On Wednesday, December 26, 2018 at 8:16:20 AM UTC-8, wrote:
On Tuesday, December 25, 2018 at 11:53:19 PM UTC-6, wrote:
As we know, flying in wave with the sun shining, much of the cockpit stays reasonably warm, but the feet, down in the shade, get cold. So, as I'm here at home on a cold night with a fan helping distribute the heat from the wood stove to another room, it occurred to me that something like that may be possible in the cockpit? A small fan (using a fraction of the electric power that the typical instrument panel uses), perhaps with a short duct, could move sun-warmed air towards the feet. Has that been tried? Does it help? Would it use more electrical power than electrically heated insoles?

Back when I flew an HP-14 which had a canopy that extended forward over the rudder pedals, my feet were much warmer in cold but sunny weather than they are in my current glider. As long as I was pointed towards the sun, that is - typically pointed into a West wind in the afternoon. As soon as I turned around to the East the cockpit temperature plunged.

Have been flying now for 5 years with these Gerbing insoles and the recommended temp controller, also from Gerbing.
https://www.revzilla.com/motorcycle/...caAvYwEALw_wcB
I run them on a dedicated 12V LiFePo4 battery. After 2 hours at altitude when the feet get cold I turn the unit on and dial the controller back to a setting that I tested prior to keep my feet toasty but not hot. I know of at least 4 pilots who also use these with no issues.
Herb

The Gerbing line seems to be the industry standard. They work well.
The cheap stuff gets bad reviews.
Don't do as one USAF Test Pilot School pilot tried, chemical warmers inside a pressure suit, unless you enjoy burns.
Jim