heat transfer coil in solar cylinder 1

[P713]

Hi
Does anyone know a simple formular for working out the area of the heat transfer coil required in a solar heating system:- for example a formular linking area of heat transfer coil to the area or kW output of the solar panel. The transfer liquid is water+antifreeze......Or is it more complicated than this?

 

[willard3]

It is way more complicated than that as heat exchanger configuration is important, log mean temp difference is important and etc......