Where does the "other" hole in the 911sc evaporator box go?

[ohecht]

I just R&R'd my entire AC system (blowing in the mid-30s now!) but have a question about one of the holes in the evaporator housing and smuggler's box. There is the trapezoidal hole that goes to the passenger footwell and brings air from the cabin through the evaporator, and the round hole at the blower output that directs cold air into the dashboard vents, but there is also a second round hole below the evaporator, closer to the center of the car than the trapezoidal hole. In the attached picture (not my housing but identical), it's the round hole at the bottom of the picture.

It's about 2-3" in diameter. I've heard that it might be from the old gas heater set up, but I'm not sure where it goes, and I want to make sure my system is not somehow bringing in hot outside air in addition to the cabin air it's cooling down (I want to make sure it's permanently in what would be "recirc" mode in a more modern system).

Does anyone know where this hole goes? Is it to the outside of the car, the heating system, or just to the driver's footwell area to bring more cabin air through the system.

Thanks in advance,

Olivier

[JAR0023]

Round hole in bottom of smuggler's box runs to front of central tunnel. Tunnel is open on left side (throttle/clutch linkages). Tunnel also has opening on top at front. Evap box pulls return air from both trapezoid shaped hole in passenger footwell and the round hole at the head of the tunnel. -J

[Bob Kontak]

Originally Posted by JAR0023

Evap box pulls return air from both trapezoid shaped hole in passenger footwell and the round hole at the head of the tunnel. -J

Outstanding. Have had this car for close to 20 years and never knew this.

[sacoffee]

Is the tunnel open to outside air or heat from engine compartment?

[Chinook]

Howdy, I am replacing various gaskets and seals and am wondering what exactly is the seal/gasket that seals this 2-3 inch hole from the center tunnel to the evap box. The tube from the tunnel is expanded like there is some kind of insert or something. There was some foam remnants on the box as well as where some kind of seal was glued on the box around the hole. Is it just a flat piece of foam that the tube from the tunnel butts against? ( which would be a funky fit in my mind)

Thanks Great Site, Gary