Evaporator airflow question

[zippy_gg]

The bottom of the evap box has that trapezoidal hole connecting to the passenger footwell, a small condensation hole at the bottom (self-explanatory), and the 80 mm hole going toward the bottom of the smuggler's box.
It is my understanding that the trapezoidal hole is the "return" or intake going from the cabin to the fan.
The top of the evap has an 80 mm hose bringing the cool air from the fan to the inside of the car.
What is the bottom 80 mm hole for? Is it redundant since there is already air coming from the cabin to the evap box?

[Ronnie's.930]

Gilles, are you referring to the large round hole in this pic? If so, that is the evaporator intake from the intake duct on the driver's side, beneath the dash.

[SilberUrS6]

IIRC, there are three openings. One for the inlet from the cabin, and two for outlet to the cabin. One outlet goes to one side of the car, and the other to the other side of the car. Someone will correct me if I am wrong - every time I look at the car's HVAC system, I think "Rube Goldberg".

[zippy_gg]

Yes Ronnie, that is the one.
So we have 2 air intakes, both coming from the cabin... Now that makes sense. Thanks!

[Ronnie's.930]

Gilles, the a/c is always in "air recycle" mode in these cars - no option there for pulling in outside air and directing it at the evaporator intake (other than a window down, or cabin air leaks in general, buttofcourse ).

And the reason for that second evaporator intake is that it is an attempt by Porsche to balance the a/c effect in the cabin - to pick up air from the left and the right, as opposed to just picking it up from the right.

[Ronnie's.930]

Originally Posted by SilberUrS6

IIRC, there are three openings. One for the inlet from the cabin, and two for outlet to the cabin. One outlet goes to one side of the car, and the other to the other side of the car. Someone will correct me if I am wrong - every time I look at the car's HVAC system, I think "Rube Goldberg".

Eric - that would be two inlets and one outlet, bub (sounds kinky, I know)!

[SilberUrS6]

Originally Posted by Ronnie's.930

Eric - that would be two inlets and one outlet, bub (sounds kinky, I know)!

Thanks for the correction. Like I said, the HVAC on these cars makes me crazy. Crazier, that is.

[88911coupe]

Is there any chance of the 2nd/round intake route from the driver wheel well to have laaks and allow hot/outside air to be pulled in? Or is it all solid sheetmetal?

[Ronnie's.930]

Originally Posted by 88911coupe

Is there any chance of the 2nd/round intake route from the driver wheel well to have laaks and allow hot/outside air to be pulled in? Or is it all solid sheetmetal?

Nope, it is a solid metal pipe. It is possible for the air to leak around the intake opening, however, because remarkably, the evaporator box just sits on top of the round hole and the only sealing against air from the smuggler's box (including air that can be drawn in from the area of the steering rack) is done with a foam ring glued to the box. To help prevent this, I put an appropriately sized piece of heavy duty (black foam rubber type) weather stripping around the inside perimeter of the intake pipe (in the "groove" - weather stripping pokes up just above the groove after stuck in place), and I made a round gasket out of thick, cork rubber material that I glued to the corresponding opening on the evaporator box. I test fit the box several times to make sure of a good seal there. Not to mention that packing the smuggler's box with insulation helps stop air leaks, too.

[zippy_gg]

Things to do to rehab my A/C, if weather gives me a break today:





If local pelicans need to have an AC hose made...

[zippy_gg]

Originally Posted by Ronnie's.930

Nope, it is a solid metal pipe. It is possible for the air to leak around the intake opening, however, because remarkably, the evaporator box just sits on top of the round hole and the only sealing against air from the smuggler's box (including air that can be drawn in from the area of the steering rack) is done with a foam ring glued to the box. To help prevent this, I put an appropriately sized piece of heavy duty (black foam rubber type) weather stripping around the inside perimeter of the intake pipe (in the "groove" - weather stripping pokes up just above the groove after stuck in place), and I made a round gasket out of thick, cork rubber material that I glued to the corresponding opening on the evaporator box. I test fit the box several times to make sure of a good seal there. Not to mention that packing the smuggler's box with insulation helps stop air leaks, too.

I am tackling this right now...

[Ronnie's.930]

^^^ You and Nathan are a bad influence on my wallet - I've now got wood for one of those hose crimper machines since I have plans to eventually remove/relocate my tail condenser, replace all the hoses, etc., and the thought of doing the custom hose building myself is very appealing.

[SilberUrS6]

Dual fenderwell set-up, Ronnie? I've been thinking about that, too.

[Ronnie's.930]

Yep Eric. I have a nice, Garettson 1/2 bay, but Paul recently installed a full bay intercooler (can get them custom made from Bell at a sort of reasonable cost), so I've got some serious size-envy going on about that, and I also like the idea of removing the condenser heat source from my engine bay. The additional heat is probably not of any real consideration for those living in "not to hot" climates, but at this time of year around here, and the car being a Turbo, it is difficult to keep the oil at optimal temps (220F) - any type of traffic, errand running (stop/start, low rpm), etc., in upper 90s, and I see around 240-245 on a regular basis. Not an oil temp I consider to be overly alarming, but 220 is better.

[zippy_gg]

Originally Posted by Ronnie's.930

^^^ You and Nathan are a bad influence on my wallet - I've now got wood for one of those hose crimper machines since I have plans to eventually remove/relocate my tail condenser, replace all the hoses, etc., and the thought of doing the custom hose building myself is very appealing.

I'll let you borrow the tool just for shipping.

[Ronnie's.930]

^^^ What a generous offer! I'll keep that in mind when the time comes. Does that tool have small sized dies that could be used for crimping fuel hose fittings? I've got some "custom" plans for fuel hoses, too.

[zippy_gg]

Originally Posted by Ronnie's.930

^^^ What a generous offer! I'll keep that in mind when the time comes. Does that tool have small sized dies that could be used for crimping fuel hose fittings? I've got some "custom" plans for fuel hoses, too.

Alas no. The smallest size is #6, which is way too big, and I don't think that tool can take small dies such as used for fuel lines. Perhaps Len can answer that question.

[Pazuzu]

Originally Posted by Ronnie's.930

^^^ You and Nathan are a bad influence on my wallet - I've now got wood for one of those hose crimper machines since I have plans to eventually remove/relocate my tail condenser, replace all the hoses, etc., and the thought of doing the custom hose building myself is very appealing.

So...I shouldn't mention that I too have bought one, and mine is within your state...

[zippy_gg]

Originally Posted by Pazuzu

So...I shouldn't mention that I too have bought one, and mine is within your state...

Actually it is your fault I bought the tool...

[KelogGes]

Originally Posted by zippy_gg

Things to do to rehab my A/C, if weather gives me a break today:



nl

If local pelicans need to have an AC hose made...

G,
FYI; MAKE SURE YOU HAVE THE RIGHT DIES for your intended hose, AND FITTINGS you bought

I HOPE these die's are for "REDUCED BARRIER HOSE" AND NOT STANDARD BARRIER HOSE" IF YOU ARE USING REDUCED BARRIER HOSE ?


THIS cripper I think normally only comes with WITH STANDARD SIZE HOSE SIZEs unless you ordered it special WITH THE additional REDUCED barrier SIZE HOSE DIES??? or ordered them separately?