Quote:
Originally Posted by astral_car  I still don't fully understand why, but I trust you 
cheers,
a. |
In this case the construction of the box leaves (or looks to leave) plenty of airspace between the insulation and the hard back. If it were stuffed front to back with insulation, leaving no airspace, then that would not be good. Alternately one could build a panel like we build ours...with airspace between the layer of insulation and the wall you mount it on.
Frank