Cold well water and high humidity cause serious moisture problems on wall pipes in this area of the country. Would like to develop pipe-in-pipe system to carry cold water in the core pipe and hot in the jacket pipe. Yes, there would be heat equalization, but not a problem. Where can I find such a product -- or is there a reader with experience in making such a device?
If you don't want to do the insulation for some reason, I would recommend a gutter system. Rather than enclose one pipe in another, run a "tray" underneath the pipe. This is much, much easier to implement and maintain.
You could use rain gutters designed for the edges of roofs. Or, for more flexibility with connectors, I suppose you could slice PVC pipe down its length and use PVC elbows and tees. Slicing PVC down its length is somewhat difficult and requires the correct setup.