead tank gets split into the about twelve tiny two feet glass tubes they see on my roof. The splitting I had taught them, was to get the water into smaller batches that is heated by the sun fast. Then the hot water rises with buoyancy given its lighter weight to cold water. It then gets stored in the larger tube to which all the smaller tubes are attached. The larger tube is positioned on top of the smaller tubes which are slanted with the landing of the roof. What is annoying me now and some of my stakeholders is the confidence with which I dished this nonsense!
In a bid to understand better the principles of how the boiler works, I asked Google. My quest was to understand how the solar boiler was integrated with an electric heating element such that one can use electric to heat water when it rains the whole day and we don’t have hot water from the sun. That investigation revealed my ignorance. It turned out that the glass tubes I saw are called collectors and had a second layer, and within that second layer was a copper rod. That second layer is coated with a heat absorbing chemical, and within it is also a volatile fluid. The tubes absorb the heat; pass it to the copper rod and it heats up the volatile fluid. The volatile fluid carries the heat as it evaporates and rises up to the larger tube to which those smaller solar tubes are connected. In the larger tube, the heat gets transferred by way of heating the water in the larger tube. The evaporated volatile tube then condenses and returns to the bottom of the smaller tubes and the cycle begins again. Hence, the volatile fluid is in a closed system and never mixes with the water that goes to the house. No water from the tank is split before going into any smaller tubes like I had taught my students. The water from the tank does not go into the smaller tubes at all but directly to the larger tube where the heat exchange happens. The revelation of the working principle was interesting. Even more interesting was how the auxiliary electric element is incorporated in the design and the explanation for some other surprises I got from the use of the system. For example, you may have to wait a while when you open the hot water tap to be able to get hot water. That is explained by the fact that the auxiliary element is in a separate chamber and it is from that chamber that the house gets fed. You can imagine that as the solar heats the main solar chamber, it takes a lot of dynamics to get the heated water into the auxiliary chamber and this is peculiar to my horizontal design. Vertical designs will not have this problem.
The electric element made a very good sense since where I live, we have rainfall a lot during the year and we have some days without sun. Meanwhile, can you imagine that my vendor did not install the damn element for over a year! It took my calling him out, threatening to go to EFFC and report him to police fraud unit (all na wash!) for them to do the needful. I had called them up on a Saturday, shouting and threatening like a mad man and gave them a deadline of Monday to install it. The response I got was that I was behaving like a kid! I retorted they were behaving unprofessionally as well. I eventually calmed down but gave them my feedback anyway while praying that my shouting will at least awaken their conscience of their responsibility to a client. My brother, by Monday, I did not hear anything. Thinking I had failed, I made up my mind not to engage them again and would rather find another vendor to come do the electric element installation. To the glory of God, they called on Tuesday morning and informed me they will be coming to install the damn thing in the evening. By 4pm they came to my house while I was sleeping. Before I knew what was happening they had finished, left and the job did not take more than thirty minutes! Thirty minutes, my brothers and sister! And I was like, why didn’t I act this mad this past one year? That is the Nigerian professional for you.
Anyway back to Fela and common sense, please whatever you are teaching your students, make sure you have a proper understanding before you teach them nonsense and do not feel shy or proud to recall any past lessons you goofed like me!
Obidike Peter wrote from www.peterobidike.com and email@example.com
Sunday 19th April, 2020.
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