I am designing a portable distiller powered by the sun. I will be heating the water with a heating coil and then when the water evaporates I will be collecting the stem in a metal tube(not sure what type of tube yet). I need the steam to condense back into the water as fast as I can, so my idea was just to put heatsinks around the tube. I am not sure if that is the best method, should I just put another tube over my steam tube and have a pump push water on the outside of the steam tube? Should I just have two fans one for intake and one for exhaust, or should I just add heat pipes and one smaller 80mm fan? Maybe a 1watt pump, not sure if that will more a lot of water though. Thanks!
"Cooling" is the transfer of heat from an area of higher heat to one of lower heat. Transferring the heat of your tube to a heat sink is only one step, you then have to transfer the heat of the heat sink to something else. Air works, but if the air is not moving, it acts like an insulator. Think of what insulation is doing in your walls; is is trapping air so that it cannot move, so heat becomes trapped in it. So all the fan is doing is ASSISTING the heat in getting OUT of the heat sink. You can do it without fans, IF you have enough surface area in the heat sink to allow for natural convection to remove the heat. But there are limits to this too, because while the heat is moving THROUGH the heat sinks to the fins in order to radiate and dissipate into the air, it might be building up in the immediate junction area with your device to the point of causing damage. So the fans accelerate that movement of heat for you in order to avoid that. But depending on the ambient conditions, the amount of heat created, the surface area of the heat sink and the availability of convection flow, you may not need fans.