Solar Newb

Inside a building we found two of these panels, that hopefully show up in the pictures.
Can anyone tell me what they are used for?
They appear to be about 4x10 and 4 inches thick.
Thank you in advance.

I strongly suspect those are solar hot air panels, i.e. solar thermal panels. A picture of the back and sides would likely reveal two ducts for an inlet and and outlet for the air.


troy