Climatizer hole? And excessive heat

[DobbM]

Hello all. I'm trying to cool off the cabin. I checked the butterfly vents and they are fine. But as I was under the passenger side dash I was looking at the heater box/core area. To the left side is a hole, 2" x 1.25-ish inches and about 4 inches deep. The hole looks intensional, but not factory (super smooth edges, etc.). Was it the place for the filter? 

[ronmanfredi]

38 minutes ago, DobbM said:

Hello all. I'm trying to cool off the cabin. I checked the butterfly vents and they are fine. But as I was under the passenger side dash I was looking at the heater box/core area. To the left side is a hole, 2" x 1.25-ish inches and about 4 inches deep. The hole looks intensional, but not factory (super smooth edges, etc.). Was it the place for the filter? 

That is where the heated air comes into the floorboard foot area.

[DobbM]

Oh, I thought that was pre blower. Should there be a flap there? It is the 'Heat'/'Defrost' diverter elsewhere?

And since I don't drive the car in the Michigan winters, would it be safe to cover it?