Hi Obiajulu,

The following link may be helpful for you.

http://www.chromalox.com/catalog/resources/technical-information/Heat-Loss-Calculations-and-Heater-Selection-Pipe-Tank-Tracing.pdf

Let us know how you go.

Kind regards,

Sazal

Thanks Abdul, that was really helpful. For a rectangular tank, there are both vertical and horizontal plate orientations with different values for convection heat transfer coefficients, which value is appropriate to be used in the formula for exponential temperature decay. Is it possible to consider the different orientation separately, then combine into one overall heat transfer coefficient? Also which area should be considered? The inner area, or the outer area (after insulation)?

Thanks.