IIRC, the backside of some of my PV was up around 120 to 150F.
You might not need to mount each panel as the lid of an air-box.
Maybe just mounting them pressed up against each other would work.
Then, you could build a little 4" wall around the outside edge of the array. One big hot air collector box!
Blow cool house air into the bottom of the array (spread it with manifold dams)
and suck heated air out the top..
Just what I need to heat my basement in the winter time..
Summer might be a problem..