As an attempt to be civilized or stay married, if you will, I shower at least once a day. Our house is brand new but when I want hot water in the shower I turn on the cold tap and when I want cold water, which I always do, I turn on the hot tap.
You may be thinking, oh the plumber swapped the two by mistake, but our plumber is fine. This mystery has a slightly more advanced explanation.
The “cold” water tap is connected to a large rooftop plastic tank. The tank is placed on the roof so we can enjoy gravity-pressured water in the house. The rooftop tank is black so after 12 hours of sunshine it is sometimes almost scalding hot. That is the explanation for the “cold” water being hot at the end of the day, but how does the warm tap then manage to be cool?
Well, the hot water is also connected to the rooftop tank but is then directed into a water heater placed inside the top corner of the bathroom. If we want hot water we can turn on the water heater, but believe you me, nobody wants hot water in Dar, so we never turn it on. This hot water is cool because the heater is placed inside the house, shaded, and provide for a wonderful cool evening shower.