Front heat vents in the RV10 send air parallel to the firewall rather than directing it aft. Those of us who live in northern climes would prefer it to warm our toes and not the firewall. To that end I have created a small duct that directs warm air aft. In a recent flight it definitely made a difference.

To install, pull pack the tunnel carpeting, and inset this into the vent hole. The carpet then fits over the curved portion of the duct.

Rotate the duct so warm air is sent aft or anywhere else you desire.

Here is the 3D printer file.