Heat and mass exchanger fin inserts

A heat transfer assembly comprising:

• two parallel heat transfer tubes spaced apart from one another;
• a fin insert comprising a generally rigid, longitudinally-extending member comprising a top portion and side portions disposed on opposite edges of the top portion, the fin insert being disposed between the two parallel heat transfer tubes;
• a plurality of spacers disposed between the side portions of the fin insert and a respective heat transfer tube, such that the fin insert is spaced apart from the heat transfer tubes;
• and
• at least one fluid channel formed between at least two spacers.

A heat transfer assembly, comprising

• a generally rigid and corrugated sheet comprising a fluid flow channel disposed between two mounting portions;
• and
• a heat transfer tube, a portion of which resides on least one of the two mounting portions;
• wherein the fluid flow channel comprises a groove of the corrugated sheet and is shaped to direct a fluid to flow towards a drain hole of the fluid flow channel, and
• wherein the two mounting portions are shaped to direct the fluid to flow towards the fluid flow channel.