Heaterbox identification!

You could take out the evaporator out of the box, and remove any un-needed ducting. The housing is made out of fiberglass, pretty light already. Plus, if you ever get tired of sweating your body off in those Midwest summers you could re-install it. :D

I looked at my box and it didnt look like I could separate the 2 sections. I can take a look again though. Thanks for the idea.