Abstract— This contribution presents a numerical simulation
of water temperature fluctuations in overhead water tanks
commonly used in intermittent water supply systems. Two types
of over head tanks with different sizes were modeled; fiberglass
tank and galvanized steel tanks. The numerical calculations
were based on the actual outside tank temperature measured
during the summer of 2009 in the city of Jeddah, Saudi Arabia.
The numerical and measured water temperatures were in a
good match in both tanks. The field and numerical
investigations indicate that the water temperature in overhead
tanks exceeds safe and comfortable temperature range for
regular use in mid-day hours and it is expected that a
considerable amount of valuable water will be wasted as the
residents draining out the hot water from the plumbing system.
Besides it is quite possible that scalding in sensitive skins may
occurs to some consumers. This valuable water can be saved and
possible scalding can be avoided by changing the current
plumbing practices in hot regions. This may be achieved by
providing the overhead tanks with a temperature controlled
valve that allows the hot water to circulate from overhead tank
and the external piping system to the underground water tank
and maintain an acceptable water temperature in overhead
tank. A better control of the water temperature can be achieved
if the overhead tank is completely eliminated from the system
by installing a booster pump that pumps water directly from
underground tank into the plumbing system and eliminating all
the external pipes from the plumping system.