Underbelly heat duct

[Chisel plow]

I'm preping for winter hunt. I have a m26 mallard 2022. I noticed that the heat duct for the belly is a 4" , it goes threw the floor but does not go threw the floor insulation. Should I open up the insulation for duct. And 4" seems quit large for belly heat.
Any thoughts!

 

[david-steph2018]

Generally, the underbelly heat is an open duct from the furnace to the open space.

 

[sengli]

If its super cold, and especially windy the ducted belly heat wont really save you. The coroplast belly covering isnt really more than a splash shield.