Have a look at the rating tables for most finned-tube baseboard sold in North America and chances are you’ll see a footnote under the table that reads something like this: “Ratings are based on active fin length and include 15% heating effect factor.”
There are hydronic design concepts in which flow must pass backward through a non-operating circulator, perhaps thousands of times over the life of the system.
A schematic, very similar to the one below, appears in a manufacturer’s installation manual. It represents the manufacturer’s recommendation for installing a two-zone system. Can you identify at least five things that could be changed to improve this system?