I for one consider advanced farms "a fancy man's type of meals" - something more mid-game and for the sake of refined diversity. As efficiency goes you can opt for Bacon and Eggs, Meatballs, and/or Meaty Stew. But after you have a well developed base and pretty much thrive, you can gorge on Honey Ham, Dragon Pies, Fruit Medley, even Melonsicles (well depends what you want/need atm) - and here is where you experiment with recipes based on farm ingredients.
Interesting idea, I'll give it a shot. This design is limited by how hot the inlet water is and since most polluted water you find is >30 degrees the output water can't be any cooler than it. Your idea works, I can probably do away with the active cooling section and save even more power.